1
$\begingroup$

I am interested in knowing the theoretical and practical differences between the Angle of Attack (AoA) and Pitch:

  • Graphical definitions
  • How are they related?
  • In what circumstances these angles are equal?
  • While flying, do you need to consider both or only the Pitch?

Thanks in advance :)

$\endgroup$
2
$\begingroup$

Angle of attack is the angle between the relative wind and the chord of the wing. Pitch is the angle between the longitudinal axis of the aircraft and the horizon.

They are related, (and both are controlled with the elevator) but independent of each other. In high speed straight and level flight they are probably the closest to being equal, but generally there will be some positive angle of attack needed to maintain lift. This is due to angle of incidence; the designed-in angle between the longitudinal axis and the wing chord.

Pitch and AoA can be vastly different though. Consider a loop: The pitch will change 360 degrees while the AoA may stay exactly the same.

A pilot needs to consider both. Decelerating in straight and level flight will require gradually increasing AoA to maintain lift. (which will also increase pitch...) At some point you will reach the critical AoA where airflow separation leads to a stall.

This can also happen in a climb or descent, and at varying pitch angles. I will stop there and not go more into stalls or accelerated stalls because it is beyond the scope of your question, but I wanted to at least touch on it because if you understand that then the relationship between pitch and AoA will become more clear.

| improve this answer | |
$\endgroup$
7
$\begingroup$

The reference of pitch is the horizontal. The reference of AoA is the direction of the relative wind.

| improve this answer | |
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.