Originally Posted by
dogsridewith
Doesn't something called "ground effect" enhance lift below some very low altitude? So wouldn't that, plus lower Cd due to gear up, make very low flight above a runway a good place to accelerate? And wouldn't a low-nose attitude sort of facilitate this low flat flight regime? And reduce tire wear, in comparison to developing pre-rotation velocity in normal fashion?
Ground effect peters out above 1/2 wing span or so.
Note that the B-52 has HUGE flaps, effectively increasing the angle of attack well above the wing's angle of incidence. Combined with ground effect, the B-52 can indeed climb away from the ground with a flat (or even negative) fuselage attitude.
"Very low flight" may be a good place to accelerate theoretically, but proximity to the ground also makes it more dangerous and subject to often-uncontrollable outside influences (birds, turbulence...) that may tend to reduce altitude to 0.