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Thread: Coffin Corner
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Old 23rd Jun 2008, 18:32
  #28 (permalink)  
Lemurian

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I can't imagine an airline driver getting anywhere near it in normal ops.
It has happened a few times in the pre-FMC era : an underestimation of weight would be enough to be too high . A jet upset is another example when the airplane is submitted to a g-factor higher than planned...
An incident where the influence of flying too close to the max aerodynamic ceiling had a part was the China Air 747 : High altitude, high AoA and an engine flame out....made interesting aerobatics.
This is a forum, not a cockpit.
...and it should reflect what we experience in our lives in the cockpit.
That term that you readily coined as CC has absolutely no official existence in our manuals, but we use terms like :
"Buffet Ceiling"
,. "Buffet Onset", "Buffet Limited Altitudes", "En-Route Maneuver limits"...etc...CC is just club bar crap (but it came from real-life experience of those gallant test pilots of the fifties who went up there to find out ) and its official name is "LIFT CEILING"
Coffin Corner "sounds hard to reach". Only if you can't imagine flying well past it.
You can't fly past it unless you tried to zoom it from a lower altitude, but you'd be stalling anyway...
This discussion is a perfect demonstration on how imprecise, unofficial undefined concepts can spoil a technological approach to a problem : is a corner a zone or a dot ?
If it's a zone, refer to the buffet margins graph of your airplane
If it's the summit of your curve - i.e a dot -, you are talking of a situation that is best described as accidental severe upset....see your training manual or get the Boeing or Airbus texts on upset recovery.
But you are at Vne, so the Stall becomes disastrous. Likewise, if you alter Pitch up or down you tumble out of control.
And now you start your usual uninformed blurb : You are NOWHERE NEAR Vne, as the parameter that causes the phenomenon is not Mach number, M, but the Clmax . Mē part of the lift equation....Therefore, your explanation is in error...

Last edited by Lemurian; 23rd Jun 2008 at 18:43. Reason: New post while editing
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