Rather than "powered flight", it might be better to talk about "heavier-than-air flight". If you used this concept to create a shell around a neutrally bouyant

Rather than "powered flight", it might be better to talk about "heavier-than-air flight". If you used this concept to create a shell around a neutrally bouyant blimp, then you could (in theory) move it through the air without at all disturbing the prevailing air currents in the area it was moving through. You would generate some turbulence as you were getting up to speed or changing course, but when you're not doing that you wouldn't need to exert any net force on the air.