Originally Posted by bearfoil
BEA are confusing AoA with Deck Angle.
Deck angle is the angle between the longitudinal axis and the horizontal plane. For aerodynamicists, performance engineers, and airplane systems, when considering the whole airplane rather than a particular section of the airplane's wing, the longitudinal axis is the reference for AoA and pitch attitude.
Boeing Jet Transport Performance Methods, Chapter 10 - Wings:
Some airplanes have wings which are twisted such that the angle of incidence at the root of the wing is different from the angle at the tip. This is usually done to enhance the stalling characteristics of a wing, or to tailor the lift distribution. The wing of the 747, for example, is twisted by 3.5 degrees, having an incidence of 2 degrees at the root and -1.5 degrees at the tip.
regards,
HN39