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Hydraulics System Abnormals

Gulfstream G450 Abnormals


 

Left and Aux System Loss of Fluid

The hardest part about this procedure is having enough patience with the parking brake. Think of the many times you've landed the airplane and didn't touch the brakes until taxi speed.

  • Plan a long final approach to get the landing gear extended using the emergency system.
  • Put the airplane down firmly to kill kinetic energy.
  • While you still have rudder effectiveness, drift the airplane to the downwind side in anticipation of the aircraft weathervaning into the wind once you lose rudder effectiveness.
  • Slowly pull the parking brake until pressure is indicated, about a quarter of an inch. Use your thumb as leverage to avoid jerkily pulling past that quarter of an inch. Slowly work your way up to 400 and then leave it there. As the brakes heat up that same pressure will become more and more effective. You shouldn't have to go above that until you are at taxi speed. If you've never heard the "20/30/40 technique" on how to judge braking effort, you should consider it just to give yourself an idea about how much braking effort you really need: The Left Seat for the First Time / Braking Effort. (Even if you've been flying for decades you may have never heard this. It can really help.)

Symptoms:

The synoptics may show a loss of fluid and lack of system pressure.

Besides the Hydraulic System Fail, L-R you could also have one or all of the following:

Aux Hydraulic Fail

Hydraulic Quantity Low, L

Hydraulic System Fail, L

Analysis:

You cannot be certain about left system hydraulic quantity with the gear handle up because the system adds a gallon to the synoptic to compensate for the fluid in the landing gear actuators in the up position. An indication of around a gallon could indeed be a gallon or it could be no fluid at all. That could also mask the actual quantity in the AUX portion of the reservoir. So there are two philosophies we can use at this point:

  1. Assume the AUX portion is empty, plan a landing based on that, and once you've landed try the brakes. It could be that you have just enough fluid to bring the airplane down to taxi speed or even to a stop. If that doesn't happen, revert to emergency braking. This is the method selected in the G550.
  2. Test the AUX pump for 30 seconds. If it holds pressure for 30 seconds assume it is going to work and switch to the checklist for loss of left system pressure and fluid (but not for loss of the aux pump). If it doesn't hold pressure, get ready for emergency braking. This is the method selected in the G450.

I would be very tempted to choose the G550 method in the G450. Regardless of your choice, you should have a game plan for landing without left or aux hydraulic system fluid. The airplane flies perfectly well until it comes times to land. You will need to extend the landing gear with the nitrogen bottle, accept whatever flaps you have, and stop using the emergency braking system.

Procedures:

[G450 AFM, §4-15-20]

    Continue flight to nearest suitable airport and land.

    CAUTION: TO VERIFY THE AVAILABILITY OF AUXILIARY SYSTEM FLUID, SELECT THE AUX PUMP ON FOR A MINIMUM OF 30 SECONDS AND CHECK FOR AUXILIARY SYSTEM PRESSURE. IF PRESSURE CAN BE MAINTAINED, ASSUME THAT THE AUXILIARY SYSTEM IS AVAILABLE AND PROCEED TO Left Hydraulic System (L SYS) Failure – Loss of Pressure and Fluid, PAGE EE-8.

  1. FGC Selection . . . FGC 2
  2. PTU . . . NOT ARM
  3. AUX PUMP . . . CHECK OFF
  4. Approach:

    Select a runway that is at least 7,000 feet long and 150 feet wide. Minimize crosswind component to less than 5 knots if possible. If crosswind is present, plan the landing on the downwind side, as the airplane will weather vane into the wind as rudder effectiveness is lost. Plan a shallow approach to land within the first 1,000 feet of the runway.

  5. GPWS/GND SPLR FLAP ORIDE . . . ON / AS REQUIRED
  6. Select the ORIDE switch to ON if landing with flaps less than 22°. This prevents the nuisance “TOO LOW FLAPS” aural alerts.

  7. NWS POWER . . . OFF
  8. Airspeed . . . 175 KCAS OR LESS
  9. Landing Gear Handle . . . DOWN
  10. Emergency Landing Gear Handle . . . PULL
  11. CAUTION: DO NOT RESET EITHER THE EMER GEAR HANDLE OR THE DUMP VALVE PRIOR TO LANDING.

