Originally Posted by
Pugilistic Animus
.which version of HTBJ are you referring to? I can't find it
3rd edition Dec 71 page 170 refers to the use of flaps at high altitude. DPD refers to pilots who have developed a habit of using flaps at altitude which has raised concerns. His primary concern is that flap design is based on their use for TO, climb, decent and landing and will be retracted for the rest of the flight. The strength and fatigue calculations for the flaps are based on this normal use. He goes on to point out that the flight manual limitations for flap use are there for reasons and should be observed.