Geez...I can't win

Vince · Posted: Sun Feb 14, 2016 3:51 am Post subject: Geez...I can't win

I've come to the conclusion I couldn't win a king hit in a pub brawl. A bloke tries to do the right thing and...

dhc4ever · Posted: Sun Feb 14, 2016 4:37 am Post subject: Re: Geez...I can't win

They wont open in flight Vince.
At 41000 ft the cabin pressure is equivalent to 8000 ft.
This gives a differential pressure of 8.35 psi.
A cabin door is someting like 80 inches x 36 inches which equals 2880 square inches multplied by 8.35 equals roughly 24,000 lbs keeping that door closed.
Dont you love physics.

slimjim · Posted: Sun Feb 14, 2016 7:56 am Post subject: Re: Geez...I can't win

dhc4ever wrote:

Dont you love physics.

Right on Pete!

Vince · Posted: Sun Feb 14, 2016 8:09 am Post subject: Re: Geez...I can't win

dhc4ever wrote:

They wont open in flight Vince.
At 41000 ft the cabin pressure is equivalent to 8000 ft.
This gives a differential pressure of 8.35 psi.
A cabin door is someting like 80 inches x 36 inches which equals 2880 square inches multplied by 8.35 equals roughly 24,000 lbs keeping that door closed.
Dont you love physics.

Maybe they had just tn off or were about to land...I dunno mate. Or maybe he was the Hulk in disguise and 24K lbs means nuffin to him. Haha

dhc4ever · Posted: Mon Feb 15, 2016 2:39 am Post subject: Re: Geez...I can't win

Surprisingly it doesnt take a lot of pressure for the door to be forced shut.
We used to lock the Radio techs out of the P3 Orion's by pressurizing the cabin to 1 inch of mercury. 30.2 inches of mercury approx = 1 atmosphere.
They were not amused especially when the temp outside was 40C+.
Ah the good old days when my knowledge and abilities were appreciated.

PaulS · Posted: Tue Feb 16, 2016 12:46 am Post subject: Re: Geez...I can't win

There is a bleed off valve on the door - but yes the pressure would have to equalize first and that bleed off won't drain enough air that the compressor won't keep up with it.