  12. Landing Gear. . . DOWN / 3 GREEN
  13. Anti-Skid . . . OFF
  14. Ground Spoiler . . . OFF
  15. Brakes System Page . . . SELECT
  16. VREF . . . APPROPRIATE TO CONFIGURATION
  17. Plan a wide approach and observe VREF speed appropriate to configuration as shown in AFM Section 5: Approach and Landing, Normal Final Approach and Landing Performance Data Table.

    Landing:

    After landing, deploy the right thrust reverser as required to slow the airplane, maintaining aerodynamic directional control with the rudder. Aerodynamic control will not be available below 60 knots and will begin diminishing at around 80 knots. Depending on winds, runway crown, etc. the airplane may veer as rudder effectiveness is lost. The right thrust reverser may mitigate a veer to the left. A slight thrust increase on the right engine (forward thrust) may mitigate a veer to the right but with a corresponding increase in landing roll. In either case, cautious application of reverse or forward thrust if required should only be considered if a runway departure is likely.

  18. Speed Brakes . . . EXTEND
  19. Right Thrust Reverser . . . DEPLOY / AS REQUIRED
  20. CAUTION: IT IS NORMAL FOR DECELERATION TO INCREASE AS THE STOP PROGRESSES. THIS MAY RESULT IN LOCKED WHEELS AND BLOWN TIRES. REDUCE PRESSURE AS REQUIRED TO MAINTAIN CONSTANT DECELERATION. THERE WILL BE A SIGNIFICANT INCREASE IN LANDING DISTANCE WITH ANTI-SKID INOPERATIVE.

  21. Park / Emergency Brake . . . AS REQUIRED TO MAINTAIN 400 PSI
  22. Slowly apply park / emergency brake, increasing pressure to 400 PSI. However, it may be necessary to exceed this pressure in order to stop the airplane on the runway. The pilot should devote his attention to airplane control and brake application, while the copilot should monitor applied brake pressure advising the pilot of corrections required to maintain optimum brake pressure.

    Slowly pull the parking brake until pressure is indicated, about a quarter of an inch. Use your thumb as leverage to avoid jerkily pulling past that quarter of an inch. Slowly work your way up to 400 and then leave it there. As the brakes heat up that same pressure will become more and more effective. You shouldn't have to go above that until you are at taxi speed.

    After Landing:
  23. Landing Gear Safety Pins . . . INSTALL
  24. CAUTION: GEAR PINS SHALL BE INSTALLED PRIOR TO RESETTING DUMP VALVE.

Left and Right System Failure

So you've lost the left hydraulic system but retained the fluid, and you've lost the right system. What if you lose the left fluid too? There is a checklist for that, but it isn't in the hydraulics section of the QRH. Turn to the "Engine Broke" section, EB-11, for the Right Engine Failure and Complete Left/Auxiliary Hydraulic Failure procedure.

So in this scenario at least you have the left system fluid and your aux pump works. Ask for a very long final with the least amount of crosswind on a long runway. You will need time to extend the landing gear and to get used to flying with manual reversion. We used to practice this at Andrews in the GIII before wiser heads prevailed. It is a handful, even for someone who grew up with the dutch roll of a basic KC-135A. Oh yes, plant the airplane on the runway and make it a tricycle as soon as you can. You don't want to deal with the sloppy controls in the flare.

Symptoms:

Besides the Hydraulic System Fail, L-R you could also have Hydraulic Quantity Low, L-R and others. The synoptics page may reveal reduced or absent quantities and pressures.

Analysis:

Without left or right hydraulic systems you will end up flying the aircraft in manual reversion, extending the landing gear with the nitrogen bottle, and using the aux pump to partially extend the flaps and provide wheel brakes. Remember the aux, even if you have the 2 gpm version, cannot drive the brakes while driving the flaps. So you need to get the flaps into position and leave them there before landing.

Procedures:

[G450 AFM, §4-15-10]

    In the event of a dual hydraulic failure, the airplane is controllable due to the manual reversion capability of the flight control system. With the loss of both systems, the yaw damper is inoperative. Slow to 0.80 MT or 250 knots and descend as soon as practical.

    Continue flight to nearest suitable airport and land.
  1. YAW DAMP . . . OFF
  2. PTU . . . NOT ARM / OFF
  3. Altitude . . . ESTABLISH 25,000 FT OR BELOW
  4. Airspeed . . . MAINTAIN 250 KTS OR SLOWER
  5. For approach and landing, plan a wide, power-on approach.

