1 00:00:26,880 --> 00:00:29,109 as part of a continuing program on 2 00:00:29,109 --> 00:00:29,119 as part of a continuing program on 3 00:00:29,119 --> 00:00:31,029 as part of a continuing program on aviation safety the lewis flank 4 00:00:31,029 --> 00:00:31,039 aviation safety the lewis flank 5 00:00:31,039 --> 00:00:32,870 aviation safety the lewis flank propulsion laboratory of the national 6 00:00:32,870 --> 00:00:32,880 propulsion laboratory of the national 7 00:00:32,880 --> 00:00:34,709 propulsion laboratory of the national advisory committee for aeronautics has 8 00:00:34,709 --> 00:00:34,719 advisory committee for aeronautics has 9 00:00:34,719 --> 00:00:36,870 advisory committee for aeronautics has been engaged in research on the start of 10 00:00:36,870 --> 00:00:36,880 been engaged in research on the start of 11 00:00:36,880 --> 00:00:39,110 been engaged in research on the start of fires that sometimes follow airplane 12 00:00:39,110 --> 00:00:39,120 fires that sometimes follow airplane 13 00:00:39,120 --> 00:00:41,430 fires that sometimes follow airplane crashes the work was undertaken at the 14 00:00:41,430 --> 00:00:41,440 crashes the work was undertaken at the 15 00:00:41,440 --> 00:00:43,670 crashes the work was undertaken at the recommendation of the naca committee on 16 00:00:43,670 --> 00:00:43,680 recommendation of the naca committee on 17 00:00:43,680 --> 00:00:46,069 recommendation of the naca committee on operating problems and the subcommittee 18 00:00:46,069 --> 00:00:46,079 operating problems and the subcommittee 19 00:00:46,079 --> 00:00:48,790 operating problems and the subcommittee on aircraft fire prevention these groups 20 00:00:48,790 --> 00:00:48,800 on aircraft fire prevention these groups 21 00:00:48,800 --> 00:00:50,630 on aircraft fire prevention these groups are made up of leading representatives 22 00:00:50,630 --> 00:00:50,640 are made up of leading representatives 23 00:00:50,640 --> 00:00:53,350 are made up of leading representatives of civil and military aviation it was 24 00:00:53,350 --> 00:00:53,360 of civil and military aviation it was 25 00:00:53,360 --> 00:00:55,270 of civil and military aviation it was the purpose of this research to provide 26 00:00:55,270 --> 00:00:55,280 the purpose of this research to provide 27 00:00:55,280 --> 00:00:57,110 the purpose of this research to provide a better understanding of the important 28 00:00:57,110 --> 00:00:57,120 a better understanding of the important 29 00:00:57,120 --> 00:00:59,430 a better understanding of the important factors involved in the start and spread 30 00:00:59,430 --> 00:00:59,440 factors involved in the start and spread 31 00:00:59,440 --> 00:01:02,709 factors involved in the start and spread of crash fires as a necessary first step 32 00:01:02,709 --> 00:01:02,719 of crash fires as a necessary first step 33 00:01:02,719 --> 00:01:04,710 of crash fires as a necessary first step leading to significant reduction in the 34 00:01:04,710 --> 00:01:04,720 leading to significant reduction in the 35 00:01:04,720 --> 00:01:06,630 leading to significant reduction in the crash fire hazard 36 00:01:06,630 --> 00:01:06,640 crash fire hazard 37 00:01:06,640 --> 00:01:08,789 crash fire hazard the work reported in this film covers 38 00:01:08,789 --> 00:01:08,799 the work reported in this film covers 39 00:01:08,799 --> 00:01:11,109 the work reported in this film covers only the research completed on airplanes 40 00:01:11,109 --> 00:01:11,119 only the research completed on airplanes 41 00:01:11,119 --> 00:01:13,590 only the research completed on airplanes powered with reciprocating engines 42 00:01:13,590 --> 00:01:13,600 powered with reciprocating engines 43 00:01:13,600 --> 00:01:15,990 powered with reciprocating engines a thorough review of civil and military 44 00:01:15,990 --> 00:01:16,000 a thorough review of civil and military 45 00:01:16,000 --> 00:01:18,710 a thorough review of civil and military crash fire records emphasize the need 46 00:01:18,710 --> 00:01:18,720 crash fire records emphasize the need 47 00:01:18,720 --> 00:01:21,109 crash fire records emphasize the need for well-defined information on how 48 00:01:21,109 --> 00:01:21,119 for well-defined information on how 49 00:01:21,119 --> 00:01:23,109 for well-defined information on how crash fires start 50 00:01:23,109 --> 00:01:23,119 crash fires start 51 00:01:23,119 --> 00:01:25,270 crash fires start this review showed this information can 52 00:01:25,270 --> 00:01:25,280 this review showed this information can 53 00:01:25,280 --> 00:01:27,830 this review showed this information can only be provided by full-scale crash 54 00:01:27,830 --> 00:01:27,840 only be provided by full-scale crash 55 00:01:27,840 --> 00:01:28,870 only be provided by full-scale crash study 56 00:01:28,870 --> 00:01:28,880 study 57 00:01:28,880 --> 00:01:30,870 study findings of this study were published in 58 00:01:30,870 --> 00:01:30,880 findings of this study were published in 59 00:01:30,880 --> 00:01:33,749 findings of this study were published in an naca research memorandum entitled 60 00:01:33,749 --> 00:01:33,759 an naca research memorandum entitled 61 00:01:33,759 --> 00:01:36,069 an naca research memorandum entitled analysis of multi-engine transport 62 00:01:36,069 --> 00:01:36,079 analysis of multi-engine transport 63 00:01:36,079 --> 00:01:40,069 analysis of multi-engine transport airplane fire records 64 00:01:40,069 --> 00:01:40,079 airplane fire records 65 00:01:40,079 --> 00:01:42,390 airplane fire records the need for a full-scale crash fire 66 00:01:42,390 --> 00:01:42,400 the need for a full-scale crash fire 67 00:01:42,400 --> 00:01:44,390 the need for a full-scale crash fire program established the united states 68 00:01:44,390 --> 00:01:44,400 program established the united states 69 00:01:44,400 --> 00:01:46,310 program established the united states air force provided a group of service 70 00:01:46,310 --> 00:01:46,320 air force provided a group of service 71 00:01:46,320 --> 00:01:48,630 air force provided a group of service weary aircraft marked for decommission 72 00:01:48,630 --> 00:01:48,640 weary aircraft marked for decommission 73 00:01:48,640 --> 00:01:50,870 weary aircraft marked for decommission with which to conduct the research a 74 00:01:50,870 --> 00:01:50,880 with which to conduct the research a 75 00:01:50,880 --> 00:01:53,030 with which to conduct the research a landing or takeoff accident was chosen 76 00:01:53,030 --> 00:01:53,040 landing or takeoff accident was chosen 77 00:01:53,040 --> 00:01:55,030 landing or takeoff accident was chosen for study because the chance for 78 00:01:55,030 --> 00:01:55,040 for study because the chance for 79 00:01:55,040 --> 00:01:57,270 for study because the chance for passenger survival of crash impact is 80 00:01:57,270 --> 00:01:57,280 passenger survival of crash impact is 81 00:01:57,280 --> 00:01:59,350 passenger survival of crash impact is highest in this type of crash which 82 00:01:59,350 --> 00:01:59,360 highest in this type of crash which 83 00:01:59,360 --> 00:02:02,069 highest in this type of crash which occurs at reduced airplane speed the 84 00:02:02,069 --> 00:02:02,079 occurs at reduced airplane speed the 85 00:02:02,079 --> 00:02:03,990 occurs at reduced airplane speed the airplanes were carefully instrumented to 86 00:02:03,990 --> 00:02:04,000 airplanes were carefully instrumented to 87 00:02:04,000 --> 00:02:05,990 airplanes were carefully instrumented to collect detailed information during the 88 00:02:05,990 --> 00:02:06,000 collect detailed information during the 89 00:02:06,000 --> 00:02:06,950 collect detailed information during the crash 90 00:02:06,950 --> 00:02:06,960 crash 91 00:02:06,960 --> 00:02:09,749 crash 72 vapor detectors located in the engine 92 00:02:09,749 --> 00:02:09,759 72 vapor detectors located in the engine 93 00:02:09,759 --> 00:02:12,229 72 vapor detectors located in the engine the cell wings and fuselage registered 94 00:02:12,229 --> 00:02:12,239 the cell wings and fuselage registered 95 00:02:12,239 --> 00:02:14,949 the cell wings and fuselage registered the presence of combustible vapors over 96 00:02:14,949 --> 00:02:14,959 the presence of combustible vapors over 97 00:02:14,959 --> 00:02:17,830 the presence of combustible vapors over 100 flame detectors similarly located 98 00:02:17,830 --> 00:02:17,840 100 flame detectors similarly located 99 00:02:17,840 --> 00:02:20,070 100 flame detectors similarly located recorded the origin and spread of fire 100 00:02:20,070 --> 00:02:20,080 recorded the origin and spread of fire 101 00:02:20,080 --> 00:02:22,710 recorded the origin and spread of fire throughout the aircraft structure 102 00:02:22,710 --> 00:02:22,720 throughout the aircraft structure 103 00:02:22,720 --> 00:02:24,710 throughout the aircraft structure all the main electrical circuits were 104 00:02:24,710 --> 00:02:24,720 all the main electrical circuits were 105 00:02:24,720 --> 00:02:26,790 all the main electrical circuits were monitored at the locations shown on this 106 00:02:26,790 --> 00:02:26,800 monitored at the locations shown on this 107 00:02:26,800 --> 00:02:28,869 monitored at the locations shown on this chart to indicate the presence of short 108 00:02:28,869 --> 00:02:28,879 chart to indicate the presence of short 109 00:02:28,879 --> 00:02:29,990 chart to indicate the presence of short circuits 110 00:02:29,990 --> 00:02:30,000 circuits 111 00:02:30,000 --> 00:02:31,830 circuits instrumentation was also provided to 112 00:02:31,830 --> 00:02:31,840 instrumentation was also provided to 113 00:02:31,840 --> 00:02:34,070 instrumentation was also provided to indicate the time at which fuel lines 114 00:02:34,070 --> 00:02:34,080 indicate the time at which fuel lines 115 00:02:34,080 --> 00:02:37,830 indicate the time at which fuel lines ruptured in a crash 116 00:02:37,830 --> 00:02:37,840 117 00:02:37,840 --> 00:02:40,229 such detailed information is registered 118 00:02:40,229 --> 00:02:40,239 such detailed information is registered 119 00:02:40,239 --> 00:02:42,229 such detailed information is registered on this instrument panel inside a 120 00:02:42,229 --> 00:02:42,239 on this instrument panel inside a 121 00:02:42,239 --> 00:02:44,710 on this instrument panel inside a fireproof box carried in the airplane 122 00:02:44,710 --> 00:02:44,720 fireproof box carried in the airplane 123 00:02:44,720 --> 00:02:46,630 fireproof box carried in the airplane the instrument panel is photographed by 124 00:02:46,630 --> 00:02:46,640 the instrument panel is photographed by 125 00:02:46,640 --> 00:02:51,509 the instrument panel is photographed by motion picture cameras within the box 126 00:02:51,509 --> 00:02:51,519 127 00:02:51,519 --> 00:02:53,670 in a crash operation the airplane is 128 00:02:53,670 --> 00:02:53,680 in a crash operation the airplane is 129 00:02:53,680 --> 00:02:56,070 in a crash operation the airplane is accelerated from rest under full power 130 00:02:56,070 --> 00:02:56,080 accelerated from rest under full power 131 00:02:56,080 --> 00:02:58,630 accelerated from rest under full power and is guided into a crash barrier by a 132 00:02:58,630 --> 00:02:58,640 and is guided into a crash barrier by a 133 00:02:58,640 --> 00:03:01,750 and is guided into a crash barrier by a slipper in sliding contact with a rail 134 00:03:01,750 --> 00:03:01,760 slipper in sliding contact with a rail 135 00:03:01,760 --> 00:03:03,910 slipper in sliding contact with a rail this barrier is composed of an abutment 136 00:03:03,910 --> 00:03:03,920 this barrier is composed of an abutment 137 00:03:03,920 --> 00:03:07,350 this barrier is composed of an abutment in the path of each landing gear wheel 138 00:03:07,350 --> 00:03:07,360 in the path of each landing gear wheel 139 00:03:07,360 --> 00:03:09,509 in the path of each landing gear wheel the abutment strip the landing gear from 140 00:03:09,509 --> 00:03:09,519 the abutment strip the landing gear from 141 00:03:09,519 --> 00:03:11,430 the abutment strip the landing gear from the airplane 142 00:03:11,430 --> 00:03:11,440 the airplane 143 00:03:11,440 --> 00:03:13,350 the airplane if propellers strike the abutment at 144 00:03:13,350 --> 00:03:13,360 if propellers strike the abutment at 145 00:03:13,360 --> 00:03:15,830 if propellers strike the abutment at full engine power to produce extensive 146 00:03:15,830 --> 00:03:15,840 full engine power to produce extensive 147 00:03:15,840 --> 00:03:18,390 full engine power to produce extensive damage to the engine the cell 148 00:03:18,390 --> 00:03:18,400 damage to the engine the cell 149 00:03:18,400 --> 00:03:20,390 damage to the engine the cell the pair of poles on each side of the 150 00:03:20,390 --> 00:03:20,400 the pair of poles on each side of the 151 00:03:20,400 --> 00:03:22,949 the pair of poles on each side of the abutment cut into the wing fuel tanks 152 00:03:22,949 --> 00:03:22,959 abutment cut into the wing fuel tanks 153 00:03:22,959 --> 00:03:25,110 abutment cut into the wing fuel tanks causing spillage of the fuel at the 154 00:03:25,110 --> 00:03:25,120 causing spillage of the fuel at the 155 00:03:25,120 --> 00:03:27,110 causing spillage of the fuel at the moment of crash impact the airplane is 156 00:03:27,110 --> 00:03:27,120 moment of crash impact the airplane is 157 00:03:27,120 --> 00:03:29,509 moment of crash impact the airplane is moving at about 90 miles an hour the 158 00:03:29,509 --> 00:03:29,519 moving at about 90 miles an hour the 159 00:03:29,519 --> 00:03:31,430 moving at about 90 miles an hour the airplane carries a thousand gallons of 160 00:03:31,430 --> 00:03:31,440 airplane carries a thousand gallons of 161 00:03:31,440 --> 00:03:33,270 airplane carries a thousand gallons of fuel in the tanks outboard of the 162 00:03:33,270 --> 00:03:33,280 fuel in the tanks outboard of the 163 00:03:33,280 --> 00:03:36,070 fuel in the tanks outboard of the nacelles the fuel is sometimes dyed red 164 00:03:36,070 --> 00:03:36,080 nacelles the fuel is sometimes dyed red 165 00:03:36,080 --> 00:03:45,589 nacelles the fuel is sometimes dyed red for photographic purposes 166 00:03:45,589 --> 00:03:45,599 167 00:03:45,599 --> 00:03:47,430 a detailed description of the method of 168 00:03:47,430 --> 00:03:47,440 a detailed description of the method of 169 00:03:47,440 --> 00:03:49,430 a detailed description of the method of conducting these crashes was published 170 00:03:49,430 --> 00:03:49,440 conducting these crashes was published 171 00:03:49,440 --> 00:03:52,149 conducting these crashes was published in the naca research memorandum entitled 172 00:03:52,149 --> 00:03:52,159 in the naca research memorandum entitled 173 00:03:52,159 --> 00:03:53,750 in the naca research memorandum entitled facilities and methods used in 174 00:03:53,750 --> 00:03:53,760 facilities and methods used in 175 00:03:53,760 --> 00:03:56,070 facilities and methods used in full-scale airplane crash fire 176 00:03:56,070 --> 00:03:56,080 full-scale airplane crash fire 177 00:03:56,080 --> 00:03:59,030 full-scale airplane crash fire investigation 178 00:03:59,030 --> 00:03:59,040 179 00:03:59,040 --> 00:04:01,509 to understand how crash fires begin it 180 00:04:01,509 --> 00:04:01,519 to understand how crash fires begin it 181 00:04:01,519 --> 00:04:03,429 to understand how crash fires begin it is necessary to learn where and when 182 00:04:03,429 --> 00:04:03,439 is necessary to learn where and when 183 00:04:03,439 --> 00:04:05,509 is necessary to learn where and when ignition sources exist and how the 184 00:04:05,509 --> 00:04:05,519 ignition sources exist and how the 185 00:04:05,519 --> 00:04:07,509 ignition sources exist and how the combustibles move from the spillage 186 00:04:07,509 --> 00:04:07,519 combustibles move from the spillage 187 00:04:07,519 --> 00:04:09,589 combustibles move from the spillage zones to the ignition sources while 188 00:04:09,589 --> 00:04:09,599 zones to the ignition sources while 189 00:04:09,599 --> 00:04:11,910 zones to the ignition sources while these sources are still potent many 190 00:04:11,910 --> 00:04:11,920 these sources are still potent many 191 00:04:11,920 --> 00:04:13,509 these sources are still potent many ignition sources are carried on the 192 00:04:13,509 --> 00:04:13,519 ignition sources are carried on the 193 00:04:13,519 --> 00:04:15,670 ignition sources are carried on the airplane others are generated in the 194 00:04:15,670 --> 00:04:15,680 airplane others are generated in the 195 00:04:15,680 --> 00:04:17,110 airplane others are generated in the crash area 196 00:04:17,110 --> 00:04:17,120 crash area 197 00:04:17,120 --> 00:04:19,030 crash area a large number of ignition sources are 198 00:04:19,030 --> 00:04:19,040 a large number of ignition sources are 199 00:04:19,040 --> 00:04:21,189 a large number of ignition sources are located in the engine nacelle which 200 00:04:21,189 --> 00:04:21,199 located in the engine nacelle which 201 00:04:21,199 --> 00:04:23,590 located in the engine nacelle which contains the engine and hot metal parts 202 00:04:23,590 --> 00:04:23,600 contains the engine and hot metal parts 203 00:04:23,600 --> 00:04:25,590 contains the engine and hot metal parts of the exhaust system 204 00:04:25,590 --> 00:04:25,600 of the exhaust system 205 00:04:25,600 --> 00:04:27,590 of the exhaust system flames appear at the engine intake in 206 00:04:27,590 --> 00:04:27,600 flames appear at the engine intake in 207 00:04:27,600 --> 00:04:30,469 flames appear at the engine intake in the familiar backfire 208 00:04:30,469 --> 00:04:30,479 the familiar backfire 209 00:04:30,479 --> 00:04:32,710 the familiar backfire likewise flames appear at the exhaust 210 00:04:32,710 --> 00:04:32,720 likewise flames appear at the exhaust 211 00:04:32,720 --> 00:04:36,390 likewise flames appear at the exhaust outlet 212 00:04:36,390 --> 00:04:36,400 213 00:04:36,400 --> 00:04:38,070 the electrical system of the airplane 214 00:04:38,070 --> 00:04:38,080 the electrical system of the airplane 215 00:04:38,080 --> 00:04:40,070 the electrical system of the airplane represents the most widely distributed 216 00:04:40,070 --> 00:04:40,080 represents the most widely distributed 217 00:04:40,080 --> 00:04:42,230 represents the most widely distributed ignition source it extends from the 218 00:04:42,230 --> 00:04:42,240 ignition source it extends from the 219 00:04:42,240 --> 00:04:44,790 ignition source it extends from the nacelles into the wings to power fuel 220 00:04:44,790 --> 00:04:44,800 nacelles into the wings to power fuel 221 00:04:44,800 --> 00:04:47,270 nacelles into the wings to power fuel pumps and lights into the fuselage for 222 00:04:47,270 --> 00:04:47,280 pumps and lights into the fuselage for 223 00:04:47,280 --> 00:04:49,270 pumps and lights into the fuselage for lights navigational instruments and 224 00:04:49,270 --> 00:04:49,280 lights navigational instruments and 225 00:04:49,280 --> 00:04:51,830 lights navigational instruments and airplane controls 226 00:04:51,830 --> 00:04:51,840 airplane controls 227 00:04:51,840 --> 00:04:53,749 airplane controls of the combustibles carried in an 228 00:04:53,749 --> 00:04:53,759 of the combustibles carried in an 229 00:04:53,759 --> 00:04:55,990 of the combustibles carried in an airplane only those in liquid form are 230 00:04:55,990 --> 00:04:56,000 airplane only those in liquid form are 231 00:04:56,000 --> 00:04:58,230 airplane only those in liquid form are likely to contact ignition sources in a 232 00:04:58,230 --> 00:04:58,240 likely to contact ignition sources in a 233 00:04:58,240 --> 00:05:02,790 likely to contact ignition sources in a crash these combustibles are fuel 234 00:05:02,790 --> 00:05:02,800 235 00:05:02,800 --> 00:05:05,430 hydraulic fluid 236 00:05:05,430 --> 00:05:05,440 hydraulic fluid 237 00:05:05,440 --> 00:05:09,749 hydraulic fluid lubricating oil and alcohol 238 00:05:09,749 --> 00:05:09,759 lubricating oil and alcohol 239 00:05:09,759 --> 00:05:12,150 lubricating oil and alcohol the crash fire threatens human survival 240 00:05:12,150 --> 00:05:12,160 the crash fire threatens human survival 241 00:05:12,160 --> 00:05:14,230 the crash fire threatens human survival only when the