The Evolution of Aviation Terms - Angle of Incidence

[cm575]

Another thing I've noticed in reading contemporary texts is that the term "angle of incidence" is used for both the static angle of the chord on the aircraft and the variable angles due to manipulation of the aircraft's controls.

In later years it seems like there was a division and "angle of incidence" became to exclusively describe the static angle of the chord while "angle of attack" began to be used to describe the variable angles through manipulation.

Once again, does anyone know when this change was made?

According to that ever-reliable source Wikipedia, "angle of incidence" is still sometimes used in British English to denote variable angles. It also is said that this is used in aeronautical engineering to describe these variable angles.

I also noticed that in the glossary to White's Practical Aviation (1918) that the entry for "critical angle" has the French translation of "angle d'attaque", and, in his definition, White uses "angle of attack" for the first time I've ever seen in a contemporary text. His definition, of course, is something different from the modern usage, though. For him this "angle of attack" is the critical angle above which no more lift is possible.

Thank you for any help.

[Barrett]

Very few aeronautic types today give any thought to what a hewge debt we owe the French for our vocabulary:
Aileron
Fuselage
Empennage
Nacelle
and maybe Elevon
Plus undoubtedly more.

[cm575]

Originally Posted by Barrett

Very few aeronautic types today give any thought to what a hewge debt we owe the French for our vocabulary:
Aileron
Fuselage
Empennage
Nacelle
and maybe Elevon
Plus undoubtedly more.

Thank you for a response.

No one seems as interested in this topic as I am!

It does seem that in these early days of aviation that France was well ahead of other places, and many English terms do seem to derive from French.

Perhaps "angle of attack" does, in fact, derive from the French term for "critical angle".

[cm575]

I suddenly had a good idea.

I searched through the archives of Flight magazine, and I was shocked to discover many uses of the terms "angle of attack".

I was able to find the earliest use of this in print, which was in the November 6, 1909 issue.

There's a small article about some instruments available for "aeronauts":

A LEVEL AND WIND INDICATOR FOR FLYERS.—

The above photograph illustrates an interesting instrument which has been designed for use on flying machines by M. Arnoux, the Vice-President of the Technical Committee of the A.C.F. It indicates the force of the wind, the inclination of the machine, and the " angle of attack " when ascending or descending.

Fascinating! This term was being used at least as early as 1909. I'm curious, then, why most World War I era books used "angle of incidence" instead.

[Froggy]

Bonjour

In fact the English term coming from French 'angle of attack' is in French 'angle d'incidence'

Cordialement
Bruno