Would compression speed even be possible? One would have to have the ability to keep the plane in the in the 90 to ground flight path.
I suppose it could be, but it would take a lot of alt to do it I would think. Thus you would have the ability to recover.
Compression (actually exceeding critical mach number for the airfoil. Compression is an archaic term) is certainly possible assuming you could control the aircraft going backwards.
Viscous fluids accelerate along a curve. You are essentially describing flying the airfoil backwards. The situation is akin to a supercritical airfoil. You would present a flat upper surface with a sharp leading edge to the fluid flow. The biggest issue is the blunt, highly curved rear third of the wing (the leading edge in normal flight). Flying backwards the acceleration along the upper surface would be slow until reaching the highly curved portion, rapidly accelerating the upper surface fluid, reaching critical mach number pretty quickly.
Most likely the center of pressure on an airfoil such as the Corsair flown backward would be very close to the maximum thickness point(SWAG ALERT). The resulting shockwave of the rapidly accelerating air reaching the curve would quickly push the center of pressure off the airfoil entirely, resulting in a violent departure from controlled flight.
This is, of course, all very theoretical as control of an aircraft going backwards would be impossible for a human. You would need a fly by wire system programmed to do it (Assuming you built the aircraft to handle the stresses of such an event)
