Fueling operations, from Eddie's aircraft.

Eddie Sez:

Refueling the G450 is very easy to do, and also very easy to do incorrectly. Make sure you know how to ground the aircraft to the fuel truck, how to do the pre-check and shutoff functional tests, and how to properly use the automatic shutoff system. The pre-check is still a bit of a mystery. My experience has been it always works when done according to the operating manual (GV, G450, and G550) and that it nevers works when done according to the placard (which agrees with the maintenance manual.) While I am still researching this, I've presented the operating manual solution.

Many of the rules we find in our aircraft manuals actually come from the National Fire Protection Association. More about this: Normal Procedures / Fueling.

Everything here is from the references shown below, with a few comments in blue.


Preparation

[G450 Aircraft Operating Manual, §09-02-10, ¶3.]

  1. Ensure aircraft and adjacent area are safe for refueling operations.

  2. Ensure fuel grade and type conforms to specifications approved for use in the Gulfstream G450. See Section 01-12-30, Engine Fuel Grades, for approved fuel grades.

  3. Ensure the fuel tank vents, located on the outboard underside of each wing, are not obstructed.

  4. Ensure aircraft and fuel carrier are properly bonded to an earth static ground.
  5. The U.S. National Fire Protection Association Standard for Aircraft Fuel Servicing (NFPA 407) has changed this requirement and Gulfstream agreed back in 2008. They just haven't gotten around to making the change in the manual. See below: Grounding Requirements.

  6. Ensure aircraft and fuel carrier are properly bonded to each other.

  7. Energize the Ground Service Bus. See Section 09-01-80, Ground Service Bus / External 60 Hz Power Application.
  8. You can refuel without it but your shutoff switches will not work and you are betting the guy in the truck is paying attention.

  9. If single point refueling (full or partial load) is to be accomplished: On the Cockpit Overhead Panel (COP), in the REMOTE FUELING section, verify the L and R SHUTOFF switches are in the off position (blue CLSD legend extinguished).

  10. If over-the-wing refueling or single point refueling (partial load) is to be accomplished: Check left wing tank and right wing tank fuel quantity (LEFT / RIGHT FUEL QTY) the Ground Service Control Panel (GSCP). The GSCP is located on the forward side of the LEER.

Grounding Requirements

Wing tip bonding point, from Eddie's aircraft.

Truck to Aircraft

Figure: Fuel truck / aircraft bonding, from Eddie's notes.

[Gulfstream Breakfast Minutes, November 14, 2008]

  • In recent years, there has been a change in philosophy and practice with regard to grounding. In the 1990 edition of the U.S. National Fire Protection Association Standard for Aircraft Fuel Servicing (NFPA 407), the requirements for Grounding were deleted and requirements for Bonding were clarified.

  • The practice in the United States has been to bond and ground, but tests have proven that if the aircraft and fuel truck are properly bonded, a grounding wire carries no electrical charge at all. This is why NFPA 407 no longer specifies grounding for safety during aircraft fueling.

  • The NFPA determination was based on the following points:
    • Grounding does not prevent sparking at the fuel surface

    • Grounding is not required per NFPA 77, Recommended Practice on Static Electricity

    • Static electrical grounding points can have high resistance, making them unsuitable for grounding

    • The wire/cable used for grounding might not be capable of conducting current in the event of an electrical fault in the ground support equipment connected to the aircraft and could become an ignition source if the wire fuses.
  • The Gulfstream Ground Handling and Servicing Handbooks, and Aircraft Maintenance Manuals have removed the grounding requirement and call only for bonding the fuel source to the aircraft during any type of fueling or defueling operation.

How Not to Ground

Photo: Improper grounding example, from Eddie's notes.

This seems to be the most popular place to ground the aircraft. The problem is there is a layer of lubricating grease between that bolt and the airplane. I put an ohm meter between this point and the aircraft and got a reading of 50,000 ohms; meaning the connection was extremely poor.

How Not to Ground, Part Deaux

Photo: Improper grounding example, from Eddie's notes.

There is clearly a rubber grommet surrounding that strap. I've seen this twice and each time the fuel truck operator seemed embarrassed when I corrected it. I put an ohm meter between this point and the aircraft and got a reading of infinity; meaning there is no connection at all, you might as well leave the cable on the truck.

How to Ground

Photo: Proper grounding example, from Eddie's notes.

We have two proper ground points on our aircraft, this one by the nose and another on the right wing. We keep a spare plug in case the truck only has the clip.

How to be prepared

Photo: External ground plug, from Eddie's notes.

Your mechanic probably has these parts tucked in the back of his tool box, a 1/4" plug with metal handle and a "Remove Before Flight" flag. Keep one of these in your door compartment and you will always be ready for the truck that only has a grounding plug with an aligator clip.


Over-the-wing Refueling

[G450 Aircraft Operating Manual, §09-02-10, ¶3.B.]

  1. Ensure preparation is completed.

  2. Remove gravity fueling filler caps from over-the-wing refueling adapters on upper outboard wings.

  3. Ground fuel nozzle(s) to aircraft at servicing area.

  4. Fuel both wings simultaneously as required. Monitor LEFT FUEL QTY and RIGHT FUEL QTY readings on GSCP until desired total fuel quantity is reached.
  5. NOTE: Since most fueling facilities are not equipped for over-the-wing refueling both wings simultaneously, it may be necessary to alternate refueling each wing incrementally. This ensures the maximum fuel imbalance of two thousand pounds (2,000 lb.) is not exceeded.

  6. When fueling has been completed, install filler caps so that FWD legend on the cap faces the forward edge of the wing. Engage cap latch and push latch flush with cap surface.

  7. Remove Ground Service Bus power. See Section 09-01-80, Ground Service Bus / External 60 Hz Power Application.

Single Point Refueling (Full Load)

[G450 Aircraft Operating Manual, §09-02-10, ¶3.C.]

  1. Ensure preparation is completed.

  2. Gain access to Single Point Refueling/Defueling (SPR) adapter through access door 192CB, located in the right wing fillet area.

  3. Remove dust cover from SPR adapter.

  4. Ground fuel nozzle to aircraft at servicing area.

  5. Connect SPR nozzle to SPR adapter.

  6. Verify left wing tank and right wing tank PRE-CHECK selector valves are in the FUEL position.

  7. Open SPR nozzle and begin refueling.
  8. NOTE: Optimum refuel servicing pressure is from 35 to 55 psig.

  9. Perform PRE-CHECK functional test (at SPR adapter) as follows:
    1. Position left wing tank and right wing tank PRE-CHECK selector valves to FLOAT. Verify refueling flow stops.

    2. Position left wing tank and right wing tank PRE-CHECK selector valves to TANK PRESS. Verify refueling flow stops.
    3. NOTE: Refueling flow may momentarily resume as selector valves pass through the FUEL selection. This condition is normal.

    4. Position left wing tank and right wing tank PRE-CHECK selector valves to FUEL. Verify refueling resumes.

    This has always worked for me, but the procedure on the placard and in the maintenance manual is different. The operating manual is basically: start fueling, both switches down, fueling stops, both switches up, fuel still stopped, both switched middle, fueling resumes. The placard has you split the switches, one up, one down. That doesn't seem to work.

  10. Perform a FUELING SHUTOFF functional test (in cockpit) as follows:
    1. Select L SHUTOFF switch to CLSD. On the GSCP, verify refueling flow to left wing tank stops.

    2. Select L SHUTOFF switch off. On the GSCP, verify refueling flow to left wing tank resumes.

    3. Select R SHUTOFF switch to CLSD. On the GSCP, verify refueling flow to right wing tank stops.

    4. Select R SHUTOFF switch off. On the GSCP, verify refueling flow to right wing tank resumes.
  11. Remove Ground Service Bus power. See Section 09-01-80, Ground Service Bus / External 60 Hz Power Application.

  12. Continue refueling until refueling flow stops.
  13. NOTE: When refueling to a full load, refueling flow stops automatically through use of the high level float valves.

