Thanks JF. I just dragged out AP3456 (which I'm sure you could almost quote verbatim
) and found this in CHAPTER 2 - AERODYNAMIC FORCE, Symbols and Definitions,
i. Angle of Attack ( a ). The angle between the chord line and the flight path or RAF. In many textbooks this is referred to as Incidence.
j. (Rigger’s) Angle of Incidence. The angle at which an aerofoil is attached to the fuselage. The angle between the mean chord line and the longitudinal fuselage datum. The term is often used erroneously instead of Angle of Attack.
Further
a. Free Stream Flow. Air in a region where pressure, temperature and relative velocity are unaffected by the passage of the aircraft through it. Sometimes called relative airflow (RAF).
Not a day you don't learn something new. Hence, Davies was quite correct in his usage IMHO.