Originally Posted by
Vessbot
Exactly, and this is the flip side of all the non-wing "total airframe" components I mentioned that make any zero-AOA datum, arbitrary. So you might as well choose a convenient one, that is not separated, as you note, by the AOA vanes by a floppy piece of structure (and, I'll add, from the IRS).
This I disagree with. Why can't a plane be designed for the cruise condition with an exactly-level fuselage attitude (least drag) and wing incidence set for an AOA that yields best performance?
(I understand that after the basic design is "locked in" and it would be too time consuming and expensive to change the incidence, customer requirements or fuel prices or max gross weight or many other factors could change the cruise condition, and therefore the AOA, and therefore fuselage attitude; but I'm talking about the design process at the very beginning, before it's molested by such changes.)
No airplane can fly with zero AoA. Let’s don’t do Bernoulli. If the centerline of chord is the same as the fuselage longitudinal line, and the fuselage is level, the airplane will sink. The angle of incidence of the wing allows less nose up when close to level. It is “baked in” AoA. No?
There was an aircraft with “variable incidence wing”. It allowed Nose Down level flight, or even very Nose Down glide slope. It was useful for seeing the deck on the aircraft carrier when landing. Vought F-8 Crusader.