Interesting door dilemma

[Midnight Music 252]

I am currently touring South America with my wonderful NGX 737. However, I encountered an odd problem when I landed at La Paz, Bolivia, which is at 13,300 feet. The FMC would not let me open the doors as I usually do upon parking for the AES services. Any suggestions? Is there a setting somewhere I missed? I have been looking through the manuals but have not come across a solution yet. If anyone has a suggestion I'd be very appreciative.

 

Lee

[killkenny1 22]

I think it has something to do with pressurization.

Let's wait till someone with more knowledge chips in.

[rsvit 16]

Try doing supplementary procedures for high-field airport landing.

If it doesn't work, switch to manual pressurization control and hold the outflow valve switch in OPEN position until it's fully opened. Wait until diff pressure became zero.

[hopskip 253]

Yep. You can't open the doors when you are airborne because the air pressure inside the cabin higher (lower relitave altitude) than the outside air. Typically the air pressure in the cabin is between the equivalent of 6000 and 8000ft altitude depending on actual cruise height.

 

at 13,300ft actual altitude, the 6000ft pressurized air inside the cabin is literally holding the door shut. You need to equalize the pressure. (as above) before opening the doors... erm, before opening the doors is physically possible.

[Midnight Music 252]

Got it, I see where the manual switch is. I thought that by entering the airport altitude it would do it automatically, but I guess not.

 

Lee

[EdubFlyer 2]

you're not allowed to land pressurized either there is a special procedure. Also there is a high altitude option from boeing me thinks

[Captain Kevin 586]

I am currently touring South America with my wonderful NGX 737. However, I encountered an odd problem when I landed at La Paz, Bolivia, which is at 13,300 feet. The FMC would not let me open the doors as I usually do upon parking for the AES services. Any suggestions?

Perhaps it is trying to tell you something about your destination.

 

Sorry, couldn't resist.

[captainoleary 0]

Do you even have to manually adjust pressure, or will auto work if the landing altitude dial is set correctly?

[tcas_climb 45]

nvm

[Airbusman330 300]

Did you set the proper landing altitude in the pressurization panel?

[Midnight Music 252]

I did set the landing altitude, I always do. Curious why it didn't react.

 

Lee

[Airbusman330 300]

I don't know then, what is the highest altitude the 737 is certified to land at?

[Chrjs 61]

I don't know then, what is the highest altitude the 737 is certified to land at?

I think it is 8,400ft - but there is an airliner-option to raise it to 12,000/14,500ft, though not included int the NGX.

[EdubFlyer 2]

Also you need to set your landing altitude to 6000 until 20 minutes before landing, then raise it to landing altitude

[Midnight Music 252]

I don't think that is correct. I finally found this passage in the Tutorial # 2 Manual

 

• Verify that the AUTO FAIL and OFF SCHED DESCENT lights

are both extinguished.

• Set the FLT ALT to our planned cruise altitude – 39000.

• Set the LAND ALT to the destination elevation rounded up to

the nearest 50 feet. Innsbruck Runway 8 is 1906 feet, so we’ll

set this to 1950.

 

The answer might be that the altitude has to be rounded "up" to the nearest altitude. I am wondering if I inadvertently rounded it "down". I will check that next time I go into that scenery.

 

Lee