@Dutch M
1. Usage of TAS to calculate Kinetic Energie exchange for height.
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I politely suggest you go a read the Wikipedia article on Kinetic Energy. It is correct to use the airmass as reference and airspeed to calculate the KE relative to the axes (its not an absolute quantity). Newton's 2nd law is all about momentum, and momentum is linear in velocity (for constant mass). The equation for Kinetic Energy comes from integrating the momentum from one velocity to another. You do not have to take in account the KE of the system relative to the earth, sun, milkway etc - just use the same axes set before and after. So IMHO it is correct to just use 1/2m(v2^2 - v1^2) = mgh, you do not need intertial equivalents for v. 1/2m(v1-v2)^2 is wrong - unless v1 or v2 are zero!