This answer to a related question stated:
Most anything can have an angle of attack. If you must be specific, you mention 'angle of attack of ...'
...
When we talk about airplane as a whole, usually the 'default' angle of attack is the one between the wind and the body frame (in the vertical plane). How body frame is defined depends on the aircraft designer, but normally X goes along the fuselage. Therefore, the angle of attack is exactly what you say: the angle between relative wind and the fuselage -- and not that of the wing (even though it is arguably more important).
While this answer to another related question stated:
From A.C. Kermode; Mechanics of Flight, London, Pitman, 8th Edn, 1972, p.75 (his bold):
"We call the angle between the chord of the aerofoil and the direction of the airflow the angle of attack.
"This angle is often known as the angle of incidence; the term was avoided in early editions of this book because it was apt to be confused with the riggers' angle of incidence, i.e. the angle between the chord of the aerofoil and some fixed datum line in the aeroplane. Now that aircraft are no longer "rigged" (in the old sense) there is no objection to the term angle of incidence; but by the same token there is no objection either to angle of attack, many pilots and others have become accustomed to it; it is almost universally used in America, and so we shall continue to use it in this edition."
And from L.J. Clancy; Aerodynamics, London, Pitman, 1975, p.56:
"The attitude of the aerofoil, as expressed by the angle between the chord line and the free stream velocity vector ... , denoted by $\alpha$, is called the incidence, or angle of attack."
In contrast to Kermode, Clancy goes on to use "incidence" throughout.
The current question: while there's no question that "angle-of-attack" is often used to describe the angle between a wing chord line and the flight path/ relative wind, when we are talking about a whole aircraft, "angle-of-attack" is apparently sometimes used to describe the angle between the longitudinal axis of the aircraft and the flight path/ relative wind.
Regardless of whether or not all the statements above are entirely correct, I would like to know--
In one of the two possible British usages of "angle-of-incidence", specifically when it is NOT being used to indicate the "rigger's angle of incidence" between the mean chord line and the longitudinal axis of the fuselage, in the whole-airplane context, is there a default presumption that it means the angle between the longitudinal axis of the fuselage and the flight path/ relative wind, or is there a default presumption that it means the angle between the wing chord line and the flight path/ relative wind, or is there no default presumption as to which of these two alternatives is intended?
By "default presumption" I mean the most common usage or the usage which is least in need of extra clarification to the reader as to what is intended.
The question is not intended to get into the distinction of measuring relative to the free-stream airflow/ flight path/ relative wind versus the local airflow-- that's another thing that may depend on context-- just the distinction of measuring from the wing rather than from the fuselage.
As an aside, I have been informed that that the French phrases for these terms are used in different ways, with "angle d'attaque" referencing the angle between the flight path/ relative wind and the fuselage, and "angle d'incidence" referencing the angle between the flight path/ relative wind and the wing. But, we can explore the veracity of that idea in some other question.
Clarification -- it seems likely that the usage of "angle of incidence" I'm referencing in this question is now confined to aerodynamics/ design textbooks, papers, etc, and not in widespread usage in the pilot community in Britain. It's not something you'll find in a current study guide for a private pilot ground school or written exam, as the American terminology has now become universal there, using "angle of incidence" to mean the angle between the mean chord line of the wing and the longitudinal axis of the fuselage. That's not the usage of the term that this question is asking about.
