Dual Hydraulic System Failure - Loss of Pressure Only
This is a work in progress
The left HYD pressure is less than 1600 PSI and right HYD pressure is less than 2349 PSI.
- Aircraft Operating Envelope: 285 KCAS / 0.90M maximum.
- Flight Controls and Outboard Spoilers: Operative in EB Mode.
- Flaps, NWS, Landing Gear, MED: Operative with AUX pump only.
- Inboard Brakes: Operative with Aux Pump or Accumulator Pressure.
- Inboard and Midboard Ground/Flight Spoilers: Inoperative.
- Outboard Brakes: Accumulator Pressure Only.
- PTU: Inoperative.
- Thrust Reversers: Inoperative.
- Airspeed . . . 285 KCAS / 0.9M maximum
- Hydraulic Synoptic / Quantity . . . Check (pressure and fluid)
- If hydraulic failure occurred within 2 hours of takeoff:
- Airplane . . . Land at nearest suitable airport no more than 4 hours after the hydraulic failure
- If hydraulic failure did not occur within 2 hours of takeoff:
- Airplane . . . Land as soon as practicable
- Once the landing airport has been determined:
- PTU . . . NOT ARMED / OFF
- AUX PUMP . . . ARMED / OFF
- Right Brake Accumulator Pressure . . . Check
- If Right Brake Accumulator pressure is below 2000 psi:
- If Right Brake Accumulator pressure is above 2000 psi:
- FLAPS . . . 20°
- Crosswind . . . Less than 10 knots (if possible)
- LANDING GEAR / Lights . . . DOWN / 3 green
- If Nose Gear Door Open (caution) and / or L-R Main Gear Door Open (caution) CAS messages are displayed:
- FLAPS . . . 39°
- Airspeed . . . VREF+10 KCAS minimum
- Approximately 1 minute prior to landing:
- AUX PUMP . . . ARMED / ON
- To maintain directional control on landing:
- Brakes / NOSEWHEEL STEERING . . . Use
IF A HYDRAULIC SYSTEM FAILURE OCCURS WITHIN 2 HOURS AFTER TAKEOFF, LAND AT THE NEAREST SUITABLE AIRPORT NO MORE THAN 4 HOURS AFTER THE FAILURE OCCURRED. CONTINUING FLIGHT IN EXCESS OF 4 HOURS COULD RESULT IN A FLIGHT CONTROL SURFACE FAILURE, AND A LOSS OF AIRCRAFT CONTROL.
(1) Go to Step 5.
Hydraulic fluid temperature has stabilized, and flight control surface failure is not a concern.
Landing distance should be based on VREF +10 KCAS to touchdown.
Wheel fuse plug release may occur due to added landing speed under combinations of high field elevation, landing weight and OAT.
(1) Landing Distance . . . Recalculate with a 1.95 factor
(1) Landing Distance . . . Recalculate with a 1.56 factor
For landing gear and flap operation after takeoff or during approach, only one system at a time should be operated to allow the cycle to complete before operating the next system.
Flap and landing gear operation using only the AUX PUMP will result in a temporary Aux Hyd Pump Fail (caution) CAS message when the pressure drops to less than 850 PSI.
(1) AUX PUMP . . . ARMED / ON
(2) AUX PUMP . . . ARMED / OFF (once Gear Door CAS messages are no longer displayed)
NOSE DOWN STICK INPUT MAY BE REQUIRED AFTER TOUCHDOWN TO LOWER THE NOSE.
The outboard brake accumulator pressure will not be replenished. When the outboard brake accumulator pressure is depleted, continued operation and braking will be performed only with the inboard brakes.
Gulfstream GVII-G500 Airplane Flight Manual, Revision 1, August 31, 2018