I've noticed that on landing approach I get a warning light message on the glareshield annunciator panel for "air conditioning". I'm stumped as to what this is telling me and how to correct it, if needed. This occurs on the 737-900. I haven't looked for it on other models, e.g. 600, 700, 800. Any help would be appreciated.Thanks,Jim

Have you set the correct landing altitude on the overhead panel?

That is a possible explanation, although the landing altitude is 94' and I may have the setting on 0'. I'll be sure to check it out and let you know.Thanks for the reminder.Jim

Only a guess...not too familiar with the NG just yet!

Here is my experience: that message is commonly triggered when you start an "too early" descent. That is, when you start your descent before having reached your selected cruise altitude in the pressurization panel (overhead).So, if for any reason you start descending before reaching cruise altitude: then, first, re-select a lower new crz alt in the overhead press panel, and also in your FMC.Check also the cabin temp indicators (overhead). The message can aso be triggered by a very low or very high cabin temp (that should discomfort your passengers). If that is the problem, rotate both temp knobs to the left side (cool) or to the right (warm).I hope this can help you.Jose Luis

Thanks Jose Luis.I was cruising at 4000' and I've never seen this before on the 700 model. I am doing the flight lessons in Tim Metzinger's tutorial ver. 2. This was on a flight from KTNT to KMCO. Other flights were at 2500'. In niether case did I set the pressure temp on the OVHD and as I mentioned, only saw the warning appear on the KTNT to KMCO flight using the 900 model.I'll check out your suggestion on the next flight I make.Jim

Hum, hum !! There is nothing called "pressure temp", I am talking about two different overhead-panel sections:1.- The pressurization panel, where you must select a cruise altitude and a landing altitude.2.- The air conditioning panel, which has two big rotating knobs to lower or rise the cabin air temperature.This is well explained in the 737 manuals.Jose Luis.

Bad use of terminology on my part. I was aware of what you were describing and I'll check everything out on the next flight.Jim