Well you may well be right, I did very clearly state that I am no expert it has been a while since i studied this subject although I did get 93% in the exam at the time, having done some proper hunting via google i can find several sources that actually say thrust required decreases as altitude increases how acurate this is i don't know but I think I will do some looking up and try and enhance my understanding of these principles, thats the beauty of aviation you learn something new every day.........