fuel becomes involved in 242 00:05:14,230 --> 00:05:14,240 only when the fuel becomes involved in 243 00:05:14,240 --> 00:05:16,230 only when the fuel becomes involved in the fire because the other combustibles 244 00:05:16,230 --> 00:05:16,240 the fire because the other combustibles 245 00:05:16,240 --> 00:05:18,710 the fire because the other combustibles are present in small quantities however 246 00:05:18,710 --> 00:05:18,720 are present in small quantities however 247 00:05:18,720 --> 00:05:20,870 are present in small quantities however the other liquid combustibles may be the 248 00:05:20,870 --> 00:05:20,880 the other liquid combustibles may be the 249 00:05:20,880 --> 00:05:23,670 the other liquid combustibles may be the first to ignite and in turn set fire to 250 00:05:23,670 --> 00:05:23,680 first to ignite and in turn set fire to 251 00:05:23,680 --> 00:05:25,270 first to ignite and in turn set fire to the fuel 252 00:05:25,270 --> 00:05:25,280 the fuel 253 00:05:25,280 --> 00:05:27,270 the fuel in the conventional airplane most of the 254 00:05:27,270 --> 00:05:27,280 in the conventional airplane most of the 255 00:05:27,280 --> 00:05:29,990 in the conventional airplane most of the fuel is stored in wing tanks the tanks 256 00:05:29,990 --> 00:05:30,000 fuel is stored in wing tanks the tanks 257 00:05:30,000 --> 00:05:32,469 fuel is stored in wing tanks the tanks are interconnected by pipes so that fuel 258 00:05:32,469 --> 00:05:32,479 are interconnected by pipes so that fuel 259 00:05:32,479 --> 00:05:34,790 are interconnected by pipes so that fuel from any tank can serve all the engines 260 00:05:34,790 --> 00:05:34,800 from any tank can serve all the engines 261 00:05:34,800 --> 00:05:36,550 from any tank can serve all the engines through main lines which run to the 262 00:05:36,550 --> 00:05:36,560 through main lines which run to the 263 00:05:36,560 --> 00:05:38,469 through main lines which run to the engine carburetor 264 00:05:38,469 --> 00:05:38,479 engine carburetor 265 00:05:38,479 --> 00:05:40,870 engine carburetor in a crash fuel often is spilled in 266 00:05:40,870 --> 00:05:40,880 in a crash fuel often is spilled in 267 00:05:40,880 --> 00:05:43,749 in a crash fuel often is spilled in liquid form from broken fuel lines 268 00:05:43,749 --> 00:05:43,759 liquid form from broken fuel lines 269 00:05:43,759 --> 00:05:45,749 liquid form from broken fuel lines likewise liquid spillage occurs from 270 00:05:45,749 --> 00:05:45,759 likewise liquid spillage occurs from 271 00:05:45,759 --> 00:05:47,350 likewise liquid spillage occurs from damaged tanks 272 00:05:47,350 --> 00:05:47,360 damaged tanks 273 00:05:47,360 --> 00:05:49,909 damaged tanks pre-mixed fuel vapor and air spills from 274 00:05:49,909 --> 00:05:49,919 pre-mixed fuel vapor and air spills from 275 00:05:49,919 --> 00:05:52,550 pre-mixed fuel vapor and air spills from the damaged engine induction system and 276 00:05:52,550 --> 00:05:52,560 the damaged engine induction system and 277 00:05:52,560 --> 00:05:55,189 the damaged engine induction system and a combustible fuel mist sometimes forms 278 00:05:55,189 --> 00:05:55,199 a combustible fuel mist sometimes forms 279 00:05:55,199 --> 00:05:57,430 a combustible fuel mist sometimes forms around the airplane the airplanes were 280 00:05:57,430 --> 00:05:57,440 around the airplane the airplanes were 281 00:05:57,440 --> 00:05:59,749 around the airplane the airplanes were crashed in ways that resulted in all 282 00:05:59,749 --> 00:05:59,759 crashed in ways that resulted in all 283 00:05:59,759 --> 00:06:02,950 crashed in ways that resulted in all these forms of fuel spillage 284 00:06:02,950 --> 00:06:02,960 these forms of fuel spillage 285 00:06:02,960 --> 00:06:05,110 these forms of fuel spillage in studying how the fires are started it 286 00:06:05,110 --> 00:06:05,120 in studying how the fires are started it 287 00:06:05,120 --> 00:06:06,870 in studying how the fires are started it is necessary to consider the ignition 288 00:06:06,870 --> 00:06:06,880 is necessary to consider the ignition 289 00:06:06,880 --> 00:06:09,590 is necessary to consider the ignition sources along with the fuel spillage the 290 00:06:09,590 --> 00:06:09,600 sources along with the fuel spillage the 291 00:06:09,600 --> 00:06:11,110 sources along with the fuel spillage the following discussion will take up the 292 00:06:11,110 --> 00:06:11,120 following discussion will take up the 293 00:06:11,120 --> 00:06:13,270 following discussion will take up the various forms of fuel spillage and how 294 00:06:13,270 --> 00:06:13,280 various forms of fuel spillage and how 295 00:06:13,280 --> 00:06:15,830 various forms of fuel spillage and how the fuel moves to the ignition sources 296 00:06:15,830 --> 00:06:15,840 the fuel moves to the ignition sources 297 00:06:15,840 --> 00:06:17,430 the fuel moves to the ignition sources the characteristics of the ignition 298 00:06:17,430 --> 00:06:17,440 the characteristics of the ignition 299 00:06:17,440 --> 00:06:19,270 the characteristics of the ignition sources will be discussed at the same 300 00:06:19,270 --> 00:06:19,280 sources will be discussed at the same 301 00:06:19,280 --> 00:06:23,990 sources will be discussed at the same time 302 00:06:23,990 --> 00:06:24,000 303 00:06:24,000 --> 00:06:26,309 because the fuel in the mist form played 304 00:06:26,309 --> 00:06:26,319 because the fuel in the mist form played 305 00:06:26,319 --> 00:06:28,150 because the fuel in the mist form played such an important role in the crash 306 00:06:28,150 --> 00:06:28,160 such an important role in the crash 307 00:06:28,160 --> 00:06:30,550 such an important role in the crash fires experienced in this study fires 308 00:06:30,550 --> 00:06:30,560 fires experienced in this study fires 309 00:06:30,560 --> 00:06:32,710 fires experienced in this study fires involving fuel mist will be discussed 310 00:06:32,710 --> 00:06:32,720 involving fuel mist will be discussed 311 00:06:32,720 --> 00:06:35,350 involving fuel mist will be discussed first when the liquid fuel spills into 312 00:06:35,350 --> 00:06:35,360 first when the liquid fuel spills into 313 00:06:35,360 --> 00:06:37,189 first when the liquid fuel spills into the open air while the airplane is in 314 00:06:37,189 --> 00:06:37,199 the open air while the airplane is in 315 00:06:37,199 --> 00:06:42,390 the open air while the airplane is in motion it is atomized into a mist 316 00:06:42,390 --> 00:06:42,400 317 00:06:42,400 --> 00:06:44,710 in this scene shown at one-fifth normal 318 00:06:44,710 --> 00:06:44,720 in this scene shown at one-fifth normal 319 00:06:44,720 --> 00:06:47,029 in this scene shown at one-fifth normal speed watch how the fuel dyed red for 320 00:06:47,029 --> 00:06:47,039 speed watch how the fuel dyed red for 321 00:06:47,039 --> 00:06:49,350 speed watch how the fuel dyed red for visual clarity develops into mist during 322 00:06:49,350 --> 00:06:49,360 visual clarity develops into mist during 323 00:06:49,360 --> 00:06:51,990 visual clarity develops into mist during a crash as the fuel pours from the tanks 324 00:06:51,990 --> 00:06:52,000 a crash as the fuel pours from the tanks 325 00:06:52,000 --> 00:06:54,230 a crash as the fuel pours from the tanks breached by the poles at the barrier the 326 00:06:54,230 --> 00:06:54,240 breached by the poles at the barrier the 327 00:06:54,240 --> 00:06:56,870 breached by the poles at the barrier the fuel is atomized to mist a part of which 328 00:06:56,870 --> 00:06:56,880 fuel is atomized to mist a part of which 329 00:06:56,880 --> 00:06:58,950 fuel is atomized to mist a part of which remains suspended in the air 330 00:06:58,950 --> 00:06:58,960 remains suspended in the air 331 00:06:58,960 --> 00:07:00,870 remains suspended in the air the plume of the fuel mist streams 332 00:07:00,870 --> 00:07:00,880 the plume of the fuel mist streams 333 00:07:00,880 --> 00:07:02,710 the plume of the fuel mist streams directly rearward from the break in the 334 00:07:02,710 --> 00:07:02,720 directly rearward from the break in the 335 00:07:02,720 --> 00:07:04,870 directly rearward from the break in the tanks if the damage to the airplane in 336 00:07:04,870 --> 00:07:04,880 tanks if the damage to the airplane in 337 00:07:04,880 --> 00:07:06,710 tanks if the damage to the airplane in the crash results in only moderate 338 00:07:06,710 --> 00:07:06,720 the crash results in only moderate 339 00:07:06,720 --> 00:07:09,270 the crash results in only moderate deceleration and the airplane continues 340 00:07:09,270 --> 00:07:09,280 deceleration and the airplane continues 341 00:07:09,280 --> 00:07:11,510 deceleration and the airplane continues forward at high speed when the airplane 342 00:07:11,510 --> 00:07:11,520 forward at high speed when the airplane 343 00:07:11,520 --> 00:07:12,950 forward at high speed when the airplane moves at low speed with high 344 00:07:12,950 --> 00:07:12,960 moves at low speed with high 345 00:07:12,960 --> 00:07:15,670 moves at low speed with high deceleration the fuel surges forward out 346 00:07:15,670 --> 00:07:15,680 deceleration the fuel surges forward out 347 00:07:15,680 --> 00:07:17,909 deceleration the fuel surges forward out of the break in the tank this results in 348 00:07:17,909 --> 00:07:17,919 of the break in the tank this results in 349 00:07:17,919 --> 00:07:20,150 of the break in the tank this results in a broad fuel mist pattern in the forward 350 00:07:20,150 --> 00:07:20,160 a broad fuel mist pattern in the forward 351 00:07:20,160 --> 00:07:22,309 a broad fuel mist pattern in the forward portions of the airplane under such 352 00:07:22,309 --> 00:07:22,319 portions of the airplane under such 353 00:07:22,319 --> 00:07:24,309 portions of the airplane under such conditions contact between fuel and 354 00:07:24,309 --> 00:07:24,319 conditions contact between fuel and 355 00:07:24,319 --> 00:07:26,230 conditions contact between fuel and ignition sources at the nacelle is 356 00:07:26,230 --> 00:07:26,240 ignition sources at the nacelle is 357 00:07:26,240 --> 00:07:28,550 ignition sources at the nacelle is likely 358 00:07:28,550 --> 00:07:28,560 likely 359 00:07:28,560 --> 00:07:30,150 likely now watch in the next crash the 360 00:07:30,150 --> 00:07:30,160 now watch in the next crash the 361 00:07:30,160 --> 00:07:32,070 now watch in the next crash the transition of the fuel mist development 362 00:07:32,070 --> 00:07:32,080 transition of the fuel mist development 363 00:07:32,080 --> 00:07:34,230 transition of the fuel mist development from the high speed low deceleration 364 00:07:34,230 --> 00:07:34,240 from the high speed low deceleration 365 00:07:34,240 --> 00:07:35,990 from the high speed low deceleration pattern to the low speed high 366 00:07:35,990 --> 00:07:36,000 pattern to the low speed high 367 00:07:36,000 --> 00:07:37,990 pattern to the low speed high deceleration pattern 368 00:07:37,990 --> 00:07:38,000 deceleration pattern 369 00:07:38,000 --> 00:07:39,830 deceleration pattern here comes the airplane at about 90 370 00:07:39,830 --> 00:07:39,840 here comes the airplane at about 90 371 00:07:39,840 --> 00:07:42,150 here comes the airplane at about 90 miles an hour the motion is reduced to 372 00:07:42,150 --> 00:07:42,160 miles an hour the motion is reduced to 373 00:07:42,160 --> 00:07:44,710 miles an hour the motion is reduced to one-fifth normal speed the impact of the 374 00:07:44,710 --> 00:07:44,720 one-fifth normal speed the impact of the 375 00:07:44,720 --> 00:07:46,870 one-fifth normal speed the impact of the barrier will produce momentary moderate 376 00:07:46,870 --> 00:07:46,880 barrier will produce momentary moderate 377 00:07:46,880 --> 00:07:49,350 barrier will produce momentary moderate airplane decelerations observe that the 378 00:07:49,350 --> 00:07:49,360 airplane decelerations observe that the 379 00:07:49,360 --> 00:07:51,990 airplane decelerations observe that the fuel died red streams directly back from 380 00:07:51,990 --> 00:07:52,000 fuel died red streams directly back from 381 00:07:52,000 --> 00:07:53,909 fuel died red streams directly back from the leading edge when the airplane 382 00:07:53,909 --> 00:07:53,919 the leading edge when the airplane 383 00:07:53,919 --> 00:07:55,189 the leading edge when the airplane strikes the ground with high 384 00:07:55,189 --> 00:07:55,199 strikes the ground with high 385 00:07:55,199 --> 00:07:57,909 strikes the ground with high deceleration the fuel mist develops well 386 00:07:57,909 --> 00:07:57,919 deceleration the fuel mist develops well 387 00:07:57,919 --> 00:07:59,589 deceleration the fuel mist develops well forward of the wing leading edge and 388 00:07:59,589 --> 00:07:59,599 forward of the wing leading edge and 389 00:07:59,599 --> 00:08:02,869 forward of the wing leading edge and spreads span wise as the airplane slows 390 00:08:02,869 --> 00:08:02,879 spreads span wise as the airplane slows 391 00:08:02,879 --> 00:08:05,270 spreads span wise as the airplane slows in view of these effects the fuel mist 392 00:08:05,270 --> 00:08:05,280 in view of these effects the fuel mist 393 00:08:05,280 --> 00:08:07,270 in view of these effects the fuel mist can be expected to contact an ignition 394 00:08:07,270 --> 00:08:07,280 can be expected to contact an ignition 395 00:08:07,280 --> 00:08:09,350 can be expected to contact an ignition source which lies span wise from the 396 00:08:09,350 --> 00:08:09,360 source which lies span wise from the 397 00:08:09,360 --> 00:08:11,430 source which lies span wise from the point of fuel spillage as the airplane 398 00:08:11,430 --> 00:08:11,440 point of fuel spillage as the airplane 399 00:08:11,440 --> 00:08:12,869 point of fuel spillage as the airplane slows down 400 00:08:12,869 --> 00:08:12,879 slows down 401 00:08:12,879 --> 00:08:14,550 slows down in the motion pictures of the crash 402 00:08:14,550 --> 00:08:14,560 in the motion pictures of the crash 403 00:08:14,560 --> 00:08:16,550 in the motion pictures of the crash illustrating this effect look for a 404 00:08:16,550 --> 00:08:16,560 illustrating this effect look for a 405 00:08:16,560 --> 00:08:18,469 illustrating this effect look for a continuing series of flames at the 406 00:08:18,469 --> 00:08:18,479 continuing series of flames at the 407 00:08:18,479 --> 00:08:20,950 continuing series of flames at the engine exhaust following crash impacted 408 00:08:20,950 --> 00:08:20,960 engine exhaust following crash impacted 409 00:08:20,960 --> 00:08:23,189 engine exhaust following crash impacted the barrier as the airplane skids along 410 00:08:23,189 --> 00:08:23,199 the barrier as the airplane skids along 411 00:08:23,199 --> 00:08:24,790 the barrier as the airplane skids along the ground the fuel spilling from the 412 00:08:24,790 --> 00:08:24,800 the ground the fuel spilling from the 413 00:08:24,800 --> 00:08:27,350 the ground the fuel spilling from the wing at this location moves span wise in 414 00:08:27,350 --> 00:08:27,360 wing at this location moves span wise in 415 00:08:27,360 --> 00:08:30,070 wing at this location moves span wise in mist form until it reaches an exhaust 416 00:08:30,070 --> 00:08:30,080 mist form until it reaches an exhaust 417 00:08:30,080 --> 00:08:39,509 mist form until it reaches an exhaust flame just before the airplane stops 418 00:08:39,509 --> 00:08:39,519 419 00:08:39,519 --> 00:08:41,509 now let us observe this method of fuel 420 00:08:41,509 --> 00:08:41,519 now let us observe this method of fuel 421 00:08:41,519 --> 00:08:43,750 now let us observe this method of fuel movement to the engine tailpipe the 422 00:08:43,750 --> 00:08:43,760 movement to the engine tailpipe the 423 00:08:43,760 --> 00:08:46,070 movement to the engine tailpipe the action here is reduced to one-fifth 424 00:08:46,070 --> 00:08:46,080 action here is reduced to one-fifth 425 00:08:46,080 --> 00:08:52,829 action here is reduced to one-fifth normal 426 00:08:52,829 --> 00:08:52,839 427 00:08:52,839 --> 00:08:56,150 speed notice the flames at the tailpipe 428 00:08:56,150 --> 00:08:56,160 speed notice the flames at the tailpipe 429 00:08:56,160 --> 00:08:58,470 speed notice the flames at the tailpipe contact of the fuel mist with an exhaust 430 00:08:58,470 --> 00:08:58,480 contact of the fuel mist with an exhaust 431 00:08:58,480 --> 00:09:00,870 contact of the fuel mist with an exhaust flame occurs just as the airplane comes 432 00:09:00,870 --> 00:09:00,880 flame occurs just as the airplane comes 433 00:09:00,880 --> 00:09:10,710 flame occurs just as the airplane comes to a stop 434 00:09:10,710 --> 00:09:10,720 435 00:09:10,720 --> 00:09:12,470 ignition of the fuel mist occurred on 436 00:09:12,470 --> 00:09:12,480 ignition of the fuel mist occurred on 437 00:09:12,480 --> 00:09:14,630 ignition of the fuel mist occurred on the same airplane on the hot exhaust 438 00:09:14,630 --> 00:09:14,640 the same airplane on the hot exhaust 439 00:09:14,640 --> 00:09:16,630 the same airplane on the hot exhaust collector ring of the engine on your 440 00:09:16,630 --> 00:09:16,640 collector ring of the engine on your 441 00:09:16,640 --> 00:09:18,550 collector ring of the engine on your left at this location 442 00:09:18,550 --> 00:09:18,560 left at this location 443 00:09:18,560 --> 00:09:20,630 left at this location under impact at the barrier the engine 444 00:09:20,630 --> 00:09:20,640 under impact at the barrier the engine 445 00:09:20,640 --> 00:09:22,870 under impact at the barrier the engine the cell breaks down and exposes the 446 00:09:22,870 --> 00:09:22,880 the cell breaks down and exposes the 447 00:09:22,880 --> 00:09:25,430 the cell breaks down and exposes the exhaust collector ring as the airplane 448 00:09:25,430 --> 00:09:25,440 exhaust collector ring as the airplane 449 00:09:25,440 --> 00:09:28,070 exhaust collector ring as the airplane slows the fuel mist moves span wise and 450 00:09:28,070 --> 00:09:28,080 slows the fuel mist moves span wise and 451 00:09:28,080 --> 00:09:37,829 slows the fuel mist moves span wise and forward to the exposed collector ring 452 00:09:37,829 --> 00:09:37,839 453 00:09:37,839 --> 00:09:39,829 here comes the same airplane watch how 454 00:09:39,829 --> 00:09:39,839 here comes the same airplane watch how 455 00:09:39,839 --> 00:09:42,150 here comes the same airplane watch how the nacelle on your left tips downward 456 00:09:42,150 --> 00:09:42,160 the nacelle on your left tips downward 457 00:09:42,160 --> 00:09:43,829 the nacelle on your left tips downward as the propeller hits the barrier 458 00:09:43,829 --> 00:09:43,839 as the propeller hits the barrier 459 00:09:43,839 --> 00:09:46,150 as the propeller hits the barrier exposing the exhaust collector ring the 460 00:09:46,150 --> 00:09:46,160 exposing the exhaust collector ring the 461 00:09:46,160 --> 00:09:47,990 exposing the exhaust collector ring the flame first appears at the top of the 462 00:09:47,990 --> 00:09:48,000 flame first appears at the top of the 463 00:09:48,000 --> 00:09:49,990 flame first appears at the top of the nacelle where the fuel mist contacts the 464 00:09:49,990 --> 00:09:50,000 nacelle where the fuel mist contacts the 465 00:09:50,000 --> 00:09:56,870 nacelle where the fuel mist contacts the exhaust collector ring 466 00:09:56,870 --> 00:09:56,880 467 00:09:56,880 --> 00:09:58,790 in the time between initial fuel 468 00:09:58,790 --> 00:09:58,800 in the time between initial fuel 469 00:09:58,800 --> 00:10:01,590 in the time between initial fuel spillage and ignition and explosive fuel 470 00:10:01,590 --> 00:10:01,600 spillage and ignition and explosive fuel 471 00:10:01,600 --> 00:10:03,829 spillage and ignition and explosive fuel air mixture accumulated in the wing 472 00:10:03,829 --> 00:10:03,839 air mixture accumulated in the wing 473 00:10:03,839 --> 00:10:05,829 air mixture accumulated in the wing explosion of the mixture produced this 474 00:10:05,829 --> 00:10:05,839 explosion of the mixture produced this 475 00:10:05,839 --> 00:10:11,030 explosion of the mixture produced this distribution of flaming fuel 476 00:10:11,030 --> 00:10:11,040 477 00:10:11,040 --> 00:10:13,509 fuels of low volatility and mist form 478 00:10:13,509 --> 00:10:13,519 fuels of low volatility