Originally Posted by
Asturias56
Incidence - the angle between the wing chord line and the free air stream (also referred to as "angle of attack")
Ok, thanks. Could this be a difference in UK vs US terminology?
In my search for definitions of both terms I stumbled across this "Flight Test Engineering Handbook" originated at Edwards in May 51 and revised much later. It contains only one reference to "incidence" and numerous references to "angle of attack".
https://apps.dtic.mil/sti/tr/pdf/AD0636392.pdf