writes:

Barry Schiff recently wrote an article about how he was being checked
out for a rental and he set his speed to 55kts during the engine-out
exercise because that is the "rate of least descent" for an airplane
with a best glide speed of 67 knots. He was trying to set the "least
descent" speed to give him time to choose an adequate landing site at
which time he would have set the nose for the best glide speed. While
Mr. Schiff was right, he got gigged on it and found himself having to
prove himself and educate an instructor instead of getting the sign-off
and an airplane for an afternoon.

He'd have been much better off, for his own purposes, to have been
selfish, done as the instructor expected and then rent the airplane. I
suspect you might want to think the same way since you're not in a
position of credibility as a student and this particular piece of
knowledge is probably not universally taught to instructors of powered
aircraft. I'm also betting you are correct and that the rules of
physics do not change just because you add 300 lbs of dead weight and a
motionless propeller to the front of the glider. But, what is it you're
trying to do? Prove something he doesn't know? Or are you more
interested in proving your competence by his standards?

In other words, for what you're trying to get done, please the
professor first. Engage in the debate after you get your license. Odds
are that you'd have the same tough sell in front of you if you attempt
the same argument during your checkride. You can prove you're right
later.

Does that seem sensible?

No, because the same instructor may misinform others who do not have
the benefit of other sources of information, and someone may be
injured or killed as a result of his misinformation.

Correct the instructor if he is wrong. If this creates an obstacle to
attaining your own objectives, find another instructor. But don't
just leave him to put other students in danger.

--
Transpose mxsmanic and gmail to reach me by e-mail.