  14. When refueling flow stops, cease operations and close SPR nozzle.

  15. Disconnect SPR nozzle from SPR adapter.

  16. Install dust cover on SPR adapter.

  17. Secure access door 192CB.

Single Point Refueling (Partial Load)

[G450 Aircraft Operating Manual, §09-02-10, ¶3.D.]

  1. Ensure preparation is completed.

  2. Gain access to Single Point Refueling/Defueling (SPR) adapter through access door 192CB, located in the right wing fillet area.

  3. Remove dust cover from SPR adapter.

  4. Ground fuel nozzle to aircraft at servicing area.

  5. Connect SPR nozzle to SPR adapter.

  6. Verify left wing tank and right wing tank PRE-CHECK selector valves are in the FUEL position.

  7. Configure GSCP to allow automatic refueling to desired amount as follows:
    1. Note Preselected Fuel Quantity (PRESEL) from last refueling is displayed flashing.

    2. Position Increase/Decrease (INCR/DECR) switch in appropriate direction until desired PRESEL fuel load is displayed. Note display changes from flashing to steady.

    3. Position AUTO REFUEL switch to AUTO REFUEL.

    The Classic GV ground service control panel would time out after ten minutes (or as set for individual aircraft) and whatever fuel quantity was set no longer matters. While the G450 doesn't have this problem, if somebody shuts the ground service bus off or closes all three of the controlling doors, the same thing happens. You may find yourself with more fuel than you wanted. The best technique here is to request a specific amount of fuel, even if you use the GCSP.

  8. Open SPR nozzle and begin refueling.
  9. NOTE: Optimum refuel servicing pressure is from 35 to 55 psig.

  10. Perform PRE-CHECK functional test (at SPR adapter) as follows:
    1. Position left wing tank and right wing tank PRE-CHECK selector valves to FLOAT. Verify refueling flow stops.

    2. Position left wing tank and right wing tank PRE-CHECK selector valves to TANK PRESS. Verify refueling flow stops.
    3. NOTE: Refueling flow may momentarily resume as selector valves pass through the FUEL selection. This condition is normal.

    4. Position left wing tank and right wing tank PRE-CHECK selector valves to FUEL. Verify refueling resumes.
  11. Perform a FUELING SHUTOFF functional test (in cockpit) as follows:
    1. Select L SHUTOFF switch to CLSD. On the GSCP, verify refueling flow to left wing tank stops.

    2. Select L SHUTOFF switch off. On the GSCP, verify refueling flow to left wing tank resumes.

    3. Select R SHUTOFF switch to CLSD. On the GSCP, verify refueling flow to right wing tank stops.

    4. Select R SHUTOFF switch off. On the GSCP, verify refueling flow to right wing tank resumes.
  12. On the GSCP, position the AUTO REFUEL switch to OFF. Verify the following:
    1. Refueling flow stops.

    2. ABORT is displayed in the PRESEL window.
  13. Position the AUTO REFUEL switch to TEST/RESET and then to AUTO REFUEL. Verify the following:
    1. After time-out of the TEST mode, automatic refueling resumes.

    2. The PRESEL display changes form ABORT to the preselected total fuel load desired.

    3. The LEFT and RIGHT FUEL QTY readings are increasing as fueling continues.
  14. When refueling flow stops, cease operations and close SPR nozzle.

  15. Position the AUTO REFUEL switch to OFF

  16. Remove Ground Service Bus power. See Section 09-01-80, Ground Service Bus / External 60 Hz Power Application.

  17. Continue refueling until refueling flow stops.
  18. NOTE: When refueling to a full load, refueling flow stops automatically through use of the high level float valves.

  19. When refueling flow stops, cease operations and close SPR nozzle.

  20. Disconnect SPR nozzle from SPR adapter.

  21. Install dust cover on SPR adapter.

  22. Secure access door 192CB.

References

Gulfstream Breakfast Minutes, All (ATA 28) Fuel Servicing Bonding Requirements, November 14, 2008

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