    Once established:
  6. AUX Pump . . . ON
  7. Flaps . . . 20°
    20° flaps should be planned for approach and landing.
  8. Airspeed . . . MAINTAIN 175 KCAS MAXIMUM
  9. Landing Gear Handle . . . DOWN
  10. EMER Gear Handle . . . PULL
  11. CAUTION: DO NOT RESET EMERG LDG GEAR HANDLE OR DUMP VALVE FOR REMAINDER OF FLIGHT.

  12. Landing Gear . . . DOWN / 3 GREEN
  13. Flaps Position . . . VERIFY 20°
  14. GPWS/GND SPLR FLAP ORIDE . . . ON
  15. Select the ORIDE switch to ON if landing with flaps less than 22°. This prevents the nuisance “TOO LOW FLAPS” aural alerts.

  16. VREF . . . APPROPRIATE TO CONFIGURATION
  17. NOTE: During approach to landing, a Ground Spoiler warning message may be displayed on the Crew Advisory System (CAS) during flap extension. This is due to floating of spoilers and is considered normal.

    Prior to touchdown:

    CAUTION: ENSURE THAT THE FLAPS HAVE REACHED 20-DEGREE POSITION PRIOR TO TOUCHDOWN. IF FLAPS ARE STILL IN TRANSIT, DELAY THE LANDING UNTIL THE FLAP MOVEMENT HAS STOPPED. IF UNABLE TO DELAY THE LANDING, PULL THE FLAP / STAB LEFT DC (POP, C-6 – SEE PAGE S-46) AND FLAP / STAB RIGHT DC (CPOP, C-6 – SEE PAGE S-46) CIRCUIT BREAKERS TO STOP FLAP MOVEMENT. PULLING THESE CIRCUIT BREAKERS WILL RESULT IN THE FOLLOWING CAS MESSAGES: Stick Push Unavailable, Flaps Failed, Stabilizer Failed, GPWS 1-2 Fail, Windshear 1-2 Fail, Emer Stab Maint Reqd, Flap/Stab Maint Reqd, A/T Inhibit AFCS - If attempting to select AUTOTHROTTLE

    PFD INDICATIONS: AOA DASHES (---), RED X ON FLAP/STAB INDICATION, AT 1-2 FLASHING RED IF AUTOTHROTTLES WERE ENGAGED, THRUST DIRECTOR DISSAPEARS. LANDING WITH THE FLAPS IN MOTION WILL CAUSE A LOSS OF BRAKES DURING THE LANDING ROLLOUT.

    Landing:

    NOTE: Thrust reversers, ground spoilers and nosewheel steering will be inoperative after touchdown.

  18. Brakes and Rudder . . . AS NECESSARY
  19. With both hydraulic systems failed, braking pressure will be supplied by the AUX hydraulic system. Expect diminished braking capability due to lower AUX Hydraulic Pump output capacity. If AUX hydraulic system pressure is lost, the PARK / EMERG brake must be used. Anti-skid will be inoperative when using the PARK / EMERG brake. See Anti-Skid OFF Braking, page EG-13 and Braking Using PARK / EMERG Brake, page EG-10.

    See: G450 Braking using emergency brake.

    After landing:
  20. Landing Gear Safety Pins . . . INSTALL
  21. CAUTION: GEAR PINS SHALL BE INSTALLED PRIOR TO RESETTING DUMP VALVE.

Left System Loss of Pressure and Fluid

This isn't too difficult so long as you plan a long final approach to get the landing gear extended using the emergency system and have enough runway to land with 20° of flaps. How much? Landing distance using 20° flaps and automatic ground spoilers is actually a little better than landing using 39° flaps and manual speedbrakes. If you add 10 percent to your normal landing numbers you will be in the ball park.

The G450 checklist is different than the G550 in that the G450 has you run the aux pump for 30 seconds to see if there is any fluid left to run the flaps and the G550 doesn't. "They" say this is because the G550 has a demonstrated weak spot in the nose wheel steering and if you want to see if that is so. I say that doesn't make a lot of sense. The G550's approach speed with flaps up is lower than the G450 with flaps 20, so it doesn't matter to them. But you might consider saving your precious 30 seconds of fluid for the landing. If, for example, the left system fluid leak was caused by the flaps you are landing without them so that is a done deal. Why not save that fluid for the landing roll out? If you only have 30 seconds of fluid why not use it for full anti-skid braking? If you run out of fluid (or there isn't any) you will end up on the emergency brake. But that would have happened under the 30-second scenario too. Just a thought.

