environmental envelope

[richard III]

Hi all:
would like to have an input on the "A" that appears in the assumed temperature column in the AA charts, when the aircraft is too light. is this a restriction. Nobody seems to care much about it since performance falls seldom in this area. But "outside environmental envelope" looks like a restriction to me.
Thanks for the help

[mutt]

It means you can assume the performance to that temperature, but if you happen to be somewhere and the real altitude temperature is outside the envelope, then you cannot operate.

Mutt

[richard III]

tks mutt, much appreciated, just one doubt, you start on the assumed temp column, and scroll down until you find your actual tow and you assume that temperature for the take off, meaning that you would not actually consider the take off at temperatures at above 56 degrees. Not quite clear, would you mind elaborating?. Thanks for the help

[FE Hoppy]

That's quite some doubt!

[mutt]

Easier way is to take the airport ISA temperature, 15C at sea level, add 39.4 degrees to it, (39.4 degrees Boeing)(39 degrees Embraer and Airbus)(35 degrees Bombardier), the resulting temperature is the maximum actual temperature that you can takeoff/land.

As for the chart, start on the bottom, lightest weight @ highest temperature, moving up you can see the weight decrease as the temperature decreases. This might make it easier for you to visualize.

Mutt

[richard III]

tks mutt, got it, I do appreciate your time and patience.
cheers