How indicative of agility are max G numbers?

"WaltBJ" wrote in message
om...
There's a mix here involved. Max G available, G onset (how fast can
you load it up) and corner velocity - the minimum speed do you need to
generate the lift necessary attain max G. A lot of limitations pop up
now. Higher the G, teh stronger tha irplane must be, and therefore the
weight goes up, so the wing has to be bigger. Also to sustain the G
you need more thrust because induced drag (drag due to generating
lift) goes sky-high.
Generally the design working G limit has been either 7 1/2 or 9 - and
with a 50% safety factor that means the structural yield limit ( bent
and won't 'unbend' either 11 1/4 or 13.5 G. Human G tolerance depends
a great deal on training fitness and 'want to'. I have seen 10.5 on a
G-meter whena student 'dug in' an F4 decelerating through the Mach -
my forward push stopped it from going even higher. My G tolerance came
from flying the F102 sans G-suit and hasseling with anything that came
along. It could pull 3G at 200 KIAS, 7G at about 325, though not for
long (delta wing at airspeed!) FWIW I have a friend who was conscious
and talking to the doctors on USC's centrifuge at 11 G sustained. He
is about 6-2 and 180. Also, I know of two incidents were the pilots
recovered their aircraft pulling 12 (F106) and 13 G (F86D)
respectively after getting the nose buried close to the ground. Yes,
the aircraft were severely bent, but the pilots survived. Adrenalin is
a wonder drug in these cases - special cases of 'want to'.
Walt BJ

Yeah, it's a multiples thing all right, especially if you throw corner in
there . Below corner you're aerodynamically limited and above you're
structurally limited; go high enough and you're thrust limited as well......
but just considering g alone which was his question, and forgetting rate and
radius, you can pull max g all the way out to the right side of the envelope
until either you or the airplane starts complaining :-)
But I agree with you. You can't even begin to discuss fighter performance
using a one aspect only condition. There's just too much involved, and the
whole thing has to be integrated into the discussion for anything to make
sense at all.
Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/ CFI Retired
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