Safe aircraft refueling operations require strict adherence to procedures and careful application of the safety precautions, not solely by the refueling operators but also flight crew, the cabin crew, and the other ground operators.
This article highlights the safety precautions that must be considered when refueling an aircraft. It also describes supplementary tasks that are necessary if refueling when passengers are on-board.
The main threat throughout the refueling operation is the fire threat. The general safety precautions for refueling/defueling are available in:
- A220 AMP servicing – REPLENISHING AND DEPLETING – FUEL REPLENISHING AND DEPLETING.
- A300/A310 AMM servicing – REPLENISHING OF FUEL TANKS.
- A320/A330/A340 AMM servicing – FUEL – fuel system – servicing – General Refuel/Defuel Safety Procedures.
- A380 AMM FUEL – REFUEL/DEFUEL SYSTEM – servicing – General Refuel/Defuel Safety Procedures.
- A350 MP FUEL – DISTRIBUTION – REFUEL/DEFUEL SYSTEM – MAINTENANCE PROCEDURES – General Refuel/Defuel Safety Procedures.
In addition to the availability of the firefighting equipment and the use of personal protection by the fuelling operator, bonding the craft and respecting fuelling safety zones is crucial.
BONDING AND GROUNDING THROUGHOUT REFUELING/DEFUELING
Bonding ensures electrical continuity between the aircraft and the refueling vehicle, preventing any spark to appear once the ground operator connects the refueling hose to the aircraft coupling.
It is mandatory to bond the aircraft to the refueling vehicle/device before connecting the refueling hose
One of the aircraft grounding (earthing) points must be used to connect the bonding cable. depending on the aircraft type, the grounding (earthing) points will be located:
- On the nose landing gear (NLG).
- On the main Landing Gears (MLG).
- On the wings.
- On the engine air inlet.
- At the high pressure (HP) connector.
Grounding (earthing) points are indicated by a placard to ease their identification. the type of placard could differ depending on its location and the aircraft type.
A cable section of twenty mm² or more is usually recommended to ensure sufficient bonding. the total electrical resistance of the cable between the A/C and the fuel tanker must not be more than ten ohms.
2- GROUNDING OR EARTHING
Grounding ensures electrical continuity between the aircraft and the earth. static electricity resulting from the flight or the environmental conditions on the ground (wind with dust, sand, etc…) is discharged to the earth through the tires.
Airbus doesn’t request the grounding (earthing) of the aircraft or of the refueling vehicle throughout refueling operations however some local authority regulations may request it.
3- REFUELLING SAFETY ZONES
As an industry standard, a 3-meter safety zone must be respected around the area located under the NACA vents, overpressure protectors, and refuel coupling(s). These areas must be clear of any object or personnel.
Their location can be found in the Refuel/Defuel Safety procedures of the AMM/AMP/MP. additionally, an escape corridor must be clear of obstacles so the refueling vehicle can leave the area in case of an emergency.
3- REFUELLING WITH PASSENGERS ON-BOARD
Today’s short transit time used by some operators usually requires refueling operations while passengers are still -or already- on board the aircraft.
It is essential for all actors to respect further safety precautions and be ready to initiate an emergency evacuation should it be needed.
KEEP GROUND AREAS CLEAR FOR SLIDE DEPLOYMENT
Depending on the ground servicing and catering operations, the area beneath the available exits must be clear to enable proper slide deployment in the case of an evacuation.
4- CABIN & PASSENGERS HANDLING
The flight crew must turn off the seat belt signs and switch on the NO SMOKING signs (if installed) and inform the cabin crew when the refueling/defueling operation starts and ends.
The CCOM SOP “Refuelling/defuelling – Refuelling/defuelling with passengers onboard” provides the procedure and precaution to apply.
The cabin aisle(s) and exits must be free of obstacles that could impair the evacuation path. Cabin curtains should be secured in the open position and the cabin lighting ought to be on.
The cabin crew must inform passengers that a refueling operation is ongoing and that they must not fasten their seatbelts to ease evacuation in the case of an Associate in Nursing emergency.
Each cabin crew ought to be ready for evacuation and a minimum of one cabin crew member should be positioned at each door pair.
For all refueling operations, the safety of ground personnel, flight crew, cabin crew, and any passengers aboard the aircraft is paramount. it’s why the prevention of any unsafe conditions requires the refueling vehicle or equipment to be bonded to the aircraft, preventing arcing or sparks.
an exclusion area of three meters from the aircraft’s vent tanks, overpressure protection or refuel coupling, and equipment ought to be maintained during refueling. the appropriate PPE ought to be worn by the operator and fire fighting equipment available with a defined escape corridor in the event of a fire.