Symptoms

Hydraulic Quantity Low, L

Hydraulic System Fail, L

The synoptics will show a loss of fluid and lack of system pressure.

Analysis:

The airplane can be configured, landed, and stopped using back up systems.

Procedures:

[G450 AFM, §3-15-30]

    Continue flight to nearest suitable airport and land.
  1. FGC Selection ... FGC 2
  2. Hydraulic Synoptic / Quantity ... DISPLAY / CHECK
  3. PTU ... NOT ARM
  4. If a hydraulic leak in the flaps system is not suspected, consider CAUTION and go to Step 5. Otherwise, disable flaps by performing Step 4.

  5. FLAP / STAB (L and R) DC CBs ... PULL
    FLAP / STAB PRI L DC: POP, C-6
    FLAP/STAB PRI R DC: CPOP, C-6
  6. CAUTION: TO VERIFY THE AVAILABILITY OF THE AUXILIARY SYSTEM FLUID, SELECT THE AUX PUMP ON FOR A MINIMUM OF 30 SECONDS AND CHECK FOR AUXILIARY SYSTEM PRESSURE. IF PRESSURE CANNOT BE MAINTAINED, ASSUME THAT THE AUXILIARY SYSTEM IS NOT AVAILABLE AND PROCEED TO Left (L SYS) and Auxiliary Hydraulic System (AUX) Loss of Fluid.

    If you've wondered why you need to wait 30 seconds to verify you have fluid you are not alone. Gulfstream changed this procedure in the G550 so that you assume the fluid is gone but arm the aux pump so that whatever fluid you do have will be available for braking. They haven't made the change in the G450 but it would seem prudent. Why waste 30 seconds of fluid when that may be all you need for landing?

  7. AUX PUMP ... SELECT ON FOR 30 SECONDS
  8. With a complete loss of Left Hydraulic System fluid and the gear handle selected up, the Left Hydraulic System reservoir will show approximately one gallon of fluid and the Auxiliary Hydraulic System reservoir will continue to indicate full. When the gear is selected down, the Left Hydraulic System reservoir will indicate zero (0) and an amber “X” will be displayed over the Auxiliary Hydraulic System reservoir. For either case, the only way to verify availability of Auxiliary System fluid is to select the Auxiliary pump on and observe that pressure can be maintained.

    If loss of L SYS fluid and AUX SYS fluid is suspected or has occurred, see Left (L SYS) and Auxiliary Hydraulic System (AUX) Loss of Fluid.

    For approach and landing:
  9. AUX Pump ... ON
  10. FLAP Handle (If CBs Not Pulled in Step 4) ... 20°
  11. Twenty degree (20°) flaps should be planned for approach and landing.

  12. Airspeed ... 175 KCAS OR LESS
  13. Landing Gear Handle ... DOWN
  14. Emergency Landing Gear Handle ... PULL
  15. CAUTION: DO NOT RESET EITHER THE EMER GEAR HANDLE OR THE DUMP VALVE PRIOR TO LANDING.

  16. Landing Gear... DOWN / 3 GREEN
  17. Flaps Position (If Available) ... VERIFY 20°
  18. VREF ... APPROPRIATE TO CONFIGURATION
  19. Plan a wide approach and observe VREF speed appropriate to configuration as shown in AFM Section 5: Approach and Landing, Normal Final Approach and Landing Performance Data Table.

    Prior to touchdown:

    CAUTION: ENSURE THAT THE FLAPS HAVE REACHED THE 20 DEGREE POSITION PRIOR TO TOUCHDOWN. IF FLAPS ARE STILL IN TRANSIT, DELAY THE LANDING UNTIL THE FLAP MOVEMENT HAS STOPPED. IF UNABLE TO DELAY THE LANDING, PULL THE FLAP / STAB PRI L DC (POP, C-6 – SEE PAGE S-46) AND FLAP / STAB PRI R DC (CPOP, C-6 – SEE PAGE S-46) CIRCUIT BREAKERS TO STOP FLAP MOVEMENT. LANDING WITH THE FLAPS IN MOTION DRIVEN BY THE AUXILIARY HYDRAULIC PUMP WILL CAUSE A LOSS OF BRAKES DURING LANDING ROLLOUT.

