Re: Helicopters and courtyards

On May 6, 11:46�pm, Gosh Darn <kefisc...@iglou.com> wrote:

� � � � �I thought it was well known that a helicopter cannot hover
or land in a courtyard, the walls cause the airflow to form a
doughnut shaped torus of air, instead of being accellerated
downward and outward.

� � � � �This made the news 20 or 30 years a go when a woman
pilot was asked to hover in a church or school courtyard while
a man tossed out prizes of some sort. � �
� � � � �People were decapitated when the hekicopter lost
lift and fell.

� � � � �As far as low radar cross section helicopters go, the
patent office included a 1977 study on the uh-60 in the
office response to the application I mailed on Dec. 22, 1978.
� � � � �It was stamped "Level 12", whatever that meant,
I had no clearance at any time, and that application was
never under secrecy order.


This is the dreaded vortex ring. However they hover in choppers all
the time, so I don't know why it is considered appropriate in some
situations. Pilots given their druthers rather fly tight orbits than
hover to avoid the vortex ring.

I was in a traffic helicopter that was doing tight orbits over a crash
scene. I had a GPS with me and the horizontal velocity was about
60mph. I think the pilot was trying to make me hurl.

I think you make a helicopter stealthy by flying it in the radar holes
as much as possible. ACE has software to predict the dead spots.
Of course there are civilian programs that can do the same thing, such
as the open source version of GRASS, SPAT!, and radio mobile.