SPIT MK I/II and over boost

[Crumpp]

There is no reason for a huge involved, "Gee Whiz, I wish I was smart" discussion on this topic.

It is a simple fact, an airplanes climb speeds or Vx and Vy, are not constant with altitude. No amount of tap dancing or splitting hairs will change the physics.

In practical terms for flying an airplane it is easier to remember a few speeds for Vx and Vy that get you in the ballpark or just hold it constant so you only have to remember 2 numbers.