  20. GPWS/GND SPLR FLAP ORIDE ... ON / AS REQUIRED
  21. Select the ORIDE switch to ON if landing with flaps less than 22°. This prevents the nuisance “TOO LOW FLAPS” aural alerts.

    Landing:

    Note: The left thrust reverser will be inoperative.

  22. Speed Brakes ... EXTEND
  23. Brakes ... AS REQUIRED TO MAINTAIN DIRECTIONAL CONTROL
  24. Right Thrust Reverser ... DEPLOY / AS REQUIRED
  25. After Landing:
  26. Landing Gear Safety Pins ... INSTALL
  27. CAUTION: GEAR PINS SHALL BE INSTALLED PRIOR TO RESETTING DUMP VALVE.

Left System Loss of Pressure Only

This can be a non-event if you take things a little slower than normal. Just give each hydraulic component a separate bite at the hydraulic pressure. We used to worry about doing this with 39° of flaps in the event of a go around. The airplane appears to have more than enough power to allow a go around at 39° of flaps until the gear is fully retracted.

CAS

Hydraulic System Fail, L

Symptoms:

You may or may not get the CAS (the QRH seems to go both ways on this) but you should definitely see the PTU pressure come up if it was in AUTO. The synoptics should show a lack of pressure above the check valve that appears below the flight controls left side inputs.

Analysis:

If the fluid is retained but the pressure is not, you more than likely have a failed engine-driven pump. With the PTU operating, the only thing you've really lost is the left engine reverser. The flight controls normally lower hydraulic pressure to 1,500 psi; they will automatically allow the right system to provide a full 3,000 psi with the left system out so you should not notice any difference in the flight controls. The automatic ground spoilers will work with the right system providing pressure to the spoilers and the PTU providing pressure to the servos.

Procedures:

[G450 AFM, §3-15-40]

    Continue flight to the nearest suitable airport and land.
    1. FGC Selection ...FGC 2
    2. Hydraulic Synoptic / Quantity ... DISPLAY / CHECK
    3. PTU ... NOT ARM
    4. For approach and landing:
    5. PTU ... ON
    6. NOTE: For landing gear and flap operation after takeoff or during approach, operate one system at a time allowing completion of cycle before operating next system, for example:

      • Raise landing gear first, then retract flaps after gear is up after takeoff.
      • Allow flaps to reach 20° before lowering gear for approach and landing.

    7. AUX HYD PUMP ... ON
    8. Flaps ... 20°
    9. Landing Gear ... DOWN / 3 GREEN
    10. Flaps ... DOWN (39°)
    11. Ground Spoilers ... ARMED
    12. Landing:

      NOTE: The left thrust reverser will be inoperative.

    13. Brakes / Steering ... AS REQUIRED TO MAINTAIN DIRECTIONAL CONTROL
    14. Right Thrust Reverser ... AS REQUIRED

    Right System Loss of Pressure and/or Fluid

    The only thing you've really lost is the right engine thrust reverser so no real worries.

    CAS

    Hydraulic Quantity Low, R

    Hydraulic System Fail, R

    Symptoms:

    You may get one or both CAS messages and the synoptics should show a loss of pressure and/or quantity on the right system.

    Analysis:

    The only thing on consequence lost is the right engine thrust reverser. The flight controls normally lower hydraulic pressure to 1,500 psi; they will automatically allow the left system to provide a full 3,000 psi with the right system out so you should not notice any difference in the flight controls. The automatic ground spoilers will work with the left system providing pressure to the spoilers and to the servos.

    Procedures:

    [G450 AFM, §3-15-50]

      Continue flight to the nearest suitable airport and land.

      With a loss of R SYS fluid, the right engine shut down, the right engine FIRE handle pulled or right hydraulic pump failed, there is little degradation of performance. The only component not available is the right thrust reverser.

      In the event of R SYS failure:

    1. FGC Selection ... FGC 1
    2. PTU ... NOT ARM
    3. For Approach and Landing:

    4. AUX PUMP ... ON
    5. NOTE: For gear and flap operation after takeoff or during approach, operate one system at a time allowing completion of cycle before operating next system, for example:

      • Raise gear first, then retract flaps after gear is up after takeoff.
      • Allow flaps to reach 20° before lowering gear for approach and landing.
    6. Approach and Landing ... ALLOW FLAPS TO REACH 20° BEFORE SELECTING LANDING GEAR DOWN
    7. Landing Gear ... DOWN / 3 GREEN
    8. Flaps ... DOWN (39°)
    9. Ground Spoilers ... ARMED
    10. Landing:

      NOTE: The right thrust reverser will be inoperative.

