[HOW-TO] F/A-18E Landing Guide

[CaptainRude91]

@jssamp

First, because of the curvature of the Earth, at high flight levels the visual horizon falls below your horizontal reference plane.

Not relevant at all for the determination of pitch angle.

@jssamp

Second, longitudinal axis is the roll axis and is very often closely aligned with the nose and tail

The very definition of PITCH = the angle between the longitudinal axis and the horizon. The chord line changes when extending leading edge or trailing edge devices so its not even a fixed reference.

@jssamp

But to give an extreme example, the F-8 Crusader had a variable angle of attack wing to allow for high speed flight and increased the AOA for more lift on landing and take off.

That is exactly why the chord line is not used as a reference for pitch.

As for chord line: