[mechhacker]

IIRC that is due to other issues, not aerodynamics.

For instance, the engine no longer receiving oil at negative 1 g, or fuel, as the system is designed for gravity flow.

Stunt planes and airplanes capable of long inverted flight need special oiling and fuel systems to keep the engine from starving from either.

[itishappy]

Fascinating! Commercial airliners have also optimized their engines enough they don't have the power budget to make up for the difference in lift.