Hi,
h3dxb, It's not quite so simple as that - and FCOM doesn't give much guidance.
During the first engine start - the PTU does not run even when there's a pressure difference of 3,000 psi between Green & Yellow systems. This allows quicker start up of the engine by removing unnecessary drag from extra hydraulics. During the second engine start, the PTU is allowed to run - but it stops once the hydraulic pressure on the second engine is within the figure you quoted. So the PTU has now been tested.
MB2002. Affirm. On a previous, very sophisticated aircraft (L1011), I seem to remember we tested the ATMs (air turbine motors with a hydraulic pump) and the PTUs after engine start - and it was all described perfectly in the OPS manuals.
I've noticed in the sim, on the ground and with an engine failed - the PTU does not run when the parking brake is set! Where is that mentioned in FCOM?
Last edited by rudderrudderrat; 25th Feb 2010 at 13:43.
Reason: tech term