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HAWK21M
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Joined: Fri Jan 05, 2001 10:05 pm

Pressurization Check.

Mon Aug 13, 2001 4:48 pm

The pressurization check on Grd of a B737, consists of shutting off the packs post pressurization & watching for the drop in cabin pressure & at what rate.

How much damage can the Eardrums withstand if the Main Outflow valve is opened rapidly & secondly what is the maximum rate of cabin pressure change that can be withstood.

regds
HAWK.
I may not win often, but I damn well never lose!!! ;)
 
air2gxs
Posts: 1443
Joined: Mon Jun 18, 2001 1:29 pm

RE: Pressurization Check.

Mon Aug 13, 2001 5:07 pm

I've been on several aircraft where we dumped the pressure rapidly. I've never sustained any injury, nor did any of those with me. There is a little discomfort but nothing major. The maximom rate is over 2000 fpm (that's the peg on the last airplane I was involved with).

I wouldn't want to do it if I was having problems with my sinuses though. OUCH!.

I would say that its an individual issue.

I will say that I have caused it to fog up pretty good on a jumbo. The outside conditions need to be hot & humid (not unheard of here or at JFK) and you need to dump the pressure pretty quick from about 6 or 7 psid.
 
Twotterwrench
Posts: 1087
Joined: Tue Jan 16, 2001 5:57 pm

RE: Pressurization Check.

Mon Aug 13, 2001 6:14 pm

It is cool as hell to pop the safety valve and let her go! Doesn't bother my ears at all, but the temp drops about 20 degrees instantly and the cabin fills with fog. Pretty cool... I love to do it when a new guy is in the right seat with me...scares the shitties out of em....
 
NKP S2
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Joined: Mon Dec 20, 1999 3:16 am

RE: Pressurization Check.

Mon Aug 13, 2001 6:29 pm

It may well vary with different models of 737s, but IIRC ( and the revised MM should be the ultimate authority ) you measure the hull leakdown rate from 6 to 4 PSID. I believe it should be around 2-2.5 minutes ( but I'm not positive ). Even though I have more sensitive ears than most ( my achilles heel ), and the resulting cabin climb pegs the indicator at 4000'/min, the discomfort is not unduly harsh.
 
Notar520AC
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Joined: Sat Jul 21, 2001 6:53 am

RE: Pressurization Check.

Wed Aug 15, 2001 9:53 am

Just had to share this- Once a pilot didn't disengage the pressureization upon arrival and the FA opened the galley service door and flew out of the aircraft about 50 feet! They should offer that ride in the amusment parks!
BMW - The Ultimate Driving Machine
 
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HAWK21M
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Posts: 29867
Joined: Fri Jan 05, 2001 10:05 pm

RE: Pressurization Check.

Wed Aug 15, 2001 4:24 pm

Thats where Aircrafts with Plug type door work to an advantage rather than sliding type.
In case the Aircraft is pressurized depending on the amount of Differential pressure,it would be impossible to override the door open.
regds
HAWK.
I may not win often, but I damn well never lose!!! ;)

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