Ram Rise

[3RAR]

Dose anyone have a simple rule of thumb to account for ramrise through FL110 and higher? Especially if you know of one that works well around freezing level when flying with an indicated OAT only.

3

[pig dog]

On the 737 at typical flight levels and airspeeds, 10kt IAS is equivalent to 1 deg C RAM rise +/- a degree or two. i.e. if TAT= -19 & IAS= 260kt, OAT is approx -45 deg. Not sure if this rule of thumb applicable to typical turboprop speeds and altitudes, but should work well in most jets.