by rainboe:
Fall below a certain speed and the windmilling speed may not provide the hydraulic power you need to operate your flying controls and flaps- possibly about 160kts airspeed. In fact operate flaps and you may then lose flying controls with no pressure left for them!
With all respect,
Can someone confirm that the FARs would allow this condition? From what I've quickly gleaned (Gimli Glider) the RAT should always provide enough hydraulic pressure for the primary control surfaces.