[Capt. Tom]

It’s AOA to the apparent wind. Not angle of aircraft to the earth.

I would think that would be useless when you are traveling so fast. The wind wold be parallel to the direction the plane is moving.
IMHO The angle to the earth would be a better indicator of the flight path. - Tom.

[TexasGator]

Best you not comment on this subject till you do some homework.