    11. Brakes / Steering ... AS REQUIRED TO MAINTAIN DIRECTIONAL CONTROL
    12. Left Thrust Reverser ... AS REQUIRED

    Landing with the HMG

    CAS

    CAS messages will depend on the nature of the electrical system malfunction requiring use of the HMG.

    Analysis:

    You have more than likely been put into this situation by an electrical problem that will now compound your landing situation because the HMG is relying on hydraulic pressure to keep the electrical systems from dropping off line. Your biggest concern would be the surge of hydraulic pressure taken by the automatic ground spoilers after you land, so don't use them. But be gentle with the speed brakes too, the book says use at least 3 seconds to extend them.

    Procedures:

    [G450 AFM, §3-15-60]

      NOTE: Plan a 20° flaps landing.

      With both hydraulic systems available, and with the PTU and AUX pumps hard selected ON, there is sufficient hydraulic flow to prevent any HMG drop-offs throughout the configuration changes for a 20° flaps landing provided engine power is advanced for gear extension. The stab actuator is normally unpowered when operating on HMG power, so it will be necessary to select EMER STAB in order to operate the flaps.

      Avoid trimming with EMER STAB while the flaps are in motion as the additional electrical load from the stab actuator may cause drop-offs. Use manual pitch trim instead. Once flaps have achieved the desired position, EMER STAB may be used as required to trim out pitch forces. With the left hydraulic system available, it has been demonstrated that there is sufficient hydraulic flow to prevent any HMG drop-offs throughout the configuration changes for landing, provided speed brakes are used in lieu of ground spoilers on the rollout.

    1. AUX Pump ... ON
    2. PTU Pump ... ON (OFF IF R SYS UNAVAILABLE)
    3. EMER STAB ... ON
    4. Pitch Trim ... DISENGAGE
    5. Engine ALT CTL ... CHECK HARD SELECT (BLUE)
    6. NOTE: Use manual trim during flap extension.

    7. Flaps ... 20° FOR LANDING
    8. Flaps 20° ... CONFIRM
    9. Engine Power ... ADVANCE FOR GEAR EXTENSION
    10. NOTE: If PTU or right hydraulic system is unavailable, expect HMG drop-offs during gear extension.

    11. Landing Gear ... DOWN / 3 GREEN
    12. GPWS/GND SPLR FLAP ORIDE ... ON
    13. Ground Spoilers ... OFF
    14. After touchdown:
    15. Speed Brakes ... EXTEND SLOWLY (3 SECONDS MINIMUM)
    16. NOTE: The right thrust reverser will be inoperative if the right hydraulic system is unavailable.

    17. Thrust Reversers ... AS REQUIRED
    18. If go-around is necessary:

      NOTE: Consider leaving gear and flaps DOWN for a closed traffic pattern.

    19. Go-Around Power ... SET
    20. Gear ... LEAVE DOWN
    21. Be alert for HMG drop-off if gear is retracted.

    22. Flaps ... RETRACT AS NECESSARY

    Right Engine Failure and Complete Left/Aux Hydraulic Failure

    With the right engine starter providing windmilling hydraulics, this is just like landing with Loss of Left and Aux Fluid with the exception you need to turn the starter on in the last ten minutes. The hardest part about this procedure is having patience with the parking brake. Think of the many times you've landed the airplane and didn't touch the brakes until taxi speed.

    • Plan a long final approach to get the landing gear extended using the emergency system.
    • Putting the airplane down firmly kills kinetic energy.
    • While you still have rudder effectiveness, drift the airplane to the downwind side in anticipation of the aircraft turning into the wind once you lose rudder effectiveness. If you have a choice, having a wind from the left allows you to use right engine reverse to counteract the weather vane.
    • Slowly pull the parking brake until pressure is indicated. Slowly work your way up to 400 and then leave it there. As the brakes heat up that same pressure will become more and more effective. You shouldn't have to go above that until you are at taxi speed.

    Symptoms:

    The right engine has failed but is windmilling, the synoptics show you have no hydraulic pressure or quantity on the left.

    Analysis:

    You have hydraulic pressure on the right so long as the engine is windmilling, you can keep the pressure up through the landing using the right engine starter.

