Originally Posted by John Farley
To a pilot today Angle of Attack is the angle between the chord line of an aerofoil and the direction of the local airflow as it approaches the aerofoil.
Partial quote from BEA's Final Report on the A320 accident near Perpignan, para. 1.6.6.1:
The aeroplane angle of attack (also called true, real or corrected angle of
attack) is defined by the angle between the relative wind infinitely upstream
and the longitudinal axis of the aeroplane. It is generally noted as α (alpha).
regards,
HN39