and mist form 479 00:10:13,519 --> 00:10:15,509 fuels of low volatility and mist form ignite readily in spite of the fact they 480 00:10:15,509 --> 00:10:15,519 ignite readily in spite of the fact they 481 00:10:15,519 --> 00:10:17,430 ignite readily in spite of the fact they are safe in liquid form in the presence 482 00:10:17,430 --> 00:10:17,440 are safe in liquid form in the presence 483 00:10:17,440 --> 00:10:20,310 are safe in liquid form in the presence of open flames a wick saturated with 484 00:10:20,310 --> 00:10:20,320 of open flames a wick saturated with 485 00:10:20,320 --> 00:10:22,630 of open flames a wick saturated with this fuel can be ignited by the steady 486 00:10:22,630 --> 00:10:22,640 this fuel can be ignited by the steady 487 00:10:22,640 --> 00:10:25,030 this fuel can be ignited by the steady application of a flame the lighted match 488 00:10:25,030 --> 00:10:25,040 application of a flame the lighted match 489 00:10:25,040 --> 00:10:26,710 application of a flame the lighted match held above the surface of this low 490 00:10:26,710 --> 00:10:26,720 held above the surface of this low 491 00:10:26,720 --> 00:10:34,630 held above the surface of this low volatility fuel produces no ignition 492 00:10:34,630 --> 00:10:34,640 493 00:10:34,640 --> 00:10:36,790 observe in the next crash the ignition 494 00:10:36,790 --> 00:10:36,800 observe in the next crash the ignition 495 00:10:36,800 --> 00:10:39,430 observe in the next crash the ignition of the mist of low volatility fuel by a 496 00:10:39,430 --> 00:10:39,440 of the mist of low volatility fuel by a 497 00:10:39,440 --> 00:10:41,030 of the mist of low volatility fuel by a tailpipe flame 498 00:10:41,030 --> 00:10:41,040 tailpipe flame 499 00:10:41,040 --> 00:10:43,430 tailpipe flame note also the backfire flame at the 500 00:10:43,430 --> 00:10:43,440 note also the backfire flame at the 501 00:10:43,440 --> 00:10:45,750 note also the backfire flame at the engine inlet that follows the main fuel 502 00:10:45,750 --> 00:10:45,760 engine inlet that follows the main fuel 503 00:10:45,760 --> 00:10:48,150 engine inlet that follows the main fuel ignition 504 00:10:48,150 --> 00:10:48,160 ignition 505 00:10:48,160 --> 00:10:50,150 ignition the tanks of the oncoming plane are 506 00:10:50,150 --> 00:10:50,160 the tanks of the oncoming plane are 507 00:10:50,160 --> 00:10:52,630 the tanks of the oncoming plane are filled with low volatility fuel this 508 00:10:52,630 --> 00:10:52,640 filled with low volatility fuel this 509 00:10:52,640 --> 00:10:54,870 filled with low volatility fuel this action is reduced to one-fifth normal 510 00:10:54,870 --> 00:10:54,880 action is reduced to one-fifth normal 511 00:10:54,880 --> 00:10:59,509 action is reduced to one-fifth normal speed 512 00:10:59,509 --> 00:10:59,519 513 00:10:59,519 --> 00:11:01,430 here is the ignition by the tailpipe 514 00:11:01,430 --> 00:11:01,440 here is the ignition by the tailpipe 515 00:11:01,440 --> 00:11:03,910 here is the ignition by the tailpipe flame 516 00:11:03,910 --> 00:11:03,920 517 00:11:03,920 --> 00:11:06,230 now watch for the backfire at the engine 518 00:11:06,230 --> 00:11:06,240 now watch for the backfire at the engine 519 00:11:06,240 --> 00:11:20,710 now watch for the backfire at the engine inlet 520 00:11:20,710 --> 00:11:20,720 521 00:11:20,720 --> 00:11:22,630 this aerial view of the crash with the 522 00:11:22,630 --> 00:11:22,640 this aerial view of the crash with the 523 00:11:22,640 --> 00:11:24,870 this aerial view of the crash with the action slowed to one third normal speed 524 00:11:24,870 --> 00:11:24,880 action slowed to one third normal speed 525 00:11:24,880 --> 00:11:26,630 action slowed to one third normal speed shows the flames traveling through the 526 00:11:26,630 --> 00:11:26,640 shows the flames traveling through the 527 00:11:26,640 --> 00:11:28,710 shows the flames traveling through the fuel mist at a rate comparable to that 528 00:11:28,710 --> 00:11:28,720 fuel mist at a rate comparable to that 529 00:11:28,720 --> 00:11:37,910 fuel mist at a rate comparable to that of gasoline 530 00:11:37,910 --> 00:11:37,920 531 00:11:37,920 --> 00:11:39,829 the flames at the engine exhaust that 532 00:11:39,829 --> 00:11:39,839 the flames at the engine exhaust that 533 00:11:39,839 --> 00:11:41,990 the flames at the engine exhaust that were observed igniting these mists may 534 00:11:41,990 --> 00:11:42,000 were observed igniting these mists may 535 00:11:42,000 --> 00:11:43,910 were observed igniting these mists may occur in a crash as long as the engine 536 00:11:43,910 --> 00:11:43,920 occur in a crash as long as the engine 537 00:11:43,920 --> 00:11:46,790 occur in a crash as long as the engine is rotating and drawing fuel even impact 538 00:11:46,790 --> 00:11:46,800 is rotating and drawing fuel even impact 539 00:11:46,800 --> 00:11:48,550 is rotating and drawing fuel even impact of the propellers with an obstacle does 540 00:11:48,550 --> 00:11:48,560 of the propellers with an obstacle does 541 00:11:48,560 --> 00:11:50,310 of the propellers with an obstacle does not ensure that the engine will stop 542 00:11:50,310 --> 00:11:50,320 not ensure that the engine will stop 543 00:11:50,320 --> 00:11:56,550 not ensure that the engine will stop running 544 00:11:56,550 --> 00:11:56,560 545 00:11:56,560 --> 00:11:58,949 in this crash shown at normal speed the 546 00:11:58,949 --> 00:11:58,959 in this crash shown at normal speed the 547 00:11:58,959 --> 00:12:01,190 in this crash shown at normal speed the damaged engines continues to operate for 548 00:12:01,190 --> 00:12:01,200 damaged engines continues to operate for 549 00:12:01,200 --> 00:12:03,990 damaged engines continues to operate for several minutes after crash impact watch 550 00:12:03,990 --> 00:12:04,000 several minutes after crash impact watch 551 00:12:04,000 --> 00:12:06,389 several minutes after crash impact watch how the propellers now in slow rotation 552 00:12:06,389 --> 00:12:06,399 how the propellers now in slow rotation 553 00:12:06,399 --> 00:12:09,350 how the propellers now in slow rotation accelerate this alternation of slow and 554 00:12:09,350 --> 00:12:09,360 accelerate this alternation of slow and 555 00:12:09,360 --> 00:12:11,670 accelerate this alternation of slow and fast rotation continues through several 556 00:12:11,670 --> 00:12:11,680 fast rotation continues through several 557 00:12:11,680 --> 00:12:19,750 fast rotation continues through several cycles one of which is shown here 558 00:12:19,750 --> 00:12:19,760 559 00:12:19,760 --> 00:12:21,910 another ignition source in the engine 560 00:12:21,910 --> 00:12:21,920 another ignition source in the engine 561 00:12:21,920 --> 00:12:24,150 another ignition source in the engine cell which may ignite the fuel mist is 562 00:12:24,150 --> 00:12:24,160 cell which may ignite the fuel mist is 563 00:12:24,160 --> 00:12:26,230 cell which may ignite the fuel mist is provided by lubricating oil burning 564 00:12:26,230 --> 00:12:26,240 provided by lubricating oil burning 565 00:12:26,240 --> 00:12:28,230 provided by lubricating oil burning within the nacelle 566 00:12:28,230 --> 00:12:28,240 within the nacelle 567 00:12:28,240 --> 00:12:30,310 within the nacelle the next crash you will see shows how 568 00:12:30,310 --> 00:12:30,320 the next crash you will see shows how 569 00:12:30,320 --> 00:12:32,470 the next crash you will see shows how the lubricating oil can set fire to the 570 00:12:32,470 --> 00:12:32,480 the lubricating oil can set fire to the 571 00:12:32,480 --> 00:12:33,350 the lubricating oil can set fire to the fuel 572 00:12:33,350 --> 00:12:33,360 fuel 573 00:12:33,360 --> 00:12:35,590 fuel on the low wing airplane used in this 574 00:12:35,590 --> 00:12:35,600 on the low wing airplane used in this 575 00:12:35,600 --> 00:12:37,670 on the low wing airplane used in this crash the nacelle strike the ground when 576 00:12:37,670 --> 00:12:37,680 crash the nacelle strike the ground when 577 00:12:37,680 --> 00:12:40,389 crash the nacelle strike the ground when the landing gear is sheared off the oil 578 00:12:40,389 --> 00:12:40,399 the landing gear is sheared off the oil 579 00:12:40,399 --> 00:12:42,150 the landing gear is sheared off the oil cooler located at the bottom of the 580 00:12:42,150 --> 00:12:42,160 cooler located at the bottom of the 581 00:12:42,160 --> 00:12:44,150 cooler located at the bottom of the nacelle is ripped open when the cell 582 00:12:44,150 --> 00:12:44,160 nacelle is ripped open when the cell 583 00:12:44,160 --> 00:12:46,310 nacelle is ripped open when the cell strikes the ground the released oil is 584 00:12:46,310 --> 00:12:46,320 strikes the ground the released oil is 585 00:12:46,320 --> 00:12:48,470 strikes the ground the released oil is ignited on contact with the hot engine 586 00:12:48,470 --> 00:12:48,480 ignited on contact with the hot engine 587 00:12:48,480 --> 00:12:55,269 ignited on contact with the hot engine exhaust collector ring close by 588 00:12:55,269 --> 00:12:55,279 589 00:12:55,279 --> 00:12:57,190 now we shall see how this fire setting 590 00:12:57,190 --> 00:12:57,200 now we shall see how this fire setting 591 00:12:57,200 --> 00:12:59,350 now we shall see how this fire setting process acts in a crash of a low wing 592 00:12:59,350 --> 00:12:59,360 process acts in a crash of a low wing 593 00:12:59,360 --> 00:13:01,829 process acts in a crash of a low wing airplane having the nacelle arrangements 594 00:13:01,829 --> 00:13:01,839 airplane having the nacelle arrangements 595 00:13:01,839 --> 00:13:04,069 airplane having the nacelle arrangements shown previously the action is reduced 596 00:13:04,069 --> 00:13:04,079 shown previously the action is reduced 597 00:13:04,079 --> 00:13:06,389 shown previously the action is reduced to 1 12 normal speed 598 00:13:06,389 --> 00:13:06,399 to 1 12 normal speed 599 00:13:06,399 --> 00:13:08,710 to 1 12 normal speed after passing through the crash barrier 600 00:13:08,710 --> 00:13:08,720 after passing through the crash barrier 601 00:13:08,720 --> 00:13:10,629 after passing through the crash barrier the unsupported airplane strikes the 602 00:13:10,629 --> 00:13:10,639 the unsupported airplane strikes the 603 00:13:10,639 --> 00:13:13,030 the unsupported airplane strikes the ground the cells foremost causing the 604 00:13:13,030 --> 00:13:13,040 ground the cells foremost causing the 605 00:13:13,040 --> 00:13:15,350 ground the cells foremost causing the oil cooler in the nacelle to break back 606 00:13:15,350 --> 00:13:15,360 oil cooler in the nacelle to break back 607 00:13:15,360 --> 00:13:17,430 oil cooler in the nacelle to break back and release oil onto the hot exhaust 608 00:13:17,430 --> 00:13:17,440 and release oil onto the hot exhaust 609 00:13:17,440 --> 00:13:18,790 and release oil onto the hot exhaust collector ring 610 00:13:18,790 --> 00:13:18,800 collector ring 611 00:13:18,800 --> 00:13:21,190 collector ring now condensed oil vapor generated on the 612 00:13:21,190 --> 00:13:21,200 now condensed oil vapor generated on the 613 00:13:21,200 --> 00:13:23,670 now condensed oil vapor generated on the exhaust system can be seen issuing from 614 00:13:23,670 --> 00:13:23,680 exhaust system can be seen issuing from 615 00:13:23,680 --> 00:13:24,790 exhaust system can be seen issuing from the nacelle 616 00:13:24,790 --> 00:13:24,800 the nacelle 617 00:13:24,800 --> 00:13:27,030 the nacelle as the airplane slows the fuel spilling 618 00:13:27,030 --> 00:13:27,040 as the airplane slows the fuel spilling 619 00:13:27,040 --> 00:13:28,629 as the airplane slows the fuel spilling from the wing moves out ahead of the 620 00:13:28,629 --> 00:13:28,639 from the wing moves out ahead of the 621 00:13:28,639 --> 00:13:30,310 from the wing moves out ahead of the leading edge and spreads toward the 622 00:13:30,310 --> 00:13:30,320 leading edge and spreads toward the 623 00:13:30,320 --> 00:13:32,470 leading edge and spreads toward the nacelle 624 00:13:32,470 --> 00:13:32,480 nacelle 625 00:13:32,480 --> 00:13:34,870 nacelle two seconds after crash impact ignition 626 00:13:34,870 --> 00:13:34,880 two seconds after crash impact ignition 627 00:13:34,880 --> 00:13:36,710 two seconds after crash impact ignition of the oil is indicated by the fire 628 00:13:36,710 --> 00:13:36,720 of the oil is indicated by the fire 629 00:13:36,720 --> 00:13:39,190 of the oil is indicated by the fire detectors a marked increase in the rate 630 00:13:39,190 --> 00:13:39,200 detectors a marked increase in the rate 631 00:13:39,200 --> 00:13:41,030 detectors a marked increase in the rate of formation of oil vapors follows 632 00:13:41,030 --> 00:13:41,040 of formation of oil vapors follows 633 00:13:41,040 --> 00:13:43,590 of formation of oil vapors follows ignition of the oil 634 00:13:43,590 --> 00:13:43,600 ignition of the oil 635 00:13:43,600 --> 00:13:45,509 ignition of the oil three seconds after crash impact the 636 00:13:45,509 --> 00:13:45,519 three seconds after crash impact the 637 00:13:45,519 --> 00:13:47,910 three seconds after crash impact the entire engine exhaust collector ring is 638 00:13:47,910 --> 00:13:47,920 entire engine exhaust collector ring is 639 00:13:47,920 --> 00:13:49,670 entire engine exhaust collector ring is enveloped in fire 640 00:13:49,670 --> 00:13:49,680 enveloped in fire 641 00:13:49,680 --> 00:13:52,150 enveloped in fire as the airplane comes to a stop the fuel 642 00:13:52,150 --> 00:13:52,160 as the airplane comes to a stop the fuel 643 00:13:52,160 --> 00:13:54,389 as the airplane comes to a stop the fuel mist and oil vapors form a continuous 644 00:13:54,389 --> 00:13:54,399 mist and oil vapors form a continuous 645 00:13:54,399 --> 00:13:57,189 mist and oil vapors form a continuous combustible atmosphere in a cell oil 646 00:13:57,189 --> 00:13:57,199 combustible atmosphere in a cell oil 647 00:13:57,199 --> 00:13:59,189 combustible atmosphere in a cell oil fire spreading through the oil mist will 648 00:13:59,189 --> 00:13:59,199 fire spreading through the oil mist will 649 00:13:59,199 --> 00:14:01,269 fire spreading through the oil mist will now appear outside of the nacelle and 650 00:14:01,269 --> 00:14:01,279 now appear outside of the nacelle and 651 00:14:01,279 --> 00:14:03,350 now appear outside of the nacelle and move rapidly to the fuel 652 00:14:03,350 --> 00:14:03,360 move rapidly to the fuel 653 00:14:03,360 --> 00:14:05,189 move rapidly to the fuel watch how the fire moves to the breach 654 00:14:05,189 --> 00:14:05,199 watch how the fire moves to the breach 655 00:14:05,199 --> 00:14:07,110 watch how the fire moves to the breach in the wing and then to the rear of the 656 00:14:07,110 --> 00:14:07,120 in the wing and then to the rear of the 657 00:14:07,120 --> 00:14:09,269 in the wing and then to the rear of the airplane as it follows the fuel spilled 658 00:14:09,269 --> 00:14:09,279 airplane as it follows the fuel spilled 659 00:14:09,279 --> 00:14:11,110 airplane as it follows the fuel spilled in the slide path of the crashed 660 00:14:11,110 --> 00:14:11,120 in the slide path of the crashed 661 00:14:11,120 --> 00:14:17,350 in the slide path of the crashed airplane 662 00:14:17,350 --> 00:14:17,360 663 00:14:17,360 --> 00:14:19,350 finally it is necessary to consider the 664 00:14:19,350 --> 00:14:19,360 finally it is necessary to consider the 665 00:14:19,360 --> 00:14:21,990 finally it is necessary to consider the time during which the mist is a hazard 666 00:14:21,990 --> 00:14:22,000 time during which the mist is a hazard 667 00:14:22,000 --> 00:14:24,470 time during which the mist is a hazard this is a rear view at one third normal 668 00:14:24,470 --> 00:14:24,480 this is a rear view at one third normal 669 00:14:24,480 --> 00:14:26,710 this is a rear view at one third normal speed which places the fuel mist between 670 00:14:26,710 --> 00:14:26,720 speed which places the fuel mist between 671 00:14:26,720 --> 00:14:28,629 speed which places the fuel mist between the airplane and the camera the 672 00:14:28,629 --> 00:14:28,639 the airplane and the camera the 673 00:14:28,639 --> 00:14:30,470 the airplane and the camera the developing fuel mist obscures the 674 00:14:30,470 --> 00:14:30,480 developing fuel mist obscures the 675 00:14:30,480 --> 00:14:32,870 developing fuel mist obscures the airplane from view but it reappears 676 00:14:32,870 --> 00:14:32,880 airplane from view but it reappears 677 00:14:32,880 --> 00:14:35,430 airplane from view but it reappears shortly as the large mist droplets rain 678 00:14:35,430 --> 00:14:35,440 shortly as the large mist droplets rain 679 00:14:35,440 --> 00:14:37,670 shortly as the large mist droplets rain to the ground and the small droplets are 680 00:14:37,670 --> 00:14:37,680 to the ground and the small droplets are 681 00:14:37,680 --> 00:14:39,829 to the ground and the small droplets are swept from the area by the wind as they 682 00:14:39,829 --> 00:14:39,839 swept from the area by the wind as they 683 00:14:39,839 --> 00:14:42,310 swept from the area by the wind as they evaporate these mists seldom remain 684 00:14:42,310 --> 00:14:42,320 evaporate these mists seldom remain 685 00:14:42,320 --> 00:14:44,069 evaporate these mists seldom remain around the crashed airplane for more 686 00:14:44,069 --> 00:14:44,079 around the crashed airplane for more 687 00:14:44,079 --> 00:14:45,910 around the crashed airplane for more than 15 seconds 688 00:14:45,910 --> 00:14:45,920 than 15 seconds 689 00:14:45,920 --> 00:14:47,990 than 15 seconds analysis of the photographic data shows 690 00:14:47,990 --> 00:14:48,000 analysis of the photographic data shows 691 00:14:48,000 --> 00:14:50,550 analysis of the photographic data shows that this fuel missed hazard time varies 692 00:14:50,550 --> 00:14:50,560 that this fuel missed hazard time varies 693 00:14:50,560 --> 00:14:53,030 that this fuel missed hazard time varies inversely with the wind speed around the 694 00:14:53,030 --> 00:14:53,040 inversely with the wind speed around the 695 00:14:53,040 --> 00:15:00,069 inversely with the wind speed around the crashed airplane 696 00:15:00,069 --> 00:15:00,079 697 00:15:00,079 --> 00:15:01,829 to sum up it has been shown that 698 00:15:01,829 --> 00:15:01,839 to sum up it has been shown that 699 00:15:01,839 --> 00:15:04,389 to sum up it has been shown that airborne fuel mist can move considerable 700 00:15:04,389 --> 00:15:04,399 airborne fuel mist can move considerable 701 00:15:04,399 --> 00:15:06,710 airborne fuel mist can move considerable distance forward and span wise from the 702 00:15:06,710 --> 00:15:06,720 distance forward and span wise from the 703 00:15:06,720 --> 00:15:08,949 distance forward and span wise from the fuel spillage point to reach remote 704 00:15:08,949 --> 00:15:08,959 fuel spillage point to reach remote 705 00:15:08,959 --> 00:15:11,030 fuel spillage point to reach remote ignition sources 706 00:15:11,030 --> 00:15:11,040 ignition sources 707 00:15:11,040 --> 00:15:13,110 ignition sources when the fuel is dispersed as missed it 708 00:15:13,110 --> 00:15:13,120 when the fuel is dispersed as missed it 709 00:15:13,120 --> 00:15:14,710 when the fuel is dispersed as missed it ignites readily even though its 710 00:15:14,710 --> 00:15:14,720 ignites readily even though its 711 00:15:14,720 --> 00:15:17,030 ignites readily even though its volatility is low 712 00:15:17,030 --> 00:15:17,040 volatility is low 713 00:15:17,040 --> 00:15:19,269 volatility is low contact between the mist and an ignition 714 00:15:19,269 --> 00:15:19,279 contact between the mist and an ignition 715 00:15:19,279 --> 00:15:21,509 contact between the mist and an ignition source far from the fuel spillage zones 716 00:15:21,509 --> 00:15:21,519 source far from the fuel spillage zones 717 00:15:21,519 --> 00:15:23,670 source far from the fuel spillage zones is most likely to occur as the airplane 718 00:15:23,670 --> 00:15:23,680 is most likely to occur as the airplane 719 00:15:23,680 --> 00:15:25,430 is most likely to occur as the airplane slows down 720 00:15:25,430 --> 00:15:25,440 slows down 721 00:15:25,440 --> 00:15:27,350 slows down because of the short duration time of 722 00:15:27,350 --> 00:15:27,360 