RetiredF4:
Is the A320 series different?
Yes it is. It doesn't carry fuel, doesn't act as a trim tank.
Me:
The THS on almost
heavy aircraft has a positive profile. That is why the
"ground set" is minus 4º, (zero lift). Remember that the A330/340 family (and others) carry 5 Ton of fuel in the trim tank (that is why THS, with trim tank full, flies at minus 3º - only 1º above ground zero set - and this is done) to save about 3% of fuel, due to less drag.
Also, the reason why the elevator flips 30º up and only 15º down is due to the fact that it needs a higher degree up in order to destroy positive lift created by the THS curved wing.
I was speaking of heavy aircraft on the Airbus family.
HazelNuts39:
Just to confuse things a little, D.P. Davies' book uses the name "angle of incidence" for that same angle. However, for many others "angle of incidence" is the angle between the "wing chord" and the longitudinal reference axis. That angle may be meaningful for light aircraft with a straight, constant section, untwisted wing. It is not meaningful for the swept, twisted wings with variable section that are used on modern large transport aircraft. If you want to apply it to the airfoil section in mm43's drawing, the angle of incidence of the horizontal tail as drawn is -13 degrees
None of your pictures shows an undoubtedly lower camber on an A330/A340 aircraft. I've seen most of those pictures before you have posted them here. I've done my research also, and I have found no good picture to post also.
Remember these are twisted wings with variable section.
Would you say that
this wing has an upper camber if you didn't know?