Originally Posted by
undflyboy06
I believe that Vyse acts exactly the same as Vy as you increase altitude....decreases. There will be times when you fly that certain atmospheric conditions will the aircraft to perform better at speeds a little below Vyse, and when I say a little I mean only a few knots. Hopefully I'm right, and hoping that someone will correct me if I'm wrong.
Also, I'm not sure if you were referring to gaining 100 fpm to absolute ceiling. Absolute ceiling is where you cannot gain anymore altitude at Vy because the slightest change in pitch, roll or power reduction will cause you to loose altitude.
You are right. Vyse does act the same as Vy, and decreases with altitude. VMC, however also decreases with an increase in altitude. This is because all of the factors from the operating engine (torque, pfactor, slipstream, etc.) are decreased because propeller efficiency is diminished with a decrease in the concentration of air molecules as you fly higher.
Just think about it - air is more dense at lower altitudes, therefore the propeller takes bigger bites out of the air, being more effective. This in turn makes all of those factors greater in intensity.
Hope this helps a little - I miss teaching this stuff!!