because of the short duration time of 723 00:15:27,360 --> 00:15:29,430 because of the short duration time of the mist the ignition source must be 724 00:15:29,430 --> 00:15:29,440 the mist the ignition source must be 725 00:15:29,440 --> 00:15:31,350 the mist the ignition source must be present while the airplane is in motion 726 00:15:31,350 --> 00:15:31,360 present while the airplane is in motion 727 00:15:31,360 --> 00:15:34,310 present while the airplane is in motion or shortly after it stops if a fire is 728 00:15:34,310 --> 00:15:34,320 or shortly after it stops if a fire is 729 00:15:34,320 --> 00:15:36,069 or shortly after it stops if a fire is to occur 730 00:15:36,069 --> 00:15:36,079 to occur 731 00:15:36,079 --> 00:15:37,990 to occur now let us see how crash fires are 732 00:15:37,990 --> 00:15:38,000 now let us see how crash fires are 733 00:15:38,000 --> 00:15:39,910 now let us see how crash fires are started with fuel spillage in liquid 734 00:15:39,910 --> 00:15:39,920 started with fuel spillage in liquid 735 00:15:39,920 --> 00:15:42,389 started with fuel spillage in liquid form fuel in liquid form appears on the 736 00:15:42,389 --> 00:15:42,399 form fuel in liquid form appears on the 737 00:15:42,399 --> 00:15:44,389 form fuel in liquid form appears on the outside of the airplane pouring to the 738 00:15:44,389 --> 00:15:44,399 outside of the airplane pouring to the 739 00:15:44,399 --> 00:15:46,389 outside of the airplane pouring to the ground from the broken fuel tank and 740 00:15:46,389 --> 00:15:46,399 ground from the broken fuel tank and 741 00:15:46,399 --> 00:15:47,829 ground from the broken fuel tank and fuel lines 742 00:15:47,829 --> 00:15:47,839 fuel lines 743 00:15:47,839 --> 00:15:49,350 fuel lines the steam that is issuing from the 744 00:15:49,350 --> 00:15:49,360 the steam that is issuing from the 745 00:15:49,360 --> 00:15:51,749 the steam that is issuing from the nacelle will be discussed later liquid 746 00:15:51,749 --> 00:15:51,759 nacelle will be discussed later liquid 747 00:15:51,759 --> 00:15:53,749 nacelle will be discussed later liquid fuel also collects on the airplane 748 00:15:53,749 --> 00:15:53,759 fuel also collects on the airplane 749 00:15:53,759 --> 00:15:55,829 fuel also collects on the airplane surfaces by interception of the fuel 750 00:15:55,829 --> 00:15:55,839 surfaces by interception of the fuel 751 00:15:55,839 --> 00:15:58,230 surfaces by interception of the fuel mist droplets while the streams of 752 00:15:58,230 --> 00:15:58,240 mist droplets while the streams of 753 00:15:58,240 --> 00:16:00,230 mist droplets while the streams of liquid fuel pouring to the ground are 754 00:16:00,230 --> 00:16:00,240 liquid fuel pouring to the ground are 755 00:16:00,240 --> 00:16:02,310 liquid fuel pouring to the ground are formed as the airplane comes to a stop 756 00:16:02,310 --> 00:16:02,320 formed as the airplane comes to a stop 757 00:16:02,320 --> 00:16:04,550 formed as the airplane comes to a stop and mist formation subsides 758 00:16:04,550 --> 00:16:04,560 and mist formation subsides 759 00:16:04,560 --> 00:16:06,389 and mist formation subsides spreading of the liquid fuel within the 760 00:16:06,389 --> 00:16:06,399 spreading of the liquid fuel within the 761 00:16:06,399 --> 00:16:08,629 spreading of the liquid fuel within the airplane structure begins as soon as the 762 00:16:08,629 --> 00:16:08,639 airplane structure begins as soon as the 763 00:16:08,639 --> 00:16:10,790 airplane structure begins as soon as the tanks are damaged regardless of the 764 00:16:10,790 --> 00:16:10,800 tanks are damaged regardless of the 765 00:16:10,800 --> 00:16:13,350 tanks are damaged regardless of the state of motion of the airplane 766 00:16:13,350 --> 00:16:13,360 state of motion of the airplane 767 00:16:13,360 --> 00:16:15,670 state of motion of the airplane when liquid fuel is spilled inside the 768 00:16:15,670 --> 00:16:15,680 when liquid fuel is spilled inside the 769 00:16:15,680 --> 00:16:17,590 when liquid fuel is spilled inside the airplane structure such as the wing 770 00:16:17,590 --> 00:16:17,600 airplane structure such as the wing 771 00:16:17,600 --> 00:16:20,310 airplane structure such as the wing interior combustible concentrations of 772 00:16:20,310 --> 00:16:20,320 interior combustible concentrations of 773 00:16:20,320 --> 00:16:22,790 interior combustible concentrations of fuel vapor accumulate readily and spread 774 00:16:22,790 --> 00:16:22,800 fuel vapor accumulate readily and spread 775 00:16:22,800 --> 00:16:25,189 fuel vapor accumulate readily and spread within the structure as an example of 776 00:16:25,189 --> 00:16:25,199 within the structure as an example of 777 00:16:25,199 --> 00:16:27,189 within the structure as an example of the ignition of fuel spilled within the 778 00:16:27,189 --> 00:16:27,199 the ignition of fuel spilled within the 779 00:16:27,199 --> 00:16:29,990 the ignition of fuel spilled within the wing observe the wing fire set by 780 00:16:29,990 --> 00:16:30,000 wing observe the wing fire set by 781 00:16:30,000 --> 00:16:31,749 wing observe the wing fire set by damaged landing lights on the leading 782 00:16:31,749 --> 00:16:31,759 damaged landing lights on the leading 783 00:16:31,759 --> 00:16:33,110 damaged landing lights on the leading edge of the wing 784 00:16:33,110 --> 00:16:33,120 edge of the wing 785 00:16:33,120 --> 00:16:35,430 edge of the wing the poles that rip open the fuel tanks 786 00:16:35,430 --> 00:16:35,440 the poles that rip open the fuel tanks 787 00:16:35,440 --> 00:16:37,670 the poles that rip open the fuel tanks also smash the landing lights and drive 788 00:16:37,670 --> 00:16:37,680 also smash the landing lights and drive 789 00:16:37,680 --> 00:16:39,509 also smash the landing lights and drive them into the wing where the 790 00:16:39,509 --> 00:16:39,519 them into the wing where the 791 00:16:39,519 --> 00:16:41,990 them into the wing where the incandescent filaments set fire to the 792 00:16:41,990 --> 00:16:42,000 incandescent filaments set fire to the 793 00:16:42,000 --> 00:16:44,310 incandescent filaments set fire to the fuel almost at once 794 00:16:44,310 --> 00:16:44,320 fuel almost at once 795 00:16:44,320 --> 00:16:45,990 fuel almost at once the next motion picture sequence 796 00:16:45,990 --> 00:16:46,000 the next motion picture sequence 797 00:16:46,000 --> 00:16:48,550 the next motion picture sequence projected at one-fifth normal speed 798 00:16:48,550 --> 00:16:48,560 projected at one-fifth normal speed 799 00:16:48,560 --> 00:16:50,629 projected at one-fifth normal speed shows ignition by the damaged landing 800 00:16:50,629 --> 00:16:50,639 shows ignition by the damaged landing 801 00:16:50,639 --> 00:16:53,030 shows ignition by the damaged landing lights the pole at the barrier drives 802 00:16:53,030 --> 00:16:53,040 lights the pole at the barrier drives 803 00:16:53,040 --> 00:16:55,430 lights the pole at the barrier drives the landing light into the fuel tanks 804 00:16:55,430 --> 00:16:55,440 the landing light into the fuel tanks 805 00:16:55,440 --> 00:16:57,430 the landing light into the fuel tanks the resulting fire spreads rapidly 806 00:16:57,430 --> 00:16:57,440 the resulting fire spreads rapidly 807 00:16:57,440 --> 00:16:59,269 the resulting fire spreads rapidly through the fuel mist to produce this 808 00:16:59,269 --> 00:16:59,279 through the fuel mist to produce this 809 00:16:59,279 --> 00:17:17,590 through the fuel mist to produce this wall of flame 810 00:17:17,590 --> 00:17:17,600 811 00:17:17,600 --> 00:17:20,470 the mass of fuel mist rises as it burns 812 00:17:20,470 --> 00:17:20,480 the mass of fuel mist rises as it burns 813 00:17:20,480 --> 00:17:22,870 the mass of fuel mist rises as it burns out the fuel evaporating from liquid 814 00:17:22,870 --> 00:17:22,880 out the fuel evaporating from liquid 815 00:17:22,880 --> 00:17:24,789 out the fuel evaporating from liquid spillage on the ground and the wetted 816 00:17:24,789 --> 00:17:24,799 spillage on the ground and the wetted 817 00:17:24,799 --> 00:17:26,870 spillage on the ground and the wetted surfaces of the airplane continues the 818 00:17:26,870 --> 00:17:26,880 surfaces of the airplane continues the 819 00:17:26,880 --> 00:17:40,470 surfaces of the airplane continues the fire on a reduced scale 820 00:17:40,470 --> 00:17:40,480 821 00:17:40,480 --> 00:17:42,470 the fuel that spills in the wing can 822 00:17:42,470 --> 00:17:42,480 the fuel that spills in the wing can 823 00:17:42,480 --> 00:17:44,390 the fuel that spills in the wing can also move through channels within the 824 00:17:44,390 --> 00:17:44,400 also move through channels within the 825 00:17:44,400 --> 00:17:46,789 also move through channels within the wing to ignition sources contained in 826 00:17:46,789 --> 00:17:46,799 wing to ignition sources contained in 827 00:17:46,799 --> 00:17:48,870 wing to ignition sources contained in other parts of the airplane 828 00:17:48,870 --> 00:17:48,880 other parts of the airplane 829 00:17:48,880 --> 00:17:50,870 other parts of the airplane one path this fuel may take is through 830 00:17:50,870 --> 00:17:50,880 one path this fuel may take is through 831 00:17:50,880 --> 00:17:53,510 one path this fuel may take is through the duct in the wing leading edge this 832 00:17:53,510 --> 00:17:53,520 the duct in the wing leading edge this 833 00:17:53,520 --> 00:17:55,750 the duct in the wing leading edge this duct carries hot air to warm the wing 834 00:17:55,750 --> 00:17:55,760 duct carries hot air to warm the wing 835 00:17:55,760 --> 00:17:57,830 duct carries hot air to warm the wing and prevent the accumulation of ice in 836 00:17:57,830 --> 00:17:57,840 and prevent the accumulation of ice in 837 00:17:57,840 --> 00:17:58,789 and prevent the accumulation of ice in flight 838 00:17:58,789 --> 00:17:58,799 flight 839 00:17:58,799 --> 00:18:00,789 flight the duck leads to a heat exchanger at 840 00:18:00,789 --> 00:18:00,799 the duck leads to a heat exchanger at 841 00:18:00,799 --> 00:18:02,710 the duck leads to a heat exchanger at the engine exhaust tailpipe which 842 00:18:02,710 --> 00:18:02,720 the engine exhaust tailpipe which 843 00:18:02,720 --> 00:18:04,630 the engine exhaust tailpipe which provides the necessary heat 844 00:18:04,630 --> 00:18:04,640 provides the necessary heat 845 00:18:04,640 --> 00:18:06,630 provides the necessary heat when this duct is ripped open as the 846 00:18:06,630 --> 00:18:06,640 when this duct is ripped open as the 847 00:18:06,640 --> 00:18:09,110 when this duct is ripped open as the poles tear through the wing some of the 848 00:18:09,110 --> 00:18:09,120 poles tear through the wing some of the 849 00:18:09,120 --> 00:18:11,270 poles tear through the wing some of the fuel issuing from the torn tanks is 850 00:18:11,270 --> 00:18:11,280 fuel issuing from the torn tanks is 851 00:18:11,280 --> 00:18:13,430 fuel issuing from the torn tanks is diverted into the duct 852 00:18:13,430 --> 00:18:13,440 diverted into the duct 853 00:18:13,440 --> 00:18:16,150 diverted into the duct this fuel flows by gravity to the hot 854 00:18:16,150 --> 00:18:16,160 this fuel flows by gravity to the hot 855 00:18:16,160 --> 00:18:17,590 this fuel flows by gravity to the hot heat exchanger 856 00:18:17,590 --> 00:18:17,600 heat exchanger 857 00:18:17,600 --> 00:18:20,070 heat exchanger upon ignition the flame flashes back 858 00:18:20,070 --> 00:18:20,080 upon ignition the flame flashes back 859 00:18:20,080 --> 00:18:22,150 upon ignition the flame flashes back through the hot air duct to the fuel in 860 00:18:22,150 --> 00:18:22,160 through the hot air duct to the fuel in 861 00:18:22,160 --> 00:18:26,070 through the hot air duct to the fuel in the wing 862 00:18:26,070 --> 00:18:26,080 863 00:18:26,080 --> 00:18:27,990 here is a crash in which these events 864 00:18:27,990 --> 00:18:28,000 here is a crash in which these events 865 00:18:28,000 --> 00:18:30,070 here is a crash in which these events occurred because the wing slopes 866 00:18:30,070 --> 00:18:30,080 occurred because the wing slopes 867 00:18:30,080 --> 00:18:32,070 occurred because the wing slopes gradually toward the nacelle a fuel 868 00:18:32,070 --> 00:18:32,080 gradually toward the nacelle a fuel 869 00:18:32,080 --> 00:18:33,590 gradually toward the nacelle a fuel flowing through the hot air duct 870 00:18:33,590 --> 00:18:33,600 flowing through the hot air duct 871 00:18:33,600 --> 00:18:36,390 flowing through the hot air duct requires 14 seconds to reach the cell 872 00:18:36,390 --> 00:18:36,400 requires 14 seconds to reach the cell 873 00:18:36,400 --> 00:18:38,230 requires 14 seconds to reach the cell since the action on film is reduced to 874 00:18:38,230 --> 00:18:38,240 since the action on film is reduced to 875 00:18:38,240 --> 00:18:40,950 since the action on film is reduced to one-fifth normal speed about one minute 876 00:18:40,950 --> 00:18:40,960 one-fifth normal speed about one minute 877 00:18:40,960 --> 00:18:43,510 one-fifth normal speed about one minute will pass before this ignition appears 878 00:18:43,510 --> 00:18:43,520 will pass before this ignition appears 879 00:18:43,520 --> 00:18:45,270 will pass before this ignition appears the steam which is issuing from the 880 00:18:45,270 --> 00:18:45,280 the steam which is issuing from the 881 00:18:45,280 --> 00:18:53,190 the steam which is issuing from the nacelle will be discussed shortly 882 00:18:53,190 --> 00:18:53,200 883 00:18:53,200 --> 00:18:55,430 the fire will show first at the engine 884 00:18:55,430 --> 00:18:55,440 the fire will show first at the engine 885 00:18:55,440 --> 00:18:57,909 the fire will show first at the engine tailpipe heat exchanger on your right 886 00:18:57,909 --> 00:18:57,919 tailpipe heat exchanger on your right 887 00:18:57,919 --> 00:18:59,990 tailpipe heat exchanger on your right note the spread of the fire back to the 888 00:18:59,990 --> 00:19:00,000 note the spread of the fire back to the 889 00:19:00,000 --> 00:19:07,270 note the spread of the fire back to the wing and the wing explosion that results 890 00:19:07,270 --> 00:19:07,280 891 00:19:07,280 --> 00:19:09,350 in addition to the flow of liquid fuel 892 00:19:09,350 --> 00:19:09,360 in addition to the flow of liquid fuel 893 00:19:09,360 --> 00:19:11,029 in addition to the flow of liquid fuel through the internal channels of the 894 00:19:11,029 --> 00:19:11,039 through the internal channels of the 895 00:19:11,039 --> 00:19:13,430 through the internal channels of the airplane fuel and rivulets and sheets 896 00:19:13,430 --> 00:19:13,440 airplane fuel and rivulets and sheets 897 00:19:13,440 --> 00:19:15,990 airplane fuel and rivulets and sheets flows by gravity along the underside of 898 00:19:15,990 --> 00:19:16,000 flows by gravity along the underside of 899 00:19:16,000 --> 00:19:18,630 flows by gravity along the underside of inclined airplane services this will be 900 00:19:18,630 --> 00:19:18,640 inclined airplane services this will be 901 00:19:18,640 --> 00:19:21,029 inclined airplane services this will be called wetting conduction fuel which 902 00:19:21,029 --> 00:19:21,039 called wetting conduction fuel which 903 00:19:21,039 --> 00:19:23,270 called wetting conduction fuel which spills inside the wing can seep through 904 00:19:23,270 --> 00:19:23,280 spills inside the wing can seep through 905 00:19:23,280 --> 00:19:25,270 spills inside the wing can seep through seams in the wing's skin and cling to 906 00:19:25,270 --> 00:19:25,280 seams in the wing's skin and cling to 907 00:19:25,280 --> 00:19:27,750 seams in the wing's skin and cling to the under surface of the wing this fuel 908 00:19:27,750 --> 00:19:27,760 the under surface of the wing this fuel 909 00:19:27,760 --> 00:19:29,430 the under surface of the wing this fuel may then flow to other parts of the 910 00:19:29,430 --> 00:19:29,440 may then flow to other parts of the 911 00:19:29,440 --> 00:19:31,830 may then flow to other parts of the airplane where ignition sources exist 912 00:19:31,830 --> 00:19:31,840 airplane where ignition sources exist 913 00:19:31,840 --> 00:19:34,070 airplane where ignition sources exist the resulting fire travels back along 914 00:19:34,070 --> 00:19:34,080 the resulting fire travels back along 915 00:19:34,080 --> 00:19:36,789 the resulting fire travels back along the fuel path to the fuel source the 916 00:19:36,789 --> 00:19:36,799 the fuel path to the fuel source the 917 00:19:36,799 --> 00:19:38,630 the fuel path to the fuel source the wetting conduction of the fuel along the 918 00:19:38,630 --> 00:19:38,640 wetting conduction of the fuel along the 919 00:19:38,640 --> 00:19:40,470 wetting conduction of the fuel along the under surface of the inclined wing is 920 00:19:40,470 --> 00:19:40,480 under surface of the inclined wing is 921 00:19:40,480 --> 00:19:42,710 under surface of the inclined wing is illustrated by a simple experiment in 922 00:19:42,710 --> 00:19:42,720 illustrated by a simple experiment in 923 00:19:42,720 --> 00:19:44,870 illustrated by a simple experiment in which fuel issuing from an opening in a 924 00:19:44,870 --> 00:19:44,880 which fuel issuing from an opening in a 925 00:19:44,880 --> 00:19:47,430 which fuel issuing from an opening in a tube at the raised end wets and moves 926 00:19:47,430 --> 00:19:47,440 tube at the raised end wets and moves 927 00:19:47,440 --> 00:19:50,310 tube at the raised end wets and moves along the under surface to the low end 928 00:19:50,310 --> 00:19:50,320 along the under surface to the low end 929 00:19:50,320 --> 00:19:52,310 along the under surface to the low end the normal wing arrangement of airplanes 930 00:19:52,310 --> 00:19:52,320 the normal wing arrangement of airplanes 931 00:19:52,320 --> 00:19:54,150 the normal wing arrangement of airplanes may place the wingtips higher than the 932 00:19:54,150 --> 00:19:54,160 may place the wingtips higher than the 933 00:19:54,160 --> 00:19:56,870 may place the wingtips higher than the wing at the engine the cells for these 934 00:19:56,870 --> 00:19:56,880 wing at the engine the cells for these 935 00:19:56,880 --> 00:19:59,190 wing at the engine the cells for these airplanes the wetting conduction flow is 936 00:19:59,190 --> 00:19:59,200 airplanes the wetting conduction flow is 937 00:19:59,200 --> 00:20:00,950 airplanes the wetting conduction flow is toward the nacelle where ignition 938 00:20:00,950 --> 00:20:00,960 toward the nacelle where ignition 939 00:20:00,960 --> 00:20:05,430 toward the nacelle where ignition sources exist 940 00:20:05,430 --> 00:20:05,440 941 00:20:05,440 --> 00:20:07,430 sometimes in a crash the wing 942 00:20:07,430 --> 00:20:07,440 sometimes in a crash the wing 943 00:20:07,440 --> 00:20:09,190 sometimes in a crash the wing inclination is even higher which 944 00:20:09,190 --> 00:20:09,200 inclination is even higher which 945 00:20:09,200 --> 00:20:11,270 inclination is even higher which increases the fuel movement by wetting 946 00:20:11,270 --> 00:20:11,280 increases the fuel movement by wetting 947 00:20:11,280 --> 00:20:13,750 increases the fuel movement by wetting conduction distribution of fuel by 948 00:20:13,750 --> 00:20:13,760 conduction distribution of fuel by 949 00:20:13,760 --> 00:20:15,909 conduction distribution of fuel by wetting conduction is shown on the 950 00:20:15,909 --> 00:20:15,919 wetting conduction is shown on the 951 00:20:15,919 --> 00:20:18,310 wetting conduction is shown on the underside of this wing of a crashed 952 00:20:18,310 --> 00:20:18,320 underside of this wing of a crashed 953 00:20:18,320 --> 00:20:21,270 underside of this wing of a crashed airplane which did not burn the fuel dye 954 00:20:21,270 --> 00:20:21,280 airplane which did not burn the fuel dye 955 00:20:21,280 --> 00:20:23,430 airplane which did not burn the fuel dye indicates the path of the fuel the 956 00:20:23,430 --> 00:20:23,440 indicates the path of the fuel the 957 00:20:23,440 --> 00:20:25,909 indicates the path of the fuel the continuous fuel wetted path extends from 958 00:20:25,909 --> 00:20:25,919 continuous fuel wetted path extends from 959 00:20:25,919 --> 00:20:27,990 continuous fuel wetted path extends from the break in the