Hello there!
I have a quick question which is relavent to this thread. I am aware that the tropopause is reached at around 36,500ft, and that the temperature of the air at this altitude should, according to the ISA formulae used above be -57 degrees-ish, and according to my reference material, the temperature stays roughly the same from there on up. Is this the part of the ISA definition? And if not, for standard calcs and performance graphs etc
should this plateau be taken into account?