stall and surge is caused when the flow in the compressor loses enthalpy and static energy so that it does not have enough power to approach the end of the axis; thus it remains in the annolus of the compressor and creates a stall cell. these cells gradually join each other and create stall zones which are rotating about the axis and are some times called rotating stall. if this stage does not get stopped, the stall cells will cover the whole annolus and will stop the fluid flow through the stages of the compressor and finally lead to surge. if surge happens, the compressor will be out of order.

Compressor stall and a wing stall are different and unrelated.

Compressor stall refers to the compressor section of a jet engine. The compressor section is comprised of several spinning round discs attached to a shaft that runs through the engine. Blades attached to each disc compress the intake air, which is later mixed with fuel and burned in the combustion chamber. If the intake flow of air is disrupted, compressor stall can occur, allowing high pressure gasses to move forward through the engine, making a loud banging noise. Compressor stalls are usually momentary and do not cause any damage or significant reduction in power.

A wing stalls when the angle between the chord of the wing and the relative wind becomes excessive and the airflow over the top of the wing is disrupted. The disruption results in a sudden loss of lift and the aircraft will descend and may become uncontrollable.

check to see if a/c compressor is locked up.

The ac compressor pump may be seized.