wing to the nacelle and 960 00:20:27,990 --> 00:20:28,000 the break in the wing to the nacelle and 961 00:20:28,000 --> 00:20:32,710 the break in the wing to the nacelle and the engine exhaust pipe 962 00:20:32,710 --> 00:20:32,720 963 00:20:32,720 --> 00:20:34,870 here is how the wetting conduction flow 964 00:20:34,870 --> 00:20:34,880 here is how the wetting conduction flow 965 00:20:34,880 --> 00:20:37,590 here is how the wetting conduction flow looks immediately after a crash the fuel 966 00:20:37,590 --> 00:20:37,600 looks immediately after a crash the fuel 967 00:20:37,600 --> 00:20:39,590 looks immediately after a crash the fuel on the underside of the wing clings and 968 00:20:39,590 --> 00:20:39,600 on the underside of the wing clings and 969 00:20:39,600 --> 00:20:42,310 on the underside of the wing clings and flows by gravity along the wing span 970 00:20:42,310 --> 00:20:42,320 flows by gravity along the wing span 971 00:20:42,320 --> 00:20:44,230 flows by gravity along the wing span some of the fuel dripping off along the 972 00:20:44,230 --> 00:20:44,240 some of the fuel dripping off along the 973 00:20:44,240 --> 00:20:45,830 some of the fuel dripping off along the way 974 00:20:45,830 --> 00:20:45,840 way 975 00:20:45,840 --> 00:20:48,230 way fuel sometimes runs into the wheel well 976 00:20:48,230 --> 00:20:48,240 fuel sometimes runs into the wheel well 977 00:20:48,240 --> 00:20:50,230 fuel sometimes runs into the wheel well from broken tanks through channels in 978 00:20:50,230 --> 00:20:50,240 from broken tanks through channels in 979 00:20:50,240 --> 00:20:53,110 from broken tanks through channels in the wing structure 980 00:20:53,110 --> 00:20:53,120 the wing structure 981 00:20:53,120 --> 00:20:54,870 the wing structure here you see how it dripped and ran 982 00:20:54,870 --> 00:20:54,880 here you see how it dripped and ran 983 00:20:54,880 --> 00:20:57,029 here you see how it dripped and ran along various parts of the landing gear 984 00:20:57,029 --> 00:20:57,039 along various parts of the landing gear 985 00:20:57,039 --> 00:20:59,110 along various parts of the landing gear actuating system and along the strut 986 00:20:59,110 --> 00:20:59,120 actuating system and along the strut 987 00:20:59,120 --> 00:21:08,230 actuating system and along the strut toward the wheel 988 00:21:08,230 --> 00:21:08,240 989 00:21:08,240 --> 00:21:10,549 any marked change in the surface along 990 00:21:10,549 --> 00:21:10,559 any marked change in the surface along 991 00:21:10,559 --> 00:21:12,310 any marked change in the surface along which wetting conduction of fuel is 992 00:21:12,310 --> 00:21:12,320 which wetting conduction of fuel is 993 00:21:12,320 --> 00:21:14,390 which wetting conduction of fuel is taking place may interrupt this fuel 994 00:21:14,390 --> 00:21:14,400 taking place may interrupt this fuel 995 00:21:14,400 --> 00:21:16,710 taking place may interrupt this fuel flow here we see how a sharp edged 996 00:21:16,710 --> 00:21:16,720 flow here we see how a sharp edged 997 00:21:16,720 --> 00:21:18,710 flow here we see how a sharp edged projection intercepts the wetting 998 00:21:18,710 --> 00:21:18,720 projection intercepts the wetting 999 00:21:18,720 --> 00:21:20,789 projection intercepts the wetting conduction fuel flow and prevents 1000 00:21:20,789 --> 00:21:20,799 conduction fuel flow and prevents 1001 00:21:20,799 --> 00:21:26,070 conduction fuel flow and prevents further flow along the rod 1002 00:21:26,070 --> 00:21:26,080 1003 00:21:26,080 --> 00:21:28,149 a slot in the rod provides the same 1004 00:21:28,149 --> 00:21:28,159 a slot in the rod provides the same 1005 00:21:28,159 --> 00:21:30,070 a slot in the rod provides the same interception of the wetting conduction 1006 00:21:30,070 --> 00:21:30,080 interception of the wetting conduction 1007 00:21:30,080 --> 00:21:31,510 interception of the wetting conduction flow 1008 00:21:31,510 --> 00:21:31,520 flow 1009 00:21:31,520 --> 00:21:33,430 flow in cases where wetting conduction or 1010 00:21:33,430 --> 00:21:33,440 in cases where wetting conduction or 1011 00:21:33,440 --> 00:21:35,510 in cases where wetting conduction or fuel flow through structural channels 1012 00:21:35,510 --> 00:21:35,520 fuel flow through structural channels 1013 00:21:35,520 --> 00:21:37,909 fuel flow through structural channels results in prolonged contact between an 1014 00:21:37,909 --> 00:21:37,919 results in prolonged contact between an 1015 00:21:37,919 --> 00:21:40,549 results in prolonged contact between an igniter and the fuel in liquid form the 1016 00:21:40,549 --> 00:21:40,559 igniter and the fuel in liquid form the 1017 00:21:40,559 --> 00:21:43,029 igniter and the fuel in liquid form the use of fuels of low volatility would not 1018 00:21:43,029 --> 00:21:43,039 use of fuels of low volatility would not 1019 00:21:43,039 --> 00:21:47,669 use of fuels of low volatility would not materially reduce the likelihood of fire 1020 00:21:47,669 --> 00:21:47,679 1021 00:21:47,679 --> 00:21:49,990 where vaporization of the fuel across an 1022 00:21:49,990 --> 00:21:50,000 where vaporization of the fuel across an 1023 00:21:50,000 --> 00:21:51,830 where vaporization of the fuel across an air gap is required for the fuel to 1024 00:21:51,830 --> 00:21:51,840 air gap is required for the fuel to 1025 00:21:51,840 --> 00:21:54,630 air gap is required for the fuel to reach an igniter low volatility fuel 1026 00:21:54,630 --> 00:21:54,640 reach an igniter low volatility fuel 1027 00:21:54,640 --> 00:21:57,270 reach an igniter low volatility fuel provides a safety advantage consider 1028 00:21:57,270 --> 00:21:57,280 provides a safety advantage consider 1029 00:21:57,280 --> 00:21:59,510 provides a safety advantage consider next fuel spilling in the open air that 1030 00:21:59,510 --> 00:21:59,520 next fuel spilling in the open air that 1031 00:21:59,520 --> 00:22:01,750 next fuel spilling in the open air that wets the ground along the slide path of 1032 00:22:01,750 --> 00:22:01,760 wets the ground along the slide path of 1033 00:22:01,760 --> 00:22:03,510 wets the ground along the slide path of the airplane and around the crashed 1034 00:22:03,510 --> 00:22:03,520 the airplane and around the crashed 1035 00:22:03,520 --> 00:22:05,990 the airplane and around the crashed airplane at rest the pools of liquid 1036 00:22:05,990 --> 00:22:06,000 airplane at rest the pools of liquid 1037 00:22:06,000 --> 00:22:08,630 airplane at rest the pools of liquid fuel close to the nacelles are not large 1038 00:22:08,630 --> 00:22:08,640 fuel close to the nacelles are not large 1039 00:22:08,640 --> 00:22:10,710 fuel close to the nacelles are not large since most of the spilled fuel flows 1040 00:22:10,710 --> 00:22:10,720 since most of the spilled fuel flows 1041 00:22:10,720 --> 00:22:13,270 since most of the spilled fuel flows away from the spillage point ignitable 1042 00:22:13,270 --> 00:22:13,280 away from the spillage point ignitable 1043 00:22:13,280 --> 00:22:15,190 away from the spillage point ignitable fuel vapor from ground spillage is 1044 00:22:15,190 --> 00:22:15,200 fuel vapor from ground spillage is 1045 00:22:15,200 --> 00:22:17,029 fuel vapor from ground spillage is carried in a thin layer close to the 1046 00:22:17,029 --> 00:22:17,039 carried in a thin layer close to the 1047 00:22:17,039 --> 00:22:19,350 carried in a thin layer close to the ground the ignition hazard distance 1048 00:22:19,350 --> 00:22:19,360 ground the ignition hazard distance 1049 00:22:19,360 --> 00:22:21,270 ground the ignition hazard distance which extends only a few feet from the 1050 00:22:21,270 --> 00:22:21,280 which extends only a few feet from the 1051 00:22:21,280 --> 00:22:24,070 which extends only a few feet from the spillage decreases with increasing wind 1052 00:22:24,070 --> 00:22:24,080 spillage decreases with increasing wind 1053 00:22:24,080 --> 00:22:26,950 spillage decreases with increasing wind velocity this short hazard distance is 1054 00:22:26,950 --> 00:22:26,960 velocity this short hazard distance is 1055 00:22:26,960 --> 00:22:28,870 velocity this short hazard distance is illustrated by the ignition of gasoline 1056 00:22:28,870 --> 00:22:28,880 illustrated by the ignition of gasoline 1057 00:22:28,880 --> 00:22:31,590 illustrated by the ignition of gasoline vapors from pans by a lighted taper 1058 00:22:31,590 --> 00:22:31,600 vapors from pans by a lighted taper 1059 00:22:31,600 --> 00:22:33,990 vapors from pans by a lighted taper approaching from the downwind end 1060 00:22:33,990 --> 00:22:34,000 approaching from the downwind end 1061 00:22:34,000 --> 00:22:36,070 approaching from the downwind end when ignition occurs the lighted taper 1062 00:22:36,070 --> 00:22:36,080 when ignition occurs the lighted taper 1063 00:22:36,080 --> 00:22:37,990 when ignition occurs the lighted taper lies within two inches of the surface of 1064 00:22:37,990 --> 00:22:38,000 lies within two inches of the surface of 1065 00:22:38,000 --> 00:22:40,470 lies within two inches of the surface of the gasoline contained in the pans the 1066 00:22:40,470 --> 00:22:40,480 the gasoline contained in the pans the 1067 00:22:40,480 --> 00:22:43,029 the gasoline contained in the pans the wind speed is 10 miles an hour movement 1068 00:22:43,029 --> 00:22:43,039 wind speed is 10 miles an hour movement 1069 00:22:43,039 --> 00:22:45,190 wind speed is 10 miles an hour movement of combustible concentrations of fuel 1070 00:22:45,190 --> 00:22:45,200 of combustible concentrations of fuel 1071 00:22:45,200 --> 00:22:47,669 of combustible concentrations of fuel vapors from fuels filled in the open air 1072 00:22:47,669 --> 00:22:47,679 vapors from fuels filled in the open air 1073 00:22:47,679 --> 00:22:50,230 vapors from fuels filled in the open air to ignition sources above the ground is 1074 00:22:50,230 --> 00:22:50,240 to ignition sources above the ground is 1075 00:22:50,240 --> 00:22:56,070 to ignition sources above the ground is considered unlikely 1076 00:22:56,070 --> 00:22:56,080 1077 00:22:56,080 --> 00:22:58,070 however when the fuel is spilled into 1078 00:22:58,070 --> 00:22:58,080 however when the fuel is spilled into 1079 00:22:58,080 --> 00:22:59,990 however when the fuel is spilled into wind protected areas provided by the 1080 00:22:59,990 --> 00:23:00,000 wind protected areas provided by the 1081 00:23:00,000 --> 00:23:02,710 wind protected areas provided by the crashed airplane heavy ground vegetation 1082 00:23:02,710 --> 00:23:02,720 crashed airplane heavy ground vegetation 1083 00:23:02,720 --> 00:23:05,190 crashed airplane heavy ground vegetation or ground channels the combustible 1084 00:23:05,190 --> 00:23:05,200 or ground channels the combustible 1085 00:23:05,200 --> 00:23:07,590 or ground channels the combustible concentration of fuel vapors may travel 1086 00:23:07,590 --> 00:23:07,600 concentration of fuel vapors may travel 1087 00:23:07,600 --> 00:23:09,909 concentration of fuel vapors may travel a considerable distance the ignition 1088 00:23:09,909 --> 00:23:09,919 a considerable distance the ignition 1089 00:23:09,919 --> 00:23:11,909 a considerable distance the ignition source must appear close to the ground 1090 00:23:11,909 --> 00:23:11,919 source must appear close to the ground 1091 00:23:11,919 --> 00:23:14,549 source must appear close to the ground in order to contact these fuel vapors 1092 00:23:14,549 --> 00:23:14,559 in order to contact these fuel vapors 1093 00:23:14,559 --> 00:23:16,710 in order to contact these fuel vapors such ignition sources may be droplets of 1094 00:23:16,710 --> 00:23:16,720 such ignition sources may be droplets of 1095 00:23:16,720 --> 00:23:19,830 such ignition sources may be droplets of burning oil hydraulic fluid or pieces of 1096 00:23:19,830 --> 00:23:19,840 burning oil hydraulic fluid or pieces of 1097 00:23:19,840 --> 00:23:22,149 burning oil hydraulic fluid or pieces of hot metal broken from the engine exhaust 1098 00:23:22,149 --> 00:23:22,159 hot metal broken from the engine exhaust 1099 00:23:22,159 --> 00:23:23,750 hot metal broken from the engine exhaust disposal system 1100 00:23:23,750 --> 00:23:23,760 disposal system 1101 00:23:23,760 --> 00:23:25,590 disposal system friction sparks generated by the 1102 00:23:25,590 --> 00:23:25,600 friction sparks generated by the 1103 00:23:25,600 --> 00:23:27,909 friction sparks generated by the scraping of airplane metals on concrete 1104 00:23:27,909 --> 00:23:27,919 scraping of airplane metals on concrete 1105 00:23:27,919 --> 00:23:31,029 scraping of airplane metals on concrete runways or stony ground provide one type 1106 00:23:31,029 --> 00:23:31,039 runways or stony ground provide one type 1107 00:23:31,039 --> 00:23:32,870 runways or stony ground provide one type of ignition source which appears close 1108 00:23:32,870 --> 00:23:32,880 of ignition source which appears close 1109 00:23:32,880 --> 00:23:35,110 of ignition source which appears close to the ground these sparks may ignite 1110 00:23:35,110 --> 00:23:35,120 to the ground these sparks may ignite 1111 00:23:35,120 --> 00:23:37,510 to the ground these sparks may ignite fuel on the ground in order to study 1112 00:23:37,510 --> 00:23:37,520 fuel on the ground in order to study 1113 00:23:37,520 --> 00:23:39,510 fuel on the ground in order to study this type of ignition a concrete strip 1114 00:23:39,510 --> 00:23:39,520 this type of ignition a concrete strip 1115 00:23:39,520 --> 00:23:41,350 this type of ignition a concrete strip was built along the slide path of the 1116 00:23:41,350 --> 00:23:41,360 was built along the slide path of the 1117 00:23:41,360 --> 00:23:43,750 was built along the slide path of the crashed airplane 1118 00:23:43,750 --> 00:23:43,760 crashed airplane 1119 00:23:43,760 --> 00:23:45,909 crashed airplane selected samples of airplane metals were 1120 00:23:45,909 --> 00:23:45,919 selected samples of airplane metals were 1121 00:23:45,919 --> 00:23:48,070 selected samples of airplane metals were fastened to protruding ends of pneumatic 1122 00:23:48,070 --> 00:23:48,080 fastened to protruding ends of pneumatic 1123 00:23:48,080 --> 00:23:50,310 fastened to protruding ends of pneumatic wheel struts salvaged from airplanes 1124 00:23:50,310 --> 00:23:50,320 wheel struts salvaged from airplanes 1125 00:23:50,320 --> 00:23:53,029 wheel struts salvaged from airplanes crashed in this study upon crash these 1126 00:23:53,029 --> 00:23:53,039 crashed in this study upon crash these 1127 00:23:53,039 --> 00:23:55,510 crashed in this study upon crash these metal samples bear on the concrete strip 1128 00:23:55,510 --> 00:23:55,520 metal samples bear on the concrete strip 1129 00:23:55,520 --> 00:23:57,510 metal samples bear on the concrete strip with a contact force great enough to 1130 00:23:57,510 --> 00:23:57,520 with a contact force great enough to 1131 00:23:57,520 --> 00:23:59,830 with a contact force great enough to produce sparks of sufficient size and 1132 00:23:59,830 --> 00:23:59,840 produce sparks of sufficient size and 1133 00:23:59,840 --> 00:24:02,070 produce sparks of sufficient size and temperature to ignite aviation grade 1134 00:24:02,070 --> 00:24:02,080 temperature to ignite aviation grade 1135 00:24:02,080 --> 00:24:04,789 temperature to ignite aviation grade gasoline sparks from this portion of a 1136 00:24:04,789 --> 00:24:04,799 gasoline sparks from this portion of a 1137 00:24:04,799 --> 00:24:07,190 gasoline sparks from this portion of a steel propeller blade and this steel 1138 00:24:07,190 --> 00:24:07,200 steel propeller blade and this steel 1139 00:24:07,200 --> 00:24:10,230 steel propeller blade and this steel wheel strut produced fires 1140 00:24:10,230 --> 00:24:10,240 wheel strut produced fires 1141 00:24:10,240 --> 00:24:12,149 wheel strut produced fires a braided particles of this portion of 1142 00:24:12,149 --> 00:24:12,159 a braided particles of this portion of 1143 00:24:12,159 --> 00:24:14,070 a braided particles of this portion of an aluminum propeller blade did not 1144 00:24:14,070 --> 00:24:14,080 an aluminum propeller blade did not 1145 00:24:14,080 --> 00:24:16,710 an aluminum propeller blade did not produce ignition in order to ensure an 1146 00:24:16,710 --> 00:24:16,720 produce ignition in order to ensure an 1147 00:24:16,720 --> 00:24:18,710 produce ignition in order to ensure an ignitable mixture close to the ground 1148 00:24:18,710 --> 00:24:18,720 ignitable mixture close to the ground 1149 00:24:18,720 --> 00:24:21,350 ignitable mixture close to the ground near the sparks secondary fuel spillage 1150 00:24:21,350 --> 00:24:21,360 near the sparks secondary fuel spillage 1151 00:24:21,360 --> 00:24:23,350 near the sparks secondary fuel spillage was provided by the spray bar at the 1152 00:24:23,350 --> 00:24:23,360 was provided by the spray bar at the 1153 00:24:23,360 --> 00:24:25,830 was provided by the spray bar at the nose of the fuselage and these spray 1154 00:24:25,830 --> 00:24:25,840 nose of the fuselage and these spray 1155 00:24:25,840 --> 00:24:30,549 nose of the fuselage and these spray nozzles along the side of the fuselage 1156 00:24:30,549 --> 00:24:30,559 1157 00:24:30,559 --> 00:24:32,390 ignition will appear at this point on 1158 00:24:32,390 --> 00:24:32,400 ignition will appear at this point on 1159 00:24:32,400 --> 00:24:34,470 ignition will appear at this point on the fuselage where a portion of a steel 1160 00:24:34,470 --> 00:24:34,480 the fuselage where a portion of a steel 1161 00:24:34,480 --> 00:24:37,669 the fuselage where a portion of a steel propeller blade is located 1162 00:24:37,669 --> 00:24:37,679 propeller blade is located 1163 00:24:37,679 --> 00:24:39,590 propeller blade is located here we see the airplane sliding along 1164 00:24:39,590 --> 00:24:39,600 here we see the airplane sliding along 1165 00:24:39,600 --> 00:24:41,830 here we see the airplane sliding along the concrete strip after undergoing the 1166 00:24:41,830 --> 00:24:41,840 the concrete strip after undergoing the 1167 00:24:41,840 --> 00:24:44,149 the concrete strip after undergoing the usual crash damage at the barrier the 1168 00:24:44,149 --> 00:24:44,159 usual crash damage at the barrier the 1169 00:24:44,159 --> 00:24:46,230 usual crash damage at the barrier the action is slowed to one-fifth normal 1170 00:24:46,230 --> 00:24:46,240 action is slowed to one-fifth normal 1171 00:24:46,240 --> 00:24:47,110 action is slowed to one-fifth normal speed 1172 00:24:47,110 --> 00:24:47,120 speed 1173 00:24:47,120 --> 00:24:48,630 speed the ignition will appear at the bottom 1174 00:24:48,630 --> 00:24:48,640 the ignition will appear at the bottom 1175 00:24:48,640 --> 00:24:50,470 the ignition will appear at the bottom of the fuselage this is the first 1176 00:24:50,470 --> 00:24:50,480 of the fuselage this is the first 1177 00:24:50,480 --> 00:24:52,789 of the fuselage this is the first ignition and here is the second friction 1178 00:24:52,789 --> 00:24:52,799 ignition and here is the second friction 1179 00:24:52,799 --> 00:24:54,950 ignition and here is the second friction sparks obtained from steel and normal 1180 00:24:54,950 --> 00:24:54,960 sparks obtained from steel and normal 1181 00:24:54,960 --> 00:24:57,430 sparks obtained from steel and normal steel grinding operations seldom have 1182 00:24:57,430 --> 00:24:57,440 steel grinding operations seldom have 1183 00:24:57,440 --> 00:24:59,350 steel grinding operations seldom have enough size and temperature to ignite 1184 00:24:59,350 --> 00:24:59,360 enough size and temperature to ignite 1185 00:24:59,360 --> 00:25:01,510 enough size and temperature to ignite gasoline but these studies show that 1186 00:25:01,510 --> 00:25:01,520 gasoline but these studies show that 1187 00:25:01,520 --> 00:25:03,590 gasoline but these studies show that friction sparks of sufficient energy for 1188 00:25:03,590 --> 00:25:03,600 friction sparks of sufficient energy for 1189 00:25:03,600 --> 00:25:06,149 friction sparks of sufficient energy for ignition of gasoline can occur under the 1190 00:25:06,149 --> 00:25:06,159 ignition of gasoline can occur under the 1191 00:25:06,159 --> 00:25:08,070 ignition of gasoline can occur under the conditions of high friction