Re: Virgin Atlantic GlobalFlyer


<onehappymadman@xxxxxxxxx> wrote in message
news:1139592223.859012.209380@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
This is interesting.

http://www.virginatlanticglobalflyer.com/Aircraft/Introduction/index.jsp

"Aerodynamics are key to this aircraft, and its configuration is
optimised for range and fuel efficiency. The aircraft's aerodynamics
have been designed using extremely sophisticated computing technology
that uses computational fluid dynamics to predict how the aircraft's
surfaces will behave in flight. The aircraft is so aerodynamically
perfect, that the only practical way to descend is using drag
parachutes, like the ones in the picture above..."

While I was intrigued that CFD could create an aircraft that is nearly
"aerodynamically perfect", I fail to understand why parachutes are
necessary. Can't the pilot descend simply by throttling down /
deactivating his engine? Sure, descent might take a little longer than
for a Boeing 737, but come on, he's not flying in a vacuum...

You've never flown a glider, I take it. Probably never flown at all
except as a passenger. Try filling the bathtub with water (or use the
swimming pool if you have one) and see what various shapes "land" like.
You can try a frisbee, a knitting needle (plastic), a steel rod, a dinner
plate,
a *** of thin card, anything you like, but remember that a "crash"
is anything that isn't a perfect touchdown in the dead centre of the
tub or pool. Updrafts, crosswinds, all have to be considered, but
in real life landing just 10 feet to the side of the runway in the grass
is a "crash" that can cause death when a wingtip digs in.
Drag chutes are used on cars and by the shuttle. They are inexpensive,
cheaper than air brakes that require hydraulics and although they require
repacking, the plane isn't rushing to the gate to discharge its passengers,
reload and fly again with a rapid turnaround.
Androcles.




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