Fixed Derates are done by the OEM usually to leave room for further expansion and development on an engine/airframe platform...Pilot selected Derates are what, that word usually implies in non-engineering parlance
btw what's wrong with HTBJ--all you really need to know...I think at times all ATP topic get a little 'creative with aerodynamics, and actually end up missing the important facts....If an interviewer wants to hear crap spouted from that book at him---then read, the book and to get the stinking job, as times are lean and everything is a hustle
... thereafter, use the leaves therefrom, for paper airplane construction, as, you'll learn far more aerodynamic theory in that way