loads which 1192 00:25:08,070 --> 00:25:08,080 conditions of high friction loads which 1193 00:25:08,080 --> 00:25:12,230 conditions of high friction loads which exist in some crashes 1194 00:25:12,230 --> 00:25:12,240 1195 00:25:12,240 --> 00:25:14,549 to summarize these results show that the 1196 00:25:14,549 --> 00:25:14,559 to summarize these results show that the 1197 00:25:14,559 --> 00:25:16,549 to summarize these results show that the ignitable vapor zones arising from 1198 00:25:16,549 --> 00:25:16,559 ignitable vapor zones arising from 1199 00:25:16,559 --> 00:25:18,310 ignitable vapor zones arising from liquid spilling in the open air are 1200 00:25:18,310 --> 00:25:18,320 liquid spilling in the open air are 1201 00:25:18,320 --> 00:25:22,630 liquid spilling in the open air are small except in wind protected areas 1202 00:25:22,630 --> 00:25:22,640 small except in wind protected areas 1203 00:25:22,640 --> 00:25:24,789 small except in wind protected areas liquid fuel spilled in the wings moves 1204 00:25:24,789 --> 00:25:24,799 liquid fuel spilled in the wings moves 1205 00:25:24,799 --> 00:25:26,630 liquid fuel spilled in the wings moves as liquid and vapor through the 1206 00:25:26,630 --> 00:25:26,640 as liquid and vapor through the 1207 00:25:26,640 --> 00:25:28,710 as liquid and vapor through the structural channels 1208 00:25:28,710 --> 00:25:28,720 structural channels 1209 00:25:28,720 --> 00:25:30,710 structural channels widespread distribution of a fuel in 1210 00:25:30,710 --> 00:25:30,720 widespread distribution of a fuel in 1211 00:25:30,720 --> 00:25:32,630 widespread distribution of a fuel in liquid form can occur by wetting 1212 00:25:32,630 --> 00:25:32,640 liquid form can occur by wetting 1213 00:25:32,640 --> 00:25:34,070 liquid form can occur by wetting conduction 1214 00:25:34,070 --> 00:25:34,080 conduction 1215 00:25:34,080 --> 00:25:35,990 conduction in contrast with a fuel mist which 1216 00:25:35,990 --> 00:25:36,000 in contrast with a fuel mist which 1217 00:25:36,000 --> 00:25:37,750 in contrast with a fuel mist which persists for only a few seconds in the 1218 00:25:37,750 --> 00:25:37,760 persists for only a few seconds in the 1219 00:25:37,760 --> 00:25:40,070 persists for only a few seconds in the crash area the fuel and liquid form on 1220 00:25:40,070 --> 00:25:40,080 crash area the fuel and liquid form on 1221 00:25:40,080 --> 00:25:41,590 crash area the fuel and liquid form on the ground and the wetted surfaces of 1222 00:25:41,590 --> 00:25:41,600 the ground and the wetted surfaces of 1223 00:25:41,600 --> 00:25:43,669 the ground and the wetted surfaces of the airplane and in the channels of the 1224 00:25:43,669 --> 00:25:43,679 the airplane and in the channels of the 1225 00:25:43,679 --> 00:25:46,070 the airplane and in the channels of the airplane structure are present for long 1226 00:25:46,070 --> 00:25:46,080 airplane structure are present for long 1227 00:25:46,080 --> 00:25:47,029 airplane structure are present for long periods 1228 00:25:47,029 --> 00:25:47,039 periods 1229 00:25:47,039 --> 00:25:48,870 periods these are the forms of fuel spillage 1230 00:25:48,870 --> 00:25:48,880 these are the forms of fuel spillage 1231 00:25:48,880 --> 00:25:50,870 these are the forms of fuel spillage that are inflamed by ignition sources 1232 00:25:50,870 --> 00:25:50,880 that are inflamed by ignition sources 1233 00:25:50,880 --> 00:25:57,269 that are inflamed by ignition sources which appear late in the crash event 1234 00:25:57,269 --> 00:25:57,279 1235 00:25:57,279 --> 00:25:59,510 the ignition of fuel pre-mixed with air 1236 00:25:59,510 --> 00:25:59,520 the ignition of fuel pre-mixed with air 1237 00:25:59,520 --> 00:26:01,510 the ignition of fuel pre-mixed with air in combustible proportions is another 1238 00:26:01,510 --> 00:26:01,520 in combustible proportions is another 1239 00:26:01,520 --> 00:26:03,909 in combustible proportions is another way in which a crash fire may begin 1240 00:26:03,909 --> 00:26:03,919 way in which a crash fire may begin 1241 00:26:03,919 --> 00:26:05,909 way in which a crash fire may begin such fuel air mixtures appear in the 1242 00:26:05,909 --> 00:26:05,919 such fuel air mixtures appear in the 1243 00:26:05,919 --> 00:26:08,230 such fuel air mixtures appear in the engine air induction system comprising 1244 00:26:08,230 --> 00:26:08,240 engine air induction system comprising 1245 00:26:08,240 --> 00:26:10,549 engine air induction system comprising the supercharger and engine intake 1246 00:26:10,549 --> 00:26:10,559 the supercharger and engine intake 1247 00:26:10,559 --> 00:26:12,789 the supercharger and engine intake manifold a rupture of the engine 1248 00:26:12,789 --> 00:26:12,799 manifold a rupture of the engine 1249 00:26:12,799 --> 00:26:14,870 manifold a rupture of the engine induction system is followed at once by 1250 00:26:14,870 --> 00:26:14,880 induction system is followed at once by 1251 00:26:14,880 --> 00:26:16,549 induction system is followed at once by release of the fuel air mixture 1252 00:26:16,549 --> 00:26:16,559 release of the fuel air mixture 1253 00:26:16,559 --> 00:26:18,710 release of the fuel air mixture contained under pressure by the engine 1254 00:26:18,710 --> 00:26:18,720 contained under pressure by the engine 1255 00:26:18,720 --> 00:26:20,070 contained under pressure by the engine supercharger 1256 00:26:20,070 --> 00:26:20,080 supercharger 1257 00:26:20,080 --> 00:26:22,149 supercharger ignition may occur by contact of this 1258 00:26:22,149 --> 00:26:22,159 ignition may occur by contact of this 1259 00:26:22,159 --> 00:26:24,149 ignition may occur by contact of this released fuel air mixture with the hot 1260 00:26:24,149 --> 00:26:24,159 released fuel air mixture with the hot 1261 00:26:24,159 --> 00:26:26,870 released fuel air mixture with the hot elements of the exhaust disposal system 1262 00:26:26,870 --> 00:26:26,880 elements of the exhaust disposal system 1263 00:26:26,880 --> 00:26:29,990 elements of the exhaust disposal system or exposed exhaust pipes by arcs and 1264 00:26:29,990 --> 00:26:30,000 or exposed exhaust pipes by arcs and 1265 00:26:30,000 --> 00:26:32,470 or exposed exhaust pipes by arcs and sparks of the electrical system or by 1266 00:26:32,470 --> 00:26:32,480 sparks of the electrical system or by 1267 00:26:32,480 --> 00:26:40,470 sparks of the electrical system or by backfire from the engine cylinders 1268 00:26:40,470 --> 00:26:40,480 1269 00:26:40,480 --> 00:26:42,549 because of the high air flow rates 1270 00:26:42,549 --> 00:26:42,559 because of the high air flow rates 1271 00:26:42,559 --> 00:26:44,549 because of the high air flow rates through the engine the cell in the early 1272 00:26:44,549 --> 00:26:44,559 through the engine the cell in the early 1273 00:26:44,559 --> 00:26:46,390 through the engine the cell in the early phases of a crash when the airplane is 1274 00:26:46,390 --> 00:26:46,400 phases of a crash when the airplane is 1275 00:26:46,400 --> 00:26:48,710 phases of a crash when the airplane is moving at high speed ignition of this 1276 00:26:48,710 --> 00:26:48,720 moving at high speed ignition of this 1277 00:26:48,720 --> 00:26:50,870 moving at high speed ignition of this released fuel air mixture must occur 1278 00:26:50,870 --> 00:26:50,880 released fuel air mixture must occur 1279 00:26:50,880 --> 00:26:53,190 released fuel air mixture must occur shortly after engine induction system 1280 00:26:53,190 --> 00:26:53,200 shortly after engine induction system 1281 00:26:53,200 --> 00:26:55,669 shortly after engine induction system failure otherwise the fuel air mixture 1282 00:26:55,669 --> 00:26:55,679 failure otherwise the fuel air mixture 1283 00:26:55,679 --> 00:26:57,909 failure otherwise the fuel air mixture is quickly swept from the nacelle by the 1284 00:26:57,909 --> 00:26:57,919 is quickly swept from the nacelle by the 1285 00:26:57,919 --> 00:27:00,710 is quickly swept from the nacelle by the airflow although the fire produced by 1286 00:27:00,710 --> 00:27:00,720 airflow although the fire produced by 1287 00:27:00,720 --> 00:27:02,549 airflow although the fire produced by the ignition of the engine induction 1288 00:27:02,549 --> 00:27:02,559 the ignition of the engine induction 1289 00:27:02,559 --> 00:27:04,870 the ignition of the engine induction system fuel is not serious in itself 1290 00:27:04,870 --> 00:27:04,880 system fuel is not serious in itself 1291 00:27:04,880 --> 00:27:06,470 system fuel is not serious in itself because of the small amount of fuel 1292 00:27:06,470 --> 00:27:06,480 because of the small amount of fuel 1293 00:27:06,480 --> 00:27:09,110 because of the small amount of fuel involved this fire can extend to other 1294 00:27:09,110 --> 00:27:09,120 involved this fire can extend to other 1295 00:27:09,120 --> 00:27:11,350 involved this fire can extend to other fuel being spilled and so set off the 1296 00:27:11,350 --> 00:27:11,360 fuel being spilled and so set off the 1297 00:27:11,360 --> 00:27:14,230 fuel being spilled and so set off the major fire in the next crash to be shown 1298 00:27:14,230 --> 00:27:14,240 major fire in the next crash to be shown 1299 00:27:14,240 --> 00:27:16,070 major fire in the next crash to be shown the engine on your right breaks out of 1300 00:27:16,070 --> 00:27:16,080 the engine on your right breaks out of 1301 00:27:16,080 --> 00:27:18,310 the engine on your right breaks out of its nacelle at the moment of impact the 1302 00:27:18,310 --> 00:27:18,320 its nacelle at the moment of impact the 1303 00:27:18,320 --> 00:27:20,310 its nacelle at the moment of impact the engine fractures along the line passing 1304 00:27:20,310 --> 00:27:20,320 engine fractures along the line passing 1305 00:27:20,320 --> 00:27:22,549 engine fractures along the line passing through the case of the supercharger the 1306 00:27:22,549 --> 00:27:22,559 through the case of the supercharger the 1307 00:27:22,559 --> 00:27:24,710 through the case of the supercharger the released fuel air mixture is ignited at 1308 00:27:24,710 --> 00:27:24,720 released fuel air mixture is ignited at 1309 00:27:24,720 --> 00:27:27,029 released fuel air mixture is ignited at once by exhaust flame issuing from the 1310 00:27:27,029 --> 00:27:27,039 once by exhaust flame issuing from the 1311 00:27:27,039 --> 00:27:31,029 once by exhaust flame issuing from the adjacent broken engine exhaust 1312 00:27:31,029 --> 00:27:31,039 adjacent broken engine exhaust 1313 00:27:31,039 --> 00:27:33,029 adjacent broken engine exhaust here the airplane approaches the crash 1314 00:27:33,029 --> 00:27:33,039 here the airplane approaches the crash 1315 00:27:33,039 --> 00:27:35,350 here the airplane approaches the crash barrier the action is shown at 1 12 1316 00:27:35,350 --> 00:27:35,360 barrier the action is shown at 1 12 1317 00:27:35,360 --> 00:27:37,750 barrier the action is shown at 1 12 normal speed watch the engine in full 1318 00:27:37,750 --> 00:27:37,760 normal speed watch the engine in full 1319 00:27:37,760 --> 00:27:40,310 normal speed watch the engine in full view snap from its mounts ignition of 1320 00:27:40,310 --> 00:27:40,320 view snap from its mounts ignition of 1321 00:27:40,320 --> 00:27:42,870 view snap from its mounts ignition of the fuel air mixture occurs at once the 1322 00:27:42,870 --> 00:27:42,880 the fuel air mixture occurs at once the 1323 00:27:42,880 --> 00:27:44,710 the fuel air mixture occurs at once the fuel being spilled adjacent to the 1324 00:27:44,710 --> 00:27:44,720 fuel being spilled adjacent to the 1325 00:27:44,720 --> 00:27:47,269 fuel being spilled adjacent to the nacelle is then ignited from this flash 1326 00:27:47,269 --> 00:27:47,279 nacelle is then ignited from this flash 1327 00:27:47,279 --> 00:27:52,630 nacelle is then ignited from this flash fire 1328 00:27:52,630 --> 00:27:52,640 1329 00:27:52,640 --> 00:27:55,029 another crash fire involving ignition of 1330 00:27:55,029 --> 00:27:55,039 another crash fire involving ignition of 1331 00:27:55,039 --> 00:27:56,789 another crash fire involving ignition of the engine induction system fuel 1332 00:27:56,789 --> 00:27:56,799 the engine induction system fuel 1333 00:27:56,799 --> 00:27:58,789 the engine induction system fuel occurred in the following sequence 1334 00:27:58,789 --> 00:27:58,799 occurred in the following sequence 1335 00:27:58,799 --> 00:28:01,110 occurred in the following sequence damage to the engine induction system on 1336 00:28:01,110 --> 00:28:01,120 damage to the engine induction system on 1337 00:28:01,120 --> 00:28:03,350 damage to the engine induction system on crash impact resulted in a fire at the 1338 00:28:03,350 --> 00:28:03,360 crash impact resulted in a fire at the 1339 00:28:03,360 --> 00:28:05,269 crash impact resulted in a fire at the nacelle in a manner similar to that 1340 00:28:05,269 --> 00:28:05,279 nacelle in a manner similar to that 1341 00:28:05,279 --> 00:28:08,310 nacelle in a manner similar to that shown in a previous crash 1342 00:28:08,310 --> 00:28:08,320 shown in a previous crash 1343 00:28:08,320 --> 00:28:10,549 shown in a previous crash fuel spilling from the broken main fuel 1344 00:28:10,549 --> 00:28:10,559 fuel spilling from the broken main fuel 1345 00:28:10,559 --> 00:28:12,870 fuel spilling from the broken main fuel line at the nacelle firewall was ignited 1346 00:28:12,870 --> 00:28:12,880 line at the nacelle firewall was ignited 1347 00:28:12,880 --> 00:28:14,789 line at the nacelle firewall was ignited by the flash fire of the engine 1348 00:28:14,789 --> 00:28:14,799 by the flash fire of the engine 1349 00:28:14,799 --> 00:28:17,190 by the flash fire of the engine induction system fuel the resulting 1350 00:28:17,190 --> 00:28:17,200 induction system fuel the resulting 1351 00:28:17,200 --> 00:28:19,430 induction system fuel the resulting flames streamed rearward over the 1352 00:28:19,430 --> 00:28:19,440 flames streamed rearward over the 1353 00:28:19,440 --> 00:28:22,389 flames streamed rearward over the nacelle and wing 1354 00:28:22,389 --> 00:28:22,399 nacelle and wing 1355 00:28:22,399 --> 00:28:24,070 nacelle and wing afterwards the fuel spilling from the 1356 00:28:24,070 --> 00:28:24,080 afterwards the fuel spilling from the 1357 00:28:24,080 --> 00:28:25,830 afterwards the fuel spilling from the wings through the ruptures cut by the 1358 00:28:25,830 --> 00:28:25,840 wings through the ruptures cut by the 1359 00:28:25,840 --> 00:28:28,310 wings through the ruptures cut by the poles at the crash barrier fanned out 1360 00:28:28,310 --> 00:28:28,320 poles at the crash barrier fanned out 1361 00:28:28,320 --> 00:28:30,470 poles at the crash barrier fanned out into the wake of the wing contact 1362 00:28:30,470 --> 00:28:30,480 into the wake of the wing contact 1363 00:28:30,480 --> 00:28:32,310 into the wake of the wing contact between the flames and the fuel took 1364 00:28:32,310 --> 00:28:32,320 between the flames and the fuel took 1365 00:28:32,320 --> 00:28:34,389 between the flames and the fuel took place to the rear of the trailing edge 1366 00:28:34,389 --> 00:28:34,399 place to the rear of the trailing edge 1367 00:28:34,399 --> 00:28:40,789 place to the rear of the trailing edge of the wing 1368 00:28:40,789 --> 00:28:40,799 1369 00:28:40,799 --> 00:28:43,110 the flames moved forward to the wing 1370 00:28:43,110 --> 00:28:43,120 the flames moved forward to the wing 1371 00:28:43,120 --> 00:28:44,630 the flames moved forward to the wing through the trailing fuel as the 1372 00:28:44,630 --> 00:28:44,640 through the trailing fuel as the 1373 00:28:44,640 --> 00:28:46,870 through the trailing fuel as the airplane speed fell below the flame 1374 00:28:46,870 --> 00:28:46,880 airplane speed fell below the flame 1375 00:28:46,880 --> 00:28:51,510 airplane speed fell below the flame propagation speed 1376 00:28:51,510 --> 00:28:51,520 1377 00:28:51,520 --> 00:28:53,590 now watch this fire setting mechanism in 1378 00:28:53,590 --> 00:28:53,600 now watch this fire setting mechanism in 1379 00:28:53,600 --> 00:28:55,990 now watch this fire setting mechanism in the next movie sequence at normal speed 1380 00:28:55,990 --> 00:28:56,000 the next movie sequence at normal speed 1381 00:28:56,000 --> 00:28:58,310 the next movie sequence at normal speed watch the nacelle and note the forward 1382 00:28:58,310 --> 00:28:58,320 watch the nacelle and note the forward 1383 00:28:58,320 --> 00:29:03,590 watch the nacelle and note the forward movement of the flame 1384 00:29:03,590 --> 00:29:03,600 1385 00:29:03,600 --> 00:29:05,510 the research up to this point resulted 1386 00:29:05,510 --> 00:29:05,520 the research up to this point resulted 1387 00:29:05,520 --> 00:29:07,190 the research up to this point resulted in an understanding of the ignition 1388 00:29:07,190 --> 00:29:07,200 in an understanding of the ignition 1389 00:29:07,200 --> 00:29:09,350 in an understanding of the ignition sources involved in a series of crash 1390 00:29:09,350 --> 00:29:09,360 sources involved in a series of crash 1391 00:29:09,360 --> 00:29:12,070 sources involved in a series of crash fires and also how the fuel in the mist 1392 00:29:12,070 --> 00:29:12,080 fires and also how the fuel in the mist 1393 00:29:12,080 --> 00:29:14,470 fires and also how the fuel in the mist liquid and vapor forms moved from the 1394 00:29:14,470 --> 00:29:14,480 liquid and vapor forms moved from the 1395 00:29:14,480 --> 00:29:16,870 liquid and vapor forms moved from the spillage point to the ignition sources 1396 00:29:16,870 --> 00:29:16,880 spillage point to the ignition sources 1397 00:29:16,880 --> 00:29:19,110 spillage point to the ignition sources however these ignition sources revealed 1398 00:29:19,110 --> 00:29:19,120 however these ignition sources revealed 1399 00:29:19,120 --> 00:29:21,350 however these ignition sources revealed so far usually produced fires within a 1400 00:29:21,350 --> 00:29:21,360 so far usually produced fires within a 1401 00:29:21,360 --> 00:29:23,830 so far usually produced fires within a few seconds after crash impact 1402 00:29:23,830 --> 00:29:23,840 few seconds after crash impact 1403 00:29:23,840 --> 00:29:25,750 few seconds after crash impact because it was felt these early fires 1404 00:29:25,750 --> 00:29:25,760 because it was felt these early fires 1405 00:29:25,760 --> 00:29:28,070 because it was felt these early fires might mask other ways in which fire can 1406 00:29:28,070 --> 00:29:28,080 might mask other ways in which fire can 1407 00:29:28,080 --> 00:29:30,710 might mask other ways in which fire can occur the known ignition sources were 1408 00:29:30,710 --> 00:29:30,720 occur the known ignition sources were 1409 00:29:30,720 --> 00:29:38,149 occur the known ignition sources were inerted by experimental means 1410 00:29:38,149 --> 00:29:38,159 1411 00:29:38,159 --> 00:29:40,549 the parts of the inerting system used in 1412 00:29:40,549 --> 00:29:40,559 the parts of the inerting system used in 1413 00:29:40,559 --> 00:29:42,070 the parts of the inerting system used in this investigation are shown 1414 00:29:42,070 --> 00:29:42,080 this investigation are shown 1415 00:29:42,080 --> 00:29:44,630 this investigation are shown diagrammatically on this chart 1416 00:29:44,630 --> 00:29:44,640 diagrammatically on this chart 1417 00:29:44,640 --> 00:29:46,870 diagrammatically on this chart here are the main parts of a typical 1418 00:29:46,870 --> 00:29:46,880 here are the main parts of a typical 1419 00:29:46,880 --> 00:29:49,430 here are the main parts of a typical engine nacelle to prevent the appearance 1420 00:29:49,430 --> 00:29:49,440 engine nacelle to prevent the appearance 1421 00:29:49,440 --> 00:29:51,350 engine nacelle to prevent the appearance of flames at the engine inlet and 1422 00:29:51,350 --> 00:29:51,360 of flames at the engine inlet and 1423 00:29:51,360 --> 00:29:53,909 of flames at the engine inlet and exhaust outlet fuel system shutoff 1424 00:29:53,909 --> 00:29:53,919 exhaust outlet fuel system shutoff 1425 00:29:53,919 --> 00:29:56,630 exhaust outlet fuel system shutoff valves are installed at the engine 1426 00:29:56,630 --> 00:29:56,640 valves are installed at the engine 1427 00:29:56,640 --> 00:29:59,029 