Hi Flaperon75,
But without the hydraulic fire shut off valve closed, what are the differences??
The windmilling engine will deliver 3,000 psi Hyds when the demand is low and airspeed is above green dot. Around GD speed, the pressure tends to fluctuate causing the PTU to cycle on and off and the HYD SYS page to cycle into view. Below GD speed, the PTU runs continuously so no more distracting SYS page changes.