PAUSE IN ROTATION: ALL JET TRANSPORTS
The reason why so many rotations in large transport jets pause around the 8-10 degrees nose up attitude has absolutely NOTHING to do with the elevator being in close contact with the ground.That (according to Mr Boeing- I asked him), is just rubbish.When the WHEELS ARE ON THE GROUND the weight vector (remember from your PPL days?) goes through the wheels.Once the wheels leave the ground (757/767 8 degrees roughly) the weight vector of the whole airplane MOVES FORWARD TO THE CENTER OF PRESSURE ON THE WING.This causes a slight NOSE DOWN effect, stopping or slowing the rotation unless THE PILOT AVOIDS THIS BY INCREASING THE back pressure slightly to KEEP THE ROTATION RATE CONSTANT............ Pete