valves are installed at the engine and the firewall to stop the fuel flow 1428 00:29:59,029 --> 00:29:59,039 and the firewall to stop the fuel flow 1429 00:29:59,039 --> 00:30:01,029 and the firewall to stop the fuel flow following crash impact 1430 00:30:01,029 --> 00:30:01,039 following crash impact 1431 00:30:01,039 --> 00:30:03,029 following crash impact one valve stops the fuel flow to the 1432 00:30:03,029 --> 00:30:03,039 one valve stops the fuel flow to the 1433 00:30:03,039 --> 00:30:04,870 one valve stops the fuel flow to the engine the other prevents the fuel 1434 00:30:04,870 --> 00:30:04,880 engine the other prevents the fuel 1435 00:30:04,880 --> 00:30:07,830 engine the other prevents the fuel spillage into the nacelle several pounds 1436 00:30:07,830 --> 00:30:07,840 spillage into the nacelle several pounds 1437 00:30:07,840 --> 00:30:09,990 spillage into the nacelle several pounds of suitable fire extinguishing agent 1438 00:30:09,990 --> 00:30:10,000 of suitable fire extinguishing agent 1439 00:30:10,000 --> 00:30:12,470 of suitable fire extinguishing agent discharged uniformly in the engine inlet 1440 00:30:12,470 --> 00:30:12,480 discharged uniformly in the engine inlet 1441 00:30:12,480 --> 00:30:15,350 discharged uniformly in the engine inlet air to inert the contents of the engine 1442 00:30:15,350 --> 00:30:15,360 air to inert the contents of the engine 1443 00:30:15,360 --> 00:30:17,350 air to inert the contents of the engine during the period of time required for 1444 00:30:17,350 --> 00:30:17,360 during the period of time required for 1445 00:30:17,360 --> 00:30:22,070 during the period of time required for the valves to stop the fuel flow 1446 00:30:22,070 --> 00:30:22,080 1447 00:30:22,080 --> 00:30:24,310 electrical system switch shuts down the 1448 00:30:24,310 --> 00:30:24,320 electrical system switch shuts down the 1449 00:30:24,320 --> 00:30:27,029 electrical system switch shuts down the airplane battery and generator circuits 1450 00:30:27,029 --> 00:30:27,039 airplane battery and generator circuits 1451 00:30:27,039 --> 00:30:28,710 airplane battery and generator circuits the ignition system continues to 1452 00:30:28,710 --> 00:30:28,720 the ignition system continues to 1453 00:30:28,720 --> 00:30:30,710 the ignition system continues to function so that fuel passing into the 1454 00:30:30,710 --> 00:30:30,720 function so that fuel passing into the 1455 00:30:30,720 --> 00:30:32,389 function so that fuel passing into the engine will be burned in the normal 1456 00:30:32,389 --> 00:30:32,399 engine will be burned in the normal 1457 00:30:32,399 --> 00:30:34,950 engine will be burned in the normal manner in case the fuel shut off valves 1458 00:30:34,950 --> 00:30:34,960 manner in case the fuel shut off valves 1459 00:30:34,960 --> 00:30:37,110 manner in case the fuel shut off valves and the fire extinguishing agent system 1460 00:30:37,110 --> 00:30:37,120 and the fire extinguishing agent system 1461 00:30:37,120 --> 00:30:40,070 and the fire extinguishing agent system at the engine inlet are slow to function 1462 00:30:40,070 --> 00:30:40,080 at the engine inlet are slow to function 1463 00:30:40,080 --> 00:30:42,389 at the engine inlet are slow to function normal engine exhaust is less likely to 1464 00:30:42,389 --> 00:30:42,399 normal engine exhaust is less likely to 1465 00:30:42,399 --> 00:30:45,110 normal engine exhaust is less likely to start a fire than tail pipe flame which 1466 00:30:45,110 --> 00:30:45,120 start a fire than tail pipe flame which 1467 00:30:45,120 --> 00:30:47,269 start a fire than tail pipe flame which forms that when the fuel charge passes 1468 00:30:47,269 --> 00:30:47,279 forms that when the fuel charge passes 1469 00:30:47,279 --> 00:30:49,909 forms that when the fuel charge passes through the engine cylinder unburned and 1470 00:30:49,909 --> 00:30:49,919 through the engine cylinder unburned and 1471 00:30:49,919 --> 00:30:52,070 through the engine cylinder unburned and is later ignited in the hot exhaust 1472 00:30:52,070 --> 00:30:52,080 is later ignited in the hot exhaust 1473 00:30:52,080 --> 00:30:53,190 is later ignited in the hot exhaust system 1474 00:30:53,190 --> 00:30:53,200 system 1475 00:30:53,200 --> 00:30:55,269 system in order to prevent ignition on the hot 1476 00:30:55,269 --> 00:30:55,279 in order to prevent ignition on the hot 1477 00:30:55,279 --> 00:30:57,510 in order to prevent ignition on the hot metal of the exhaust system a water 1478 00:30:57,510 --> 00:30:57,520 metal of the exhaust system a water 1479 00:30:57,520 --> 00:30:59,990 metal of the exhaust system a water spray is used to cool all of the exposed 1480 00:30:59,990 --> 00:31:00,000 spray is used to cool all of the exposed 1481 00:31:00,000 --> 00:31:01,750 spray is used to cool all of the exposed metal which is hot enough to ignite the 1482 00:31:01,750 --> 00:31:01,760 metal which is hot enough to ignite the 1483 00:31:01,760 --> 00:31:04,230 metal which is hot enough to ignite the combustible in a few seconds needed to 1484 00:31:04,230 --> 00:31:04,240 combustible in a few seconds needed to 1485 00:31:04,240 --> 00:31:06,389 combustible in a few seconds needed to cool the metal to safe temperatures and 1486 00:31:06,389 --> 00:31:06,399 cool the metal to safe temperatures and 1487 00:31:06,399 --> 00:31:08,789 cool the metal to safe temperatures and inert atmosphere of steam generated by 1488 00:31:08,789 --> 00:31:08,799 inert atmosphere of steam generated by 1489 00:31:08,799 --> 00:31:10,470 inert atmosphere of steam generated by the water evaporating from the metal 1490 00:31:10,470 --> 00:31:10,480 the water evaporating from the metal 1491 00:31:10,480 --> 00:31:13,190 the water evaporating from the metal itself shrouds this potential ignition 1492 00:31:13,190 --> 00:31:13,200 itself shrouds this potential ignition 1493 00:31:13,200 --> 00:31:15,669 itself shrouds this potential ignition source to render it impotent the portion 1494 00:31:15,669 --> 00:31:15,679 source to render it impotent the portion 1495 00:31:15,679 --> 00:31:17,590 source to render it impotent the portion of the water spray system which services 1496 00:31:17,590 --> 00:31:17,600 of the water spray system which services 1497 00:31:17,600 --> 00:31:19,909 of the water spray system which services the exhaust collector ring is this 1498 00:31:19,909 --> 00:31:19,919 the exhaust collector ring is this 1499 00:31:19,919 --> 00:31:22,230 the exhaust collector ring is this three-quarter inch diameter tubing bent 1500 00:31:22,230 --> 00:31:22,240 three-quarter inch diameter tubing bent 1501 00:31:22,240 --> 00:31:24,310 three-quarter inch diameter tubing bent to conform approximately to the shape of 1502 00:31:24,310 --> 00:31:24,320 to conform approximately to the shape of 1503 00:31:24,320 --> 00:31:26,710 to conform approximately to the shape of the collector ring the exhaust system 1504 00:31:26,710 --> 00:31:26,720 the collector ring the exhaust system 1505 00:31:26,720 --> 00:31:28,789 the collector ring the exhaust system receives water over its entire surface 1506 00:31:28,789 --> 00:31:28,799 receives water over its entire surface 1507 00:31:28,799 --> 00:31:30,630 receives water over its entire surface from its spray nozzle 1508 00:31:30,630 --> 00:31:30,640 from its spray nozzle 1509 00:31:30,640 --> 00:31:32,630 from its spray nozzle the effectiveness of the water spray in 1510 00:31:32,630 --> 00:31:32,640 the effectiveness of the water spray in 1511 00:31:32,640 --> 00:31:34,789 the effectiveness of the water spray in preventing ignition on the hot exhaust 1512 00:31:34,789 --> 00:31:34,799 preventing ignition on the hot exhaust 1513 00:31:34,799 --> 00:31:36,549 preventing ignition on the hot exhaust is demonstrated by the rapidity with 1514 00:31:36,549 --> 00:31:36,559 is demonstrated by the rapidity with 1515 00:31:36,559 --> 00:31:39,029 is demonstrated by the rapidity with which a continuously fed oil fire 1516 00:31:39,029 --> 00:31:39,039 which a continuously fed oil fire 1517 00:31:39,039 --> 00:31:40,710 which a continuously fed oil fire burning from the exhaust system is 1518 00:31:40,710 --> 00:31:40,720 burning from the exhaust system is 1519 00:31:40,720 --> 00:31:43,029 burning from the exhaust system is extinguished by the water spray 1520 00:31:43,029 --> 00:31:43,039 extinguished by the water spray 1521 00:31:43,039 --> 00:31:44,870 extinguished by the water spray notice how the application of the water 1522 00:31:44,870 --> 00:31:44,880 notice how the application of the water 1523 00:31:44,880 --> 00:31:47,190 notice how the application of the water spray extinguishes the fire almost at 1524 00:31:47,190 --> 00:31:47,200 spray extinguishes the fire almost at 1525 00:31:47,200 --> 00:31:59,190 spray extinguishes the fire almost at once 1526 00:31:59,190 --> 00:31:59,200 1527 00:31:59,200 --> 00:32:01,110 this crash is typical of the results 1528 00:32:01,110 --> 00:32:01,120 this crash is typical of the results 1529 00:32:01,120 --> 00:32:03,190 this crash is typical of the results obtained with five aircraft equipped 1530 00:32:03,190 --> 00:32:03,200 obtained with five aircraft equipped 1531 00:32:03,200 --> 00:32:05,110 obtained with five aircraft equipped with the experimental inerting system 1532 00:32:05,110 --> 00:32:05,120 with the experimental inerting system 1533 00:32:05,120 --> 00:32:06,950 with the experimental inerting system just described which is arranged to be 1534 00:32:06,950 --> 00:32:06,960 just described which is arranged to be 1535 00:32:06,960 --> 00:32:09,029 just described which is arranged to be actuated as soon as possible after a 1536 00:32:09,029 --> 00:32:09,039 actuated as soon as possible after a 1537 00:32:09,039 --> 00:32:11,430 actuated as soon as possible after a crash impacted the barrier 1538 00:32:11,430 --> 00:32:11,440 crash impacted the barrier 1539 00:32:11,440 --> 00:32:13,509 crash impacted the barrier the only visible sign of the functioning 1540 00:32:13,509 --> 00:32:13,519 the only visible sign of the functioning 1541 00:32:13,519 --> 00:32:15,350 the only visible sign of the functioning of the inerting system is the steam 1542 00:32:15,350 --> 00:32:15,360 of the inerting system is the steam 1543 00:32:15,360 --> 00:32:17,990 of the inerting system is the steam evaporating from the hot exhaust system 1544 00:32:17,990 --> 00:32:18,000 evaporating from the hot exhaust system 1545 00:32:18,000 --> 00:32:19,669 evaporating from the hot exhaust system this is the steam which was visible in 1546 00:32:19,669 --> 00:32:19,679 this is the steam which was visible in 1547 00:32:19,679 --> 00:32:22,149 this is the steam which was visible in some of the preceding pictures the fuel 1548 00:32:22,149 --> 00:32:22,159 some of the preceding pictures the fuel 1549 00:32:22,159 --> 00:32:24,149 some of the preceding pictures the fuel here has been dyed red 1550 00:32:24,149 --> 00:32:24,159 here has been dyed red 1551 00:32:24,159 --> 00:32:26,070 here has been dyed red see the dust being raised by the 1552 00:32:26,070 --> 00:32:26,080 see the dust being raised by the 1553 00:32:26,080 --> 00:32:28,070 see the dust being raised by the airplane fuselage skidding along the 1554 00:32:28,070 --> 00:32:28,080 airplane fuselage skidding along the 1555 00:32:28,080 --> 00:32:30,789 airplane fuselage skidding along the ground this dust plays an important part 1556 00:32:30,789 --> 00:32:30,799 ground this dust plays an important part 1557 00:32:30,799 --> 00:32:32,549 ground this dust plays an important part in starting fires to be described 1558 00:32:32,549 --> 00:32:32,559 in starting fires to be described 1559 00:32:32,559 --> 00:32:33,590 in starting fires to be described shortly 1560 00:32:33,590 --> 00:32:33,600 shortly 1561 00:32:33,600 --> 00:32:35,830 shortly this experimental inerting system used 1562 00:32:35,830 --> 00:32:35,840 this experimental inerting system used 1563 00:32:35,840 --> 00:32:37,830 this experimental inerting system used in this crash was devised solely for 1564 00:32:37,830 --> 00:32:37,840 in this crash was devised solely for 1565 00:32:37,840 --> 00:32:39,990 in this crash was devised solely for studies of this kind and does not 1566 00:32:39,990 --> 00:32:40,000 studies of this kind and does not 1567 00:32:40,000 --> 00:32:42,070 studies of this kind and does not incorporate the considerations of weight 1568 00:32:42,070 --> 00:32:42,080 incorporate the considerations of weight 1569 00:32:42,080 --> 00:32:44,070 incorporate the considerations of weight and bulk which would be involved in 1570 00:32:44,070 --> 00:32:44,080 and bulk which would be involved in 1571 00:32:44,080 --> 00:32:45,830 and bulk which would be involved in inerting equipment for operating 1572 00:32:45,830 --> 00:32:45,840 inerting equipment for operating 1573 00:32:45,840 --> 00:32:47,190 inerting equipment for operating aircraft 1574 00:32:47,190 --> 00:32:47,200 aircraft 1575 00:32:47,200 --> 00:32:49,190 aircraft in this phase of the research in which 1576 00:32:49,190 --> 00:32:49,200 in this phase of the research in which 1577 00:32:49,200 --> 00:32:51,029 in this phase of the research in which aircraft carrying the experimental 1578 00:32:51,029 --> 00:32:51,039 aircraft carrying the experimental 1579 00:32:51,039 --> 00:32:52,789 aircraft carrying the experimental inerting system were subjected to 1580 00:32:52,789 --> 00:32:52,799 inerting system were subjected to 1581 00:32:52,799 --> 00:32:56,070 inerting system were subjected to moderate damage upon crash impact no new 1582 00:32:56,070 --> 00:32:56,080 moderate damage upon crash impact no new 1583 00:32:56,080 --> 00:32:58,470 moderate damage upon crash impact no new ignition sources were revealed 1584 00:32:58,470 --> 00:32:58,480 ignition sources were revealed 1585 00:32:58,480 --> 00:33:00,870 ignition sources were revealed after five crashes in which no fires 1586 00:33:00,870 --> 00:33:00,880 after five crashes in which no fires 1587 00:33:00,880 --> 00:33:02,630 after five crashes in which no fires were obtained and no new ignition 1588 00:33:02,630 --> 00:33:02,640 were obtained and no new ignition 1589 00:33:02,640 --> 00:33:04,630 were obtained and no new ignition sources were observed the crash 1590 00:33:04,630 --> 00:33:04,640 sources were observed the crash 1591 00:33:04,640 --> 00:33:06,789 sources were observed the crash circumstances were modified in an effort 1592 00:33:06,789 --> 00:33:06,799 circumstances were modified in an effort 1593 00:33:06,799 --> 00:33:08,870 circumstances were modified in an effort to learn other ways in which fires may 1594 00:33:08,870 --> 00:33:08,880 to learn other ways in which fires may 1595 00:33:08,880 --> 00:33:12,070 to learn other ways in which fires may occur in order to learn whether ignition 1596 00:33:12,070 --> 00:33:12,080 occur in order to learn whether ignition 1597 00:33:12,080 --> 00:33:14,149 occur in order to learn whether ignition sources may be created by the tearing 1598 00:33:14,149 --> 00:33:14,159 sources may be created by the tearing 1599 00:33:14,159 --> 00:33:15,990 sources may be created by the tearing and twisting of the airplane structure 1600 00:33:15,990 --> 00:33:16,000 and twisting of the airplane structure 1601 00:33:16,000 --> 00:33:17,750 and twisting of the airplane structure in a severe crash 1602 00:33:17,750 --> 00:33:17,760 in a severe crash 1603 00:33:17,760 --> 00:33:19,590 in a severe crash the forward portion of the fuselage 1604 00:33:19,590 --> 00:33:19,600 the forward portion of the fuselage 1605 00:33:19,600 --> 00:33:21,350 the forward portion of the fuselage structure was crushed along this 1606 00:33:21,350 --> 00:33:21,360 structure was crushed along this 1607 00:33:21,360 --> 00:33:25,029 structure was crushed along this inclined line in one crash as before the 1608 00:33:25,029 --> 00:33:25,039 inclined line in one crash as before the 1609 00:33:25,039 --> 00:33:26,870 inclined line in one crash as before the nacelles carried the experimental 1610 00:33:26,870 --> 00:33:26,880 nacelles carried the experimental 1611 00:33:26,880 --> 00:33:28,870 nacelles carried the experimental inerting system in the pictures which 1612 00:33:28,870 --> 00:33:28,880 inerting system in the pictures which 1613 00:33:28,880 --> 00:33:30,950 inerting system in the pictures which follow note the complete collapse of 1614 00:33:30,950 --> 00:33:30,960 follow note the complete collapse of 1615 00:33:30,960 --> 00:33:32,870 follow note the complete collapse of this fuselage force structure bringing 1616 00:33:32,870 --> 00:33:32,880 this fuselage force structure bringing 1617 00:33:32,880 --> 00:33:34,870 this fuselage force structure bringing the wings to ground level and the 1618 00:33:34,870 --> 00:33:34,880 the wings to ground level and the 1619 00:33:34,880 --> 00:33:36,630 the wings to ground level and the resulting wetting of this structure by 1620 00:33:36,630 --> 00:33:36,640 resulting wetting of this structure by 1621 00:33:36,640 --> 00:33:42,870 resulting wetting of this structure by the released fuel 1622 00:33:42,870 --> 00:33:42,880 1623 00:33:42,880 --> 00:33:44,710 while no fire occurred around the 1624 00:33:44,710 --> 00:33:44,720 while no fire occurred around the 1625 00:33:44,720 --> 00:33:46,870 while no fire occurred around the crushed structure ignition of the fuel 1626 00:33:46,870 --> 00:33:46,880 crushed structure ignition of the fuel 1627 00:33:46,880 --> 00:33:49,110 crushed structure ignition of the fuel did occur in the fuel wetted wake of the 1628 00:33:49,110 --> 00:33:49,120 did occur in the fuel wetted wake of the 1629 00:33:49,120 --> 00:33:51,350 did occur in the fuel wetted wake of the airplane the ignition source was an 1630 00:33:51,350 --> 00:33:51,360 airplane the ignition source was an 1631 00:33:51,360 --> 00:33:53,590 airplane the ignition source was an electric spark discharging to the ground 1632 00:33:53,590 --> 00:33:53,600 electric spark discharging to the ground 1633 00:33:53,600 --> 00:33:55,990 electric spark discharging to the ground from the landing gear strut which broke 1634 00:33:55,990 --> 00:33:56,000 from the landing gear strut which broke 1635 00:33:56,000 --> 00:33:58,070 from the landing gear strut which broke off in the crash and tumbled in the wake 1636 00:33:58,070 --> 00:33:58,080 off in the crash and tumbled in the wake 1637 00:33:58,080 --> 00:33:59,750 off in the crash and tumbled in the wake of the airplane 1638 00:33:59,750 --> 00:33:59,760 of the airplane 1639 00:33:59,760 --> 00:34:01,830 of the airplane here the airplane approaches the crash 1640 00:34:01,830 --> 00:34:01,840 here the airplane approaches the crash 1641 00:34:01,840 --> 00:34:04,149 here the airplane approaches the crash barrier upon impact with the ground the 1642 00:34:04,149 --> 00:34:04,159 barrier upon impact with the ground the 1643 00:34:04,159 --> 00:34:06,389 barrier upon impact with the ground the forward structure collapses the action 1644 00:34:06,389 --> 00:34:06,399 forward structure collapses the action 1645 00:34:06,399 --> 00:34:09,109 forward structure collapses the action here is slowed to one-fifth normal speed 1646 00:34:09,109 --> 00:34:09,119 here is slowed to one-fifth normal speed 1647 00:34:09,119 --> 00:34:11,109 here is slowed to one-fifth normal speed now watch the wheel strut tumbling in 1648 00:34:11,109 --> 00:34:11,119 now watch the wheel strut tumbling in 1649 00:34:11,119 --> 00:34:12,950 now watch the wheel strut tumbling in the wake of the airplane and observe the 1650 00:34:12,950 --> 00:34:12,960 the wake of the airplane and observe the 1651 00:34:12,960 --> 00:34:15,190 the wake of the airplane and observe the ignition which occurs when the metal end 1652 00:34:15,190 --> 00:34:15,200 ignition which occurs when the metal end 1653 00:34:15,200 --> 00:34:17,349 ignition which occurs when the metal end of the strut approaches the ground the 1654 00:34:17,349 --> 00:34:17,359 of the strut approaches the ground the 1655 00:34:17,359 --> 00:34:19,190 of the strut approaches the ground the fire spreads through the fuel in the 1656 00:34:19,190 --> 00:34:19,200 fire spreads through the fuel in the 1657 00:34:19,200 --> 00:34:21,510 fire spreads through the fuel