"air cond" in NG 737

[Guest stayup]

When descending from a low level crz alt(8000ft msl) flying from PHNL to PHOG the "air cond" warning goes on in the caution and warning panel.Also, occasionally , occurs on other flights with high crz altitudes. As far as I can see, the pneumatic system is properly set up....the L and R packs are set on auto, the recirculation switch is on auto , and both bleed air switches are on. Does anyone have any idea why this happens?Thanks,Irv Strongin

[John_Tavendale 453]

Try setting the cruise altitude on the overhead panel, I am fairly sure it's the cause of this. :)

[Guest stayup]

Hi John,Thanks for the response...it worked, but I don't understand why you would have to activate the pressurization system on a flight under 10000 feet. Maybe its a bug.Best regards,Irv Strongin

[Guest tmetzinger]

>Hi John,>Thanks for the response...it worked, but I don't understand>why you would have to activate the pressurization system on a>flight under 10000 feet. Maybe its a bug.>Best regards,>Irv StronginNope, normal practice... Pressurization maintains a sea level cabin while it can, and only when the pressure differential is too great does the cabin start to climb.Passengers will be more comfortable with pressurization, even on a short flight at "low" altitudes.

[Guest stayup]

Hi Tim,Thanks for the response.Best regards,Irv Strongin

[Guest JoeInCT]

This was my first question with the 737 when I first started flying the 737NG!!!. When I did a search on the forum and found a few posts regarding the Air Cond light, I was even more confused -- at least initially. What does the Air Condition have to do with setting the cruise altitude? Thought I had to keep looking for the answer on the boards -- but nope, the cruise alt is the answer. Instead of displaying a message that makes sense -- like Cabin Alt Config or something like that -- Boeing chose to display a "Air Cond" indication if you don't set your cruise altitude before takeoff. I thought the whole point of newer automation was to hide unimportant info, and display qualitative info to the pilots. Doesn't seem like this is the case here. I don't get it.

[Guest JoeInCT]

Oooops. Forgot to sign my name. Wife was standing over me waiting to go to dinner. Sorry.JoeInCT (Joseph Szarmach)