How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to the ground on the approach?
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.