in the airplane wake there is no evidence of 1658 00:34:21,510 --> 00:34:21,520 airplane wake there is no evidence of 1659 00:34:21,520 --> 00:34:23,030 airplane wake there is no evidence of other ignition resulting from the 1660 00:34:23,030 --> 00:34:23,040 other ignition resulting from the 1661 00:34:23,040 --> 00:34:25,349 other ignition resulting from the destruction of the fuselage structure or 1662 00:34:25,349 --> 00:34:25,359 destruction of the fuselage structure or 1663 00:34:25,359 --> 00:34:28,629 destruction of the fuselage structure or the inerted engine the cells the igniter 1664 00:34:28,629 --> 00:34:28,639 the inerted engine the cells the igniter 1665 00:34:28,639 --> 00:34:30,149 the inerted engine the cells the igniter in this instance proved to be an 1666 00:34:30,149 --> 00:34:30,159 in this instance proved to be an 1667 00:34:30,159 --> 00:34:32,069 in this instance proved to be an electric spark discharging from the 1668 00:34:32,069 --> 00:34:32,079 electric spark discharging from the 1669 00:34:32,079 --> 00:34:34,389 electric spark discharging from the landing gear strut to the ground the 1670 00:34:34,389 --> 00:34:34,399 landing gear strut to the ground the 1671 00:34:34,399 --> 00:34:36,310 landing gear strut to the ground the necessary electrical potential on the 1672 00:34:36,310 --> 00:34:36,320 necessary electrical potential on the 1673 00:34:36,320 --> 00:34:38,550 necessary electrical potential on the strut was generated in its passage 1674 00:34:38,550 --> 00:34:38,560 strut was generated in its passage 1675 00:34:38,560 --> 00:34:40,470 strut was generated in its passage through the dust and fuel mist in the 1676 00:34:40,470 --> 00:34:40,480 through the dust and fuel mist in the 1677 00:34:40,480 --> 00:34:47,510 through the dust and fuel mist in the wake of the crashed airplane 1678 00:34:47,510 --> 00:34:47,520 1679 00:34:47,520 --> 00:34:49,669 ground studies were conducted by blowing 1680 00:34:49,669 --> 00:34:49,679 ground studies were conducted by blowing 1681 00:34:49,679 --> 00:34:52,230 ground studies were conducted by blowing dust and fuel over a landing gear strut 1682 00:34:52,230 --> 00:34:52,240 dust and fuel over a landing gear strut 1683 00:34:52,240 --> 00:34:54,069 dust and fuel over a landing gear strut and measuring the electrical potential 1684 00:34:54,069 --> 00:34:54,079 and measuring the electrical potential 1685 00:34:54,079 --> 00:34:55,990 and measuring the electrical potential built up on the surface of the landing 1686 00:34:55,990 --> 00:34:56,000 built up on the surface of the landing 1687 00:34:56,000 --> 00:34:58,470 built up on the surface of the landing gear here is the landing gear strut 1688 00:34:58,470 --> 00:34:58,480 gear here is the landing gear strut 1689 00:34:58,480 --> 00:35:01,030 gear here is the landing gear strut electrically insulated from its supports 1690 00:35:01,030 --> 00:35:01,040 electrically insulated from its supports 1691 00:35:01,040 --> 00:35:03,109 electrically insulated from its supports when dust is introduced into the air 1692 00:35:03,109 --> 00:35:03,119 when dust is introduced into the air 1693 00:35:03,119 --> 00:35:05,190 when dust is introduced into the air blowing over the strut at speeds equal 1694 00:35:05,190 --> 00:35:05,200 blowing over the strut at speeds equal 1695 00:35:05,200 --> 00:35:06,870 blowing over the strut at speeds equal to that of the strut moving through the 1696 00:35:06,870 --> 00:35:06,880 to that of the strut moving through the 1697 00:35:06,880 --> 00:35:09,510 to that of the strut moving through the air in the crash potentials in excess of 1698 00:35:09,510 --> 00:35:09,520 air in the crash potentials in excess of 1699 00:35:09,520 --> 00:35:11,430 air in the crash potentials in excess of twenty thousand volts are generated on 1700 00:35:11,430 --> 00:35:11,440 twenty thousand volts are generated on 1701 00:35:11,440 --> 00:35:13,829 twenty thousand volts are generated on the strut almost at once 1702 00:35:13,829 --> 00:35:13,839 the strut almost at once 1703 00:35:13,839 --> 00:35:16,230 the strut almost at once this voltage applied across a spark gap 1704 00:35:16,230 --> 00:35:16,240 this voltage applied across a spark gap 1705 00:35:16,240 --> 00:35:18,710 this voltage applied across a spark gap located in this small pan containing a 1706 00:35:18,710 --> 00:35:18,720 located in this small pan containing a 1707 00:35:18,720 --> 00:35:20,790 located in this small pan containing a pool of gasoline produces ignition of 1708 00:35:20,790 --> 00:35:20,800 pool of gasoline produces ignition of 1709 00:35:20,800 --> 00:35:23,430 pool of gasoline produces ignition of the gasoline 1710 00:35:23,430 --> 00:35:23,440 the gasoline 1711 00:35:23,440 --> 00:35:27,030 the gasoline here is the flaming gasoline 1712 00:35:27,030 --> 00:35:27,040 here is the flaming gasoline 1713 00:35:27,040 --> 00:35:29,030 here is the flaming gasoline in the last crash of this series the 1714 00:35:29,030 --> 00:35:29,040 in the last crash of this series the 1715 00:35:29,040 --> 00:35:31,349 in the last crash of this series the effect of an airplane ground loop on the 1716 00:35:31,349 --> 00:35:31,359 effect of an airplane ground loop on the 1717 00:35:31,359 --> 00:35:33,270 effect of an airplane ground loop on the distribution of the spill fuel was 1718 00:35:33,270 --> 00:35:33,280 distribution of the spill fuel was 1719 00:35:33,280 --> 00:35:35,829 distribution of the spill fuel was studied watch how the airplane ground 1720 00:35:35,829 --> 00:35:35,839 studied watch how the airplane ground 1721 00:35:35,839 --> 00:35:38,550 studied watch how the airplane ground loops as one landing gear is torn away 1722 00:35:38,550 --> 00:35:38,560 loops as one landing gear is torn away 1723 00:35:38,560 --> 00:35:40,470 loops as one landing gear is torn away the ground loop places the airplane and 1724 00:35:40,470 --> 00:35:40,480 the ground loop places the airplane and 1725 00:35:40,480 --> 00:35:43,270 the ground loop places the airplane and the fuel spray the fuselage wing and the 1726 00:35:43,270 --> 00:35:43,280 the fuel spray the fuselage wing and the 1727 00:35:43,280 --> 00:35:45,190 the fuel spray the fuselage wing and the cell on the right side of the airplane 1728 00:35:45,190 --> 00:35:45,200 cell on the right side of the airplane 1729 00:35:45,200 --> 00:35:47,750 cell on the right side of the airplane are wetted heavily with fuel because the 1730 00:35:47,750 --> 00:35:47,760 are wetted heavily with fuel because the 1731 00:35:47,760 --> 00:35:50,069 are wetted heavily with fuel because the inerting system carried on this airplane 1732 00:35:50,069 --> 00:35:50,079 inerting system carried on this airplane 1733 00:35:50,079 --> 00:35:52,630 inerting system carried on this airplane functioned properly and no new ignition 1734 00:35:52,630 --> 00:35:52,640 functioned properly and no new ignition 1735 00:35:52,640 --> 00:35:55,990 functioned properly and no new ignition sources appeared no fires occurred 1736 00:35:55,990 --> 00:35:56,000 sources appeared no fires occurred 1737 00:35:56,000 --> 00:35:57,910 sources appeared no fires occurred and now here's a summary of the crash 1738 00:35:57,910 --> 00:35:57,920 and now here's a summary of the crash 1739 00:35:57,920 --> 00:36:00,310 and now here's a summary of the crash fire research from two lewis flight 1740 00:36:00,310 --> 00:36:00,320 fire research from two lewis flight 1741 00:36:00,320 --> 00:36:02,790 fire research from two lewis flight propulsion laboratory scientists irving 1742 00:36:02,790 --> 00:36:02,800 propulsion laboratory scientists irving 1743 00:36:02,800 --> 00:36:04,710 propulsion laboratory scientists irving pinkel associate chief of the physics 1744 00:36:04,710 --> 00:36:04,720 pinkel associate chief of the physics 1745 00:36:04,720 --> 00:36:07,109 pinkel associate chief of the physics division and merit preston chief of the 1746 00:36:07,109 --> 00:36:07,119 division and merit preston chief of the 1747 00:36:07,119 --> 00:36:11,109 division and merit preston chief of the flight research branch mr pinkle 1748 00:36:11,109 --> 00:36:11,119 flight research branch mr pinkle 1749 00:36:11,119 --> 00:36:13,430 flight research branch mr pinkle the results of this work indicate that 1750 00:36:13,430 --> 00:36:13,440 the results of this work indicate that 1751 00:36:13,440 --> 00:36:15,349 the results of this work indicate that significant reduction in crash fire 1752 00:36:15,349 --> 00:36:15,359 significant reduction in crash fire 1753 00:36:15,359 --> 00:36:17,589 significant reduction in crash fire hazard can be realized by design 1754 00:36:17,589 --> 00:36:17,599 hazard can be realized by design 1755 00:36:17,599 --> 00:36:18,630 hazard can be realized by design measures 1756 00:36:18,630 --> 00:36:18,640 measures 1757 00:36:18,640 --> 00:36:22,390 measures that increase the span wise and forward 1758 00:36:22,390 --> 00:36:22,400 that increase the span wise and forward 1759 00:36:22,400 --> 00:36:24,950 that increase the span wise and forward distance and the elevation of the 1760 00:36:24,950 --> 00:36:24,960 distance and the elevation of the 1761 00:36:24,960 --> 00:36:28,150 distance and the elevation of the engines with respect to the fuel storage 1762 00:36:28,150 --> 00:36:28,160 engines with respect to the fuel storage 1763 00:36:28,160 --> 00:36:30,069 engines with respect to the fuel storage this trend in airplane component 1764 00:36:30,069 --> 00:36:30,079 this trend in airplane component 1765 00:36:30,079 --> 00:36:32,470 this trend in airplane component arrangement decreases the likelihood of 1766 00:36:32,470 --> 00:36:32,480 arrangement decreases the likelihood of 1767 00:36:32,480 --> 00:36:35,349 arrangement decreases the likelihood of contact between the fuel mist 1768 00:36:35,349 --> 00:36:35,359 contact between the fuel mist 1769 00:36:35,359 --> 00:36:37,589 contact between the fuel mist and the many ignition sources located at 1770 00:36:37,589 --> 00:36:37,599 and the many ignition sources located at 1771 00:36:37,599 --> 00:36:38,829 and the many ignition sources located at the engine in the 1772 00:36:38,829 --> 00:36:38,839 the engine in the 1773 00:36:38,839 --> 00:36:42,630 the engine in the cell fuel stored in wingtip tanks or in 1774 00:36:42,630 --> 00:36:42,640 cell fuel stored in wingtip tanks or in 1775 00:36:42,640 --> 00:36:45,750 cell fuel stored in wingtip tanks or in pods suspended below the wing represent 1776 00:36:45,750 --> 00:36:45,760 pods suspended below the wing represent 1777 00:36:45,760 --> 00:36:47,990 pods suspended below the wing represent current design trends 1778 00:36:47,990 --> 00:36:48,000 current design trends 1779 00:36:48,000 --> 00:36:50,230 current design trends which decrease the likelihood of contact 1780 00:36:50,230 --> 00:36:50,240 which decrease the likelihood of contact 1781 00:36:50,240 --> 00:36:51,670 which decrease the likelihood of contact between the fuel 1782 00:36:51,670 --> 00:36:51,680 between the fuel 1783 00:36:51,680 --> 00:36:54,790 between the fuel and the ignition sources devices or 1784 00:36:54,790 --> 00:36:54,800 and the ignition sources devices or 1785 00:36:54,800 --> 00:36:56,390 and the ignition sources devices or design features 1786 00:36:56,390 --> 00:36:56,400 design features 1787 00:36:56,400 --> 00:36:58,870 design features which act to intercept spilled fuel 1788 00:36:58,870 --> 00:36:58,880 which act to intercept spilled fuel 1789 00:36:58,880 --> 00:37:01,349 which act to intercept spilled fuel flowing within the airplane structure 1790 00:37:01,349 --> 00:37:01,359 flowing within the airplane structure 1791 00:37:01,359 --> 00:37:03,910 flowing within the airplane structure are also valuable 1792 00:37:03,910 --> 00:37:03,920 are also valuable 1793 00:37:03,920 --> 00:37:05,589 are also valuable provisions for the drainage of this 1794 00:37:05,589 --> 00:37:05,599 provisions for the drainage of this 1795 00:37:05,599 --> 00:37:07,589 provisions for the drainage of this intercepted fuel 1796 00:37:07,589 --> 00:37:07,599 intercepted fuel 1797 00:37:07,599 --> 00:37:10,069 intercepted fuel into the open air at spillage points 1798 00:37:10,069 --> 00:37:10,079 into the open air at spillage points 1799 00:37:10,079 --> 00:37:12,310 into the open air at spillage points away from the engine the cells 1800 00:37:12,310 --> 00:37:12,320 away from the engine the cells 1801 00:37:12,320 --> 00:37:14,150 away from the engine the cells would enhance the effectiveness of these 1802 00:37:14,150 --> 00:37:14,160 would enhance the effectiveness of these 1803 00:37:14,160 --> 00:37:16,150 would enhance the effectiveness of these arrangements 1804 00:37:16,150 --> 00:37:16,160 arrangements 1805 00:37:16,160 --> 00:37:18,470 arrangements location of landing lights away from 1806 00:37:18,470 --> 00:37:18,480 location of landing lights away from 1807 00:37:18,480 --> 00:37:20,230 location of landing lights away from cordwise positions 1808 00:37:20,230 --> 00:37:20,240 cordwise positions 1809 00:37:20,240 --> 00:37:22,310 cordwise positions in front of the fuel storage is 1810 00:37:22,310 --> 00:37:22,320 in front of the fuel storage is 1811 00:37:22,320 --> 00:37:24,310 in front of the fuel storage is indicated as well 1812 00:37:24,310 --> 00:37:24,320 indicated as well 1813 00:37:24,320 --> 00:37:26,390 indicated as well because these studies show how readily 1814 00:37:26,390 --> 00:37:26,400 because these studies show how readily 1815 00:37:26,400 --> 00:37:28,870 because these studies show how readily combustibles spilled in the cell are 1816 00:37:28,870 --> 00:37:28,880 combustibles spilled in the cell are 1817 00:37:28,880 --> 00:37:31,109 combustibles spilled in the cell are ignited it is desirable that the 1818 00:37:31,109 --> 00:37:31,119 ignited it is desirable that the 1819 00:37:31,119 --> 00:37:33,750 ignited it is desirable that the components of the fuel lubricating and 1820 00:37:33,750 --> 00:37:33,760 components of the fuel lubricating and 1821 00:37:33,760 --> 00:37:36,230 components of the fuel lubricating and hydraulic systems should be located high 1822 00:37:36,230 --> 00:37:36,240 hydraulic systems should be located high 1823 00:37:36,240 --> 00:37:38,550 hydraulic systems should be located high in the cell where crash damage to these 1824 00:37:38,550 --> 00:37:38,560 in the cell where crash damage to these 1825 00:37:38,560 --> 00:37:40,950 in the cell where crash damage to these compounds is least likely 1826 00:37:40,950 --> 00:37:40,960 compounds is least likely 1827 00:37:40,960 --> 00:37:43,349 compounds is least likely tubing containing combustibles should be 1828 00:37:43,349 --> 00:37:43,359 tubing containing combustibles should be 1829 00:37:43,359 --> 00:37:45,430 tubing containing combustibles should be designed to accommodate the cell 1830 00:37:45,430 --> 00:37:45,440 designed to accommodate the cell 1831 00:37:45,440 --> 00:37:47,670 designed to accommodate the cell distortions accompanying propeller and 1832 00:37:47,670 --> 00:37:47,680 distortions accompanying propeller and 1833 00:37:47,680 --> 00:37:49,510 distortions accompanying propeller and the cell impact 1834 00:37:49,510 --> 00:37:49,520 the cell impact 1835 00:37:49,520 --> 00:37:51,910 the cell impact preliminary data suggests the value of 1836 00:37:51,910 --> 00:37:51,920 preliminary data suggests the value of 1837 00:37:51,920 --> 00:37:54,150 preliminary data suggests the value of employing special paints which reduce 1838 00:37:54,150 --> 00:37:54,160 employing special paints which reduce 1839 00:37:54,160 --> 00:37:55,829 employing special paints which reduce the tendency toward the formation of 1840 00:37:55,829 --> 00:37:55,839 the tendency toward the formation of 1841 00:37:55,839 --> 00:37:58,150 the tendency toward the formation of electrostatic sparks on parts of the 1842 00:37:58,150 --> 00:37:58,160 electrostatic sparks on parts of the 1843 00:37:58,160 --> 00:38:00,069 electrostatic sparks on parts of the airplane likely to be detached in the 1844 00:38:00,069 --> 00:38:00,079 airplane likely to be detached in the 1845 00:38:00,079 --> 00:38:01,030 airplane likely to be detached in the crash 1846 00:38:01,030 --> 00:38:01,040 crash 1847 00:38:01,040 --> 00:38:03,670 crash and trail in the dust and fuel in the 1848 00:38:03,670 --> 00:38:03,680 and trail in the dust and fuel in the 1849 00:38:03,680 --> 00:38:06,150 and trail in the dust and fuel in the wake of the crashed airplane 1850 00:38:06,150 --> 00:38:06,160 wake of the crashed airplane 1851 00:38:06,160 --> 00:38:08,150 wake of the crashed airplane in an approach to an indicated price 1852 00:38:08,150 --> 00:38:08,160 in an approach to an indicated price 1853 00:38:08,160 --> 00:38:09,109 in an approach to an indicated price landing 1854 00:38:09,109 --> 00:38:09,119 landing 1855 00:38:09,119 --> 00:38:11,030 landing the pilot should de-energize all of the 1856 00:38:11,030 --> 00:38:11,040 the pilot should de-energize all of the 1857 00:38:11,040 --> 00:38:12,950 the pilot should de-energize all of the electrical system not required for the 1858 00:38:12,950 --> 00:38:12,960 electrical system not required for the 1859 00:38:12,960 --> 00:38:14,150 electrical system not required for the landing 1860 00:38:14,150 --> 00:38:14,160 landing 1861 00:38:14,160 --> 00:38:15,910 landing engine operation that provides the 1862 00:38:15,910 --> 00:38:15,920 engine operation that provides the 1863 00:38:15,920 --> 00:38:17,990 engine operation that provides the coolest exhaust disposal system should 1864 00:38:17,990 --> 00:38:18,000 coolest exhaust disposal system should 1865 00:38:18,000 --> 00:38:20,150 coolest exhaust disposal system should be practiced consistent with other 1866 00:38:20,150 --> 00:38:20,160 be practiced consistent with other 1867 00:38:20,160 --> 00:38:22,230 be practiced consistent with other safety considerations 1868 00:38:22,230 --> 00:38:22,240 safety considerations 1869 00:38:22,240 --> 00:38:24,310 safety considerations just before touchdown the fuel flow to 1870 00:38:24,310 --> 00:38:24,320 just before touchdown the fuel flow to 1871 00:38:24,320 --> 00:38:26,550 just before touchdown the fuel flow to the engine should be cut off to allow 1872 00:38:26,550 --> 00:38:26,560 the engine should be cut off to allow 1873 00:38:26,560 --> 00:38:29,349 the engine should be cut off to allow the engine to be purged with clean air 1874 00:38:29,349 --> 00:38:29,359 the engine to be purged with clean air 1875 00:38:29,359 --> 00:38:31,190 the engine to be purged with clean air in view of the effectiveness of the 1876 00:38:31,190 --> 00:38:31,200 in view of the effectiveness of the 1877 00:38:31,200 --> 00:38:33,109 in view of the effectiveness of the experimental ignition source alerting 1878 00:38:33,109 --> 00:38:33,119 experimental ignition source alerting 1879 00:38:33,119 --> 00:38:35,349 experimental ignition source alerting system in preventing crash fires 1880 00:38:35,349 --> 00:38:35,359 system in preventing crash fires 1881 00:38:35,359 --> 00:38:37,510 system in preventing crash fires experienced in this research 1882 00:38:37,510 --> 00:38:37,520 experienced in this research 1883 00:38:37,520 --> 00:38:39,510 experienced in this research further study of this system for special 1884 00:38:39,510 --> 00:38:39,520 further study of this system for special 1885 00:38:39,520 --> 00:38:42,630 further study of this system for special airplane application is desirable 1886 00:38:42,630 --> 00:38:42,640 airplane application is desirable 1887 00:38:42,640 --> 00:38:44,790 airplane application is desirable material covered in this motion picture 1888 00:38:44,790 --> 00:38:44,800 material covered in this motion picture 1889 00:38:44,800 --> 00:38:47,589 material covered in this motion picture has been published in an naca research 1890 00:38:47,589 --> 00:38:47,599 has been published in an naca research 1891 00:38:47,599 --> 00:38:50,630 has been published in an naca research memorandum entitled mechanism of start 1892 00:38:50,630 --> 00:38:50,640 memorandum entitled mechanism of start 1893 00:38:50,640 --> 00:38:55,720 memorandum entitled mechanism of start and development of aircraft crash fires