A question about Hydraulic Preasure.

[PSC13]

I had tried to fly F-4E with no fuel, and engine malfunction, compressor stall.

Then I can see the PC-1 and PC-2 are zero, and Engine RPM is also zero.

But I can still fly the plane, everything controllable. Every parts move as normal.

I am not sure if this is a problem, since I had already made many mistakes, something are just designed to be like that.

But I don't know why it is controllable. Did any one know that?

PS：Once I landed it, I will be unable to control soon, no parts can move any more.

[Jef Costello]

My guess this is not normal, no hydraulic pressure no flight controls and Martin Baker is your friend!

[Ivandrov]

So, first of all, the hydraulic pressure gauges require generator power to function. You can test this by turning off both generators in flight and the hydraulic gauges will drop to zero despite the engines still being on and providing hydraulic pressure. The Gens don't provide enough voltage while just windmilling and so the pressure reading also drops to zero.

There's an electrically driven pump that is supposed to provide some hydraulic pressure to the PC-1 side of the Stabilator in the event that hydraulic pressure drops below about 1000 psi.

Even then, if you are in the air, it is likely the engines are windmilling and providing some hydraulic pressure through that avenue as well.

And even then if there isn't any pressure at all, the flight controls are still connected mechanically.

Edited 18 minutes ago by Ivandrov