P-ceiling vs. T-ceiling

[jchronic]

As someone whose normal Skymaster flying never takes them much above 1000 feet, this discussion is somewhat academic to me. But thought I'd throw out something for you high-flyers to keep in the back of your mind: getting down from up there in the event of an emergency.

Short sea story from my airline days: Had a rapid decompression in a DC9 at FL350 and as we configured the airplane for a rapid descent, it began a violent buffeting. Natural assumption was some kind of structural failure/damage so we elected to descend at 230-240 KIAS instead of M.8/350KIAS. It was about the longest 15 minutes of my career, thinking the airplane might be coming unglued.

Certainly not a reason not to fly high if the mission calls for it, but remember that it will take some time to get down from up there.

Joe

[Red Air Rambo]

Originally Posted by jchronic

As someone whose normal Skymaster flying never takes them much above 1000 feet, this discussion is somewhat academic to me. But thought I'd throw out something for you high-flyers to keep in the back of your mind: getting down from up there in the event of an emergency.

Short sea story from my airline days: Had a rapid decompression in a DC9 at FL350 and as we configured the airplane for a rapid descent, it began a violent buffeting. Natural assumption was some kind of structural failure/damage so we elected to descend at 230-240 KIAS instead of M.8/350KIAS. It was about the longest 15 minutes of my career, thinking the airplane might be coming unglued.

Certainly not a reason not to fly high if the mission calls for it, but remember that it will take some time to get down from up there.

Joe

+1 , however from my 7 trips to the altitude chamber during 22 years of military service I can tell you that time of useful consciousness at 35,000-37,000 is around 5 minutes at best. 18,0000-20,0000 is 30+ for most (we never spent more than 30 minutes at 18,000 before climbling up and no one went out). With the warning systems on the aircraft, gear down and spoiler's out (if so equipped) you can acheive 2000 fpm and be below 12,500 in 3-5 minutes. If you need more time use mask's.....at least for the pilot, if oxygen equipped (and u should be if venturing into the flight levels). Having been part of the squadron that intercepted Payne Stewart's plane I know about altitude's effect all too well. That said I love the tail winds in winter when flying east and I like the weather below me!

[wybenga]

The P is not certified above 20,000 because it does not have an emergency exit and it operated on a waiver for supplemental oxygen which was not standard on the airplane as certified