Admiral346, yet again you come over as a know-it-all, when your level of knowledge doesn't support your claims...
Some APU's can be started throughout the full flight envelope - Assuming the fuel supply is not exhausted, and is the reason the engines stopped working in the first place.
Many engines will provide enough hydraulic power through windmilling alone.
Saying 50psi is not enough to power hydraulics is plain daft.
Do you understand the difference between pressure and flow rate? Can you appreciate how a pump being driven by a low pressure but high flow rate can produce 3000psi?