At 260 knots, what happens to the green system pressure?

At 260 knots, what happens to the green system pressure?

• A. Isolated via a safety valve
• B. Activated by gear down
• C. Increases system pressure
• D. Drops to zero

Answer: (A)

High-speed protection in the hydraulic green circuit is provided by an automatic safety valve. When the aircraft reaches around 260 knots, this valve closes to isolate the green system from the rest of the hydraulic network, keeping its pressure within safe limits even as the pump continues to push fluid. This isolation prevents overpressure or crossfeed issues and preserves control authority. The other ideas don’t fit the scenario: gear down isn’t what triggers this isolation at that speed, the system isn’t meant to deliberately increase pressure at 260 knots, and it isn’t supposed to drop to zero under normal high-speed operation.

High-speed protection in the hydraulic green circuit is provided by an automatic safety valve. When the aircraft reaches around 260 knots, this valve closes to isolate the green system from the rest of the hydraulic network, keeping its pressure within safe limits even as the pump continues to push fluid. This isolation prevents overpressure or crossfeed issues and preserves control authority.

The other ideas don’t fit the scenario: gear down isn’t what triggers this isolation at that speed, the system isn’t meant to deliberately increase pressure at 260 knots, and it isn’t supposed to drop to zero under normal high-speed operation.