""there was also the suggestion that the planes did not sink toward the nose as "maybe"might be expected.""

That one is easy. Planes are not, (as you might intuitively expect, heavy at the nose because of the engine.

Aircraft centre of gravity is very much in the centre of the craft, or it would be hopelessly nose heavy and impossible to control in the air.

Also you would see lots of planes parked nose down.

They will always tend to sink level, unless some other object intervenes.

Don T.