To fly a given IAS, the thrust required at altitude??

[Merritt]

several sources that actually say thrust required decreases as altitude increases

Im only a lowly ppl'er but my understanding is that this is correct if you maintain a constant TRUE air speed. If you maintain a constant IAS, you are actually increasing your TAS.

From the engines point of view, it looses thrust as altitute increases (all other things being equal) because the air is less dense. In order to maintain the same thrust, the throttle needs to be advanced.


Steve