G500 Hydraulic System Abnormals

- James Albright

These procedures are mostly CAS driven and straightforward in execution.  The only real “gotcha” is finding the correct procedures.  Some of the CAS messages are found starting in the “Caution” or “Warning” tabs and concluded there.  Some take you to procedures in the “Quick Reference Procedures” section.  One procedure, the right system failure, is buried inside the “Hyd System Fail, L-R (U)” Caution section.  If you follow the trail led by the CAS you should end up at the right procedure.

1)    “Hyd Pump Fail L (U)” Amber CAS, under the AFM “Caution” Tab

  • Means you will be without the left thrust reverser and midboard spoilers.

  • Sends you to the “Left Hydraulic System (L SYS) Failure – Loss of Pressure Only” procedure found in the the AFM “Quick Reference Procedures” Section, “Fuel/Hydraulics” Button

 2)    “Hyd Quantity Low, L-R” Amber CAS, under the AFM “Caution” Tab

  • Sends you to one of the three procedures found in the the AFM “Quick Reference Procedures” Section, “Fuel/Hydraulics” Button

3)    “Hyd Reservoir Hot, L-R” Amber CAS, under the AFM “Caution” Tab

  • Occurs if the indicated reservoir is above 107°C but below the Red CAS threshold

  • Means your autothrottles will be inhibited, the automatic mode of the Aux pump will be unavailable in the case of a left reservoir hot, and the PTU will be unavailable in the case of a right reservoir hot.

  • Directs you to bring the throttle to idle.  For a left system, the procedure allows you to continue flight if the reservoir is “hot, but stabilized.”  It does not make this statement for the right system but does direct the PTU be unarmed if not needed.

 4)    “Hyd System Fail, L-R” Amber CAS, under the AFM “Caution” Tab

  • Occurs if the indicated system’s pressure and/or fluid quantity have failed.

  • Means you will have lost some of your flight control surfaces, which restricts you to 285 CAS / 0.90 M.

  • Directs you to check the synoptic to figure out which procedure to follow.  The dual failure and left system scenarios are in the “Quick Reference Procedures” section.  The right system scenario has a hot link and isn’t found anywhere else but here.

 5)    “Hyd Reservoir Hot, L-R” Red CAS, under the AFM “Warning” Tab

  • Occurs if the indicated system’s temperature “exceeds limits,” given as 135°C in the Maintenance Manual’s System Description Manual.

  • Means your autothrottles will be inhibited, the automatic mode of the Aux pump will be unavailable in the case of a left reservoir hot, and the PTU will be unavailable in the case of a right reservoir hot.

  • Directs you to bring the throttle to idle, time, and shut the engine down if the message remains after 30 seconds.

 6)    “Dual Hydraulic System Failure – Loss of Pressure Only” procedure, under the AFM “Quick Reference Procedures” Section, “Fuel/Hydraulics” Button

  • Means you no longer have inboard and midboard spoilers, the PTU, or the thrust reversers.  You will have your primary flight controls and outboard spoilers in EB mode.  You will have flaps, nose wheel steering, landing gear, inboard brakes and the main door via the Aux pump.  You will have outboard brakes down to accumulator pressure.  All of this means you are restricted to 285 CAS / 0.90 M.

  • Directs you to check the synoptic Aircraft without FCC v9 must land as soon as possible.  Aircraft with FCC v9 are told to land at the nearest suitable airport no more than 4 hours after the failure occurred, if the failure occurred within 2 hours after takeoff.  In either case, the PTU and AUX pump are turned off, the approach is made with Flaps 20, a crosswind of less than 10 knots is desired, flaps down after the gear, and the Aux pump is turned on 1 minute prior to landing.  The Aux pump should be able to handle braking and nosewheel steering.

 7)    “Dual Hydraulic System Failure – Loss of Pressure and Fluid” procedure, under the AFM “Quick Reference Procedures” Section, “Fuel/Hydraulics” Button

  • Means you have less than 1600 psi and 0.3 gallons (left), 2350 psi and 0.3 gallons (right).  This means you have lost: autothrottles, aux pump, flaps, inboard and midboard spoilers, normal landing gear extension, nose wheel steering, the PTU, and the thrust reversers.  You will have primary flight controls and the outboard spoilers in EB mode.  You will have accumulator pressure on the inboard and outboard brakes.

  • Directs you to check the synoptic Aircraft without FCC v9 must land as soon as possible.  Aircraft with FCC v9 are told to land at the nearest suitable airport no more than 4 hours after the failure occurred, if the failure occurred within 2 hours after takeoff.  In either case, the PTU and AUX pump are turned off, the approach is made without flaps, 200 KCAS is minimum until WAI is on, alternate gear extension is used, and braking is accomplished with the precautions needed when braking on accumulator pressure only.

 8)    “Left Hydraulic System (L SYS) Failure – Loss of Pressure and Fluid” procedure, under the  AFM “Quick Reference Procedures” Section, “Fuel/Hydraulics” Button

  • Means you have less than 1600 or greater than 3449 psi and less than 0.3 gallons.  This means you have lost the aux pump, flaps, normal landing gear extension, nose wheel steering, midboard spoilers, the PTU, and the left thrust reverser.  This restricts you to 285 CAS / 0.90 M maximum.

  • Directs you to check the synoptic Aircraft without FCC v9 must land as soon as possible.  Aircraft with FCC v9 are told to land at the nearest suitable airport no more than 4 hours after the failure occurred, if the failure occurred within 2 hours after takeoff.  In either case, the PTU and AUX pump are turned off, the approach is made without flaps, 200 KCAS is minimum until WAI is on, alternate gear extension is used.

 9)    “Right Hydraulic System (R-SYS) Failure – Loss of Pressure and/or Fluid” procedure, found at the bottom of the “Hyd System Fail, L-R (U)” procedure

  • Means you have less than 2350 or greater than 3450 psi and less than 0.3 gallons.  This means you have lost the inboard spoilers, the PTU, and the right thrust reverser.

  • Directs you to check the synoptic Aircraft without FCC v9 must land as soon as possible.  Aircraft with FCC v9 are told to land at the nearest suitable airport no more than 4 hours after the failure occurred, if the failure occurred within 2 hours after takeoff.  In either case, the landing is normal except it is made without the right thrust reverser.