Cheers,
I just wanted to send an example of coffin corner, which might make
the topic clearer:
The deHav 100 Vampire Mk.III had a critical Mach number of 0.78M (without
drop tanks) - not bad for a wooden aircraft with 3000 Lb thrust -
It stalls (half empty) at about 95 knots indicated.
Depending on the temp, that speed is about 220 knots true at 48000 feet.
Also depending on temp, that's pretty close to 0.78M.
Go a bit slower, stall clean.
Go a bit faster, tuck under and see earth straight down.
To escape the 'corner', drop the speed brakes - basically an 'indicated'
function - descend at 100 knots to thicker air.
We were told not to do this too often as pressure breathing is needed above
about 35,000 and some of that the Vampire didn't have any of.
I am told some models of the Venom were powerful enough to go much higher
but then couldn't get back down because thye were in too thin air and could
run out of O2 before they brakes took effect - solution - spin down to
thicker air. Trouble was, if there was a traumatic temp change at the
tropopause, a wing came off. Don't know if this was so........
Ferg
A064 mono 914 CS prop
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