    Procedures:

    [G450 AFM, §4-06-80]

      NOTE: This procedure covers loss of both Left and AUX Hydraulic Systems with a windmilling right engine. Windmilling HP rpm as low as 2.7% provides sufficient flight control power for safe flight. Flight control inputs should be minimized (20° bank angles and ±10° pitch have been demonstrated) and a “No Flap” landing performed. If the windmilling engine was shut down using the FIRE handle, it will be necessary to reseat the handle to restore hydraulic power. Prior to reseating the FIRE handle, the R FUEL S/O circuit breaker will need to be pulled in order to prevent fuel from being introduced into the engine.

      CAUTION: IF FIRE HANDLE IS RESEATED AT HIGH ALTITUDE, HYDRAULIC PRESSURE MAY NOT BE RESTORED UNTIL DESCENDING TO LOWER ALTITUDES. MAXIMUM RECOMMENDED ALTITUDE FOR RESEATING FIRE HANDLE IS 25,000 FEET.

      The autopilot may be used, if available.
    1. Airspeed ... MAINTAIN YAW DAMPER INOP SPEEDS OR 200 KCAS MINIMUM UNTIL ESTABLISHED ON A LONG STRAIGHT-IN FINAL APPROACH TO LONGEST, WIDEST RUNWAY AVAILABLE WITH MINIMUM CROSSWIND COMPONENT
    2. Lateral Hardover Protection ... DEACTIVATE LATERAL HYD S/O
    3. When ready to configure:
    4. Airspeed ... SLOW TO 175 KCAS
    5. Landing Gear ... PERFORM EMERGENCY EXTENSION
    6. NOTE: See Landing Gear Failure To Extend

    7. R ENGINE BLEED ... OFF
    8. R ENGINE PACK ... OFF
    9. CRANK MASTER ... ON
    10. START Switch ... R ENGINE
    11. NOTE: Starter will motor windmilling engine at approximately 20 to 25% HP, providing adequate steady hydraulic pressure. Starter time limits can be extended up to 10 minutes in flight.

    12. Airspeed ... FLY NORMAL NO-FLAP APPROACH SPEED
    13. GPWS/GND SPLR FLAP ORIDE ... ON
    14. GROUND SPOILERS ... OFF
    15. ANTI SKID ... OFF
    16. NOTE: A go-around has not been demonstrated in this configuration.

      After landing:
    17. Speed Brakes ... EXTEND SLOWLY (3 SECONDS MINIMUM)
    18. Use rudder and ailerons to counteract drift. In crosswinds, landing on the downwind side and veering slightly downwind prior to loss of aerodynamic control will aid in stopping on the runway. The PM shall monitor the applied brake pressure and advise the PF of overshoots in pressure. Do not apply more than 400 PSI maximum emergency braking pressure.

    Left Engine Failure and Right Hydraulic Failure

    With the left engine starter providing windmilling hydraulics, this is just like landing with Loss of Right Hydraulics Pressure or Fluid with the exception you need to turn the starter on in the last ten minutes. You just need to give the system time between actuation of hydraulic items.

    Symptoms:

    The left engine has failed but is windmilling, the synoptics show you have no hydraulic pressure or quantity on the right.

    Analysis:

    You have hydraulic pressure on the left so long as the engine is windmilling, you can keep the pressure up through the landing using the left engine starter.

    Procedures:

    [G450 AFM, §4-06-90]

      NOTE: This procedure covers loss of both Left and AUX Hydraulic Systems with a windmilling right engine. Windmilling HP rpm as low as 2.7% provides sufficient flight control power for safe flight. Flight control inputs should be minimized (20° bank angles and ±10° pitch have been demonstrated) and a “No Flap” landing performed. If the windmilling engine was shut down using the FIRE handle, it will be necessary to reseat the handle to restore hydraulic power. Prior to reseating the FIRE handle, the R FUEL S/O circuit breaker will need to be pulled in order to prevent fuel from being introduced into the engine.

      CAUTION: IF FIRE HANDLE IS RESEATED AT HIGH ALTITUDE, HYDRAULIC PRESSURE MAY NOT BE RESTORED UNTIL DESCENDING TO LOWER ALTITUDES. MAXIMUM RECOMMENDED ALTITUDE FOR RESEATING FIRE HANDLE IS 25,000 FEET.

