u/philosopherssage:

>The vast majority of lift comes from near the tips of the blades. The transition from subsonic to supersonic is where the pressure from the moving object is greater than the fluid pressure (air). When this happens vacuum bubbles form and contact with the fluid is lost preventing the transfer of force. This is why lift is lost when the portion of the prop/rotor goes supersonic. The little bubbles also cause many shockwaves and can damage the surface, underwater this is called cavitation. The bubbles also disturb the flow of air and causes turbulence which even further reduces lift.

Cavitation flow is distinctly different from compressible flow in gases, as it involves a local phase change from the bulk liquid into its gaseous state. No 'vacuum bubbles' are formed in either case. In the case of wings, normal shocks on top of the wing cause flow separation, this is called wave drag which leads to loss of lift or in case of rotors or propellers, loss of thrust.