[Political Junkie Too]

I recall reading stories (perhaps a myth) that pilots were not running the air conditioners in order to save fuel.

I just did a short Google search, and found some articles on older Boeing 747s where this was possible.

-PJ

[ThomasThomas]

The outside temperatures are really low, all you need to do is have one window open just a crack and it will cool the whole plane.

[CFIIIMEIATP737]

I have not flown the 747. I am typed in the 737 but most recently I have been flying corporate jets. Some of those jets have an electrically driven air conditioner. When it activates, you can definitely see an increase in amperage, so I assume there would be a slight increase in fuel flow, but it doesn’t show on the fuel flow gauges. The other corporate jets I fly have what is called an air cycle machine. We shut the air conditioner portion of it off at 18,000 feet. At that point we are trying to heat the air for creature comfort, not cool it. Temperatures in the upper flight levels are easily minus thirty to minus fifty centigrade.