      The autopilot may be used, if available.
    1. Airspeed ... MAINTAIN 200 KCAS MINIMUM UNTIL ESTABLISHED ON A LONG STRAIGHT-IN FINAL APPROACH TO LONGEST, WIDEST RUNWAY AVAILABLE WITH MINIMUM CROSSWIND COMPONENT
    2. Lateral Hardover Protection ... DEACTIVATE LATERAL HYD S/O
    3. When ready to configure:
    4. Flaps ... 20° (Extend using Aux Pump)
    5. Airspeed ... SLOW TO 175 KCAS
    6. Landing Gear ... PERFORM EMERGENCY EXTENSION
    7. NOTE: See Landing Gear Failure To Extend

    8. Flaps ... 39° (Extend with Aux Pump)
    9. NOTE: If the flight crew elects to land at flaps 20°, fly the approach at VREF for 20° flaps +10 knots. See AFM Section 5, Performance, for landing distance in the flaps 20° configuration.

      NOTE: If strong winds are present, add to VREF ½ of the steady state wind plus the full gust to a maximum additive of 20 knots.

    10. Ground Spoilers ... OFF
    11. L ENGINE BLEED ... OFF
    12. L ENGINE PACK ... OFF
    13. AUX Pump ... ON
    14. CRANK MASTER ... ON
    15. START Switch ... L ENGINE
    16. Airspeed ... FLY NORMAL NO-FLAP APPROACH SPEED
    17. NOTE: Nose wheel steering operation should be available with a windmilling left engine being cranked in accordance with the steps above. It is possible, however, that high demands on the left hydraulic system could decrease system performance.

      After landing:
    18. Speed Brakes ... EXTEND SLOWLY (3 SECONDS MINIMUM)
    19. NOTE: Starter will motor windmilling engine at approximately 25 to 30% HP providing adequate steady hydraulic pressure. Starter time limits can be extended up to 10 minutes in flight.

      NOTE: A go-around has not been demonstrated in this configuration.

    References

    * FSI G450 PTH, FlightSafety International Gulfstream G450 Pilot Training Handbook, Revision 6, July 2010

    * FSI G450 MTM, FlightSafety International Gulfstream G450 Maintenance Training Manual, August 2008

    * FSI G450 PTM, FlightSafety International Gulfstream G450 Pilot Training Manual, Volume 2, Aircraft Systems, October 2008

    Gulfstream GIV Operating Manual, Revision 9, October 11, 2002

    Gulfstream GIV Airplane Flight Manual, Revision 30, 11 October 2002

    Gulfstream GV Aircraft Operating Manual, GAC-AC-GV-OPS-0002, Revision 30, May 13, 2008

    Gulfstream GV Airplane Flight Manual, Revision 30, 13 May 2008

    Gulfstream GV Illustrated Parts Catalog, Revision 24, August 31, 2005

    Gulfstream GV Maintenance Manual, Revision 25, August 31, 2005

    Gulfstream GV, GV-SP, GV-SP (G550), GV-SP (G500), GIV-X, GIV-X (G450), GIV-X (G350) Master Minimum Equipment List, Revision 07, February 4, 2010.

    Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.

    Gulfstream G450 Airplane Flight Manual, Revision 36, December 5, 2013

    Gulfstream G450 Illustrated Parts Catalog, Revision 17, October 31, 2012

    Gulfstream G450 Maintenance Manual, Revision 18, Dec 12, 2013

    Gulfstream G450 Quick Reference Handbook, GAC-AC-G450-OPS-0003, Revision 34, 18 April 2013

    * Fair Use Statement

    This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in an effort to further education and advance flight safety. We believe this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit to those who have an interest in furthering flight safety.

    —Eddie's Lawyer

    My objective is to give pilots the tools they need to fly more safely. If you are a copyright holder and see your material here, that means I think your work can help to that end. Still, if you would rather your materials not appear on this website, please "Contact Eddie" using the link below and your material will be removed. It will be our loss, but I understand the need to protect creative rights.

    To answer another frequent question: yes I live in fear of law suits and have reached out for permissions where possible. Gulfstream has been very good about all of this provided I add the note shown below. Let me be clear about this: I think the world of Gulfstream Aerospace. There is no prettier wing in existence than what you see on a GV or G550 and the best cockpit I've ever touched is in my trusty G450.

    —Eddie

Revision: 20170720
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