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TeddyRuxpin
13th Jun 2009, 11:00
Is Coffin Corner something that anyone's experienced? Is it always catestrophic or redeemable? If so, how much skill is required to right the situation in a standard passenger plane?


I heard that the Lockheed operates in Q quite a bit - how is this so :confused:

SNS3Guppy
13th Jun 2009, 15:58
Most passenger and corporate aircraft dont' have the performance capability to fly to coffin corner, and always have a reasonably wide margin between mach buffet and aerodynamic stall. Even at the highest operating altitude.

"Coffin Corner" seems to be a buzzword just lately. Everyone is concerned about it, all of a sudden. There's nothing to be concerned about, because it's not an issue unless you're in a U2.

emeritus
14th Jun 2009, 12:43
Not sure about modern generation of jet aircraft but "coffin corner " was certainly something to be concerned about.

The Boeing 727 was capable of operating in this area when above F370 as I once found out when at a reasonably low AUW.

At 1g it may be reasonably high but run into turbulence and have the wing loading go up to 1.5/2.0/2.5g and coffin corner can come down to meet you. Feels like you are sitting on top of a flagpole and with max cruise EPR there is no extra thrust for acceleration.

I mostly selected an alt that gave a minimum of 20 kts between low/high speed buffet.

There is a good explanation of this area in "Handling the big jets" by D.P. Davies, pages 165 to 170

Emeritus