Aircraft fuelling and defuelling | Safety Precautions

Aircraft fuelling and defuelling | Safety Precautions

Airside fuelling and defuelling

Aircraft refuelling operations means the overall process of loading the aviation fuel inside the aircraft. But defuelling means the process of removing fuel from aircraft and be disposed of or stored as agreed between the airline and fuel supplier operator.

Aircraft refuelling / de-fuelling operations involves many hazards. A sufficient quantity of fuel vapor may accumulate during the refuelling / de-fuelling operations from aircraft due to procedural errors, fuel leaks or when the aircraft's fuel tank is vented. A single spark of sufficient intensity is capable to ignite the fuel vapor. Fuel fire while passengers are onboard during refuelling aircraft on ground may become a disaster if not emergency response does not manage immediately and efficiently. 

In this aviation safety article, I will give you a simple idea about aircraft refuelling / de-fuelling operations, explain some terms related to it, and then list the general safety precautions that must be followed before and during performing these operations.

This article gives you general guidelines, while airport authorities, aircraft operators, and fuel suppliers have their own safety /operation manuals that are rich in aircraft refueling procedures and Personnel responsibilities regarding that. Personnel involved, including flight crew, should be careful and refer to aircraft refueling procedures in their safety manuals.

Aircraft Fuelling Safety Zone

Before writing about the Aircraft refuelling / de-fuelling safety precautionary measures, you may need to know about the Fuelling Safety Zone (FSZ) .

Fuelling Safety Zone (FSZ) is defined as an area whose boundary is at least 3 meters from the center-point of all fuel vent exits, refuelling plugs, aircraft refuelling ports, fuel hydrants, and fuel hoses and fuelling vehicles. This distance may be further increased as required by local airport authorities or civil aviation authorities.

Safety Precautions : Aircraft Fuelling

1- Aircraft  fuelling and defuelling operations must always be conducted under aircraft operator supervision, either by a flight crewmember or an aircraft technician.

2- Aircraft fuelling operation must be conducted in the open air.

3- The airport RFF service vehicles must be in its proper position .

4- Anyone not concerned with the handling of the aircraft must not be admitted into the Fuelling Safety Zone (FSZ). Exceptions can be made for escorted passengers.

5- Aircraft fuelling vehicles should be positioned so that:

  • Accessibility to aircraft by RFF [rescue and fire-fighting] vehicles are not interrupted.
  • A cleared path is maintained to permit rapid removal of fuelling vehicles from an aircraft in an emergency.
  • Fuelling vehicles do not obstruct evacuation from occupied portions of the aircraft in the event of a fire; and
  • The vehicle engines are not under the wing.

6- All ground handling equipment performing aircraft servicing functions other than fuel servicing (e.g. baggage trucks, etc.) should not be driven or be parked under aircraft wings while aircraft fuelling is in progress.

7- Open flames and lighted open flame devices must be prohibited on the apron and in other locations within 15 m of any aircraft fuelling operation. Included in the category of open flames and lighted open flame devices are the following:

  • lighted cigarettes, cigars, pipes.
  • exposed flame heaters.
  • welding or cutting torches, etc.
  • flare pots or other open flame lights.

8- Smoking is prohibited in the FSZ and on the apron, furthermore, cigarette lighters or matches should not be carried or used by anyone while engaged in aircraft fuelling operations.

9- When any part of an aircraft undercarriage is abnormally heated, the airport RFF service should be called and aircraft fuelling should not take place until the heat has dissipated.

10- Portable fire extinguishing equipment suitable for at least initial intervention in the event of fuel fire and personnel trained in its use shall be readily available, and there shall be a means of quickly summoning the rescue and firefighting service in the event of a fire or major fuel spill.

11- Stairs or boarding ramps must be in place at one of the open exits at least if personnel/passengers are still onboard the aircraft.

12- Before aircraft fuelling at night, the external power switch and the lights required for the main lighting of the cockpit and cabin must be switched on. The emergency lights must be armed. At airports with insufficient lighting, the navigation lights and any wing and ground floodlights available must also be switched on.

13- Aircraft fuelling operations are not permitted during thunderstorms.

14- Any electrical power unit connected to the aircraft must be located as far as possible from the fuelling safety zone.

15- Aircraft high-frequency (HF) transmitters must not be used during fuelling operations.

16- The use of cellular phones, laptops, cameras or anything that can be dangerously close to fuel vapor is prohibited.

17- Warning sign should be displayed and posted 15 meters from the location of operation.

18- Not wearing clothing that has a tendency to generate static electricity, such as nylonorsynthetic fabrics.

 19- Not wearing metal taps on shoes.

You may ask " Can an aircraft fuelling conducted with an engine running?"

Aircraft fuelling may have to be conducted with an engine running in exceptional cases. This is only permitted when the fuel truck is not located and connected at the same side of the aircraft as the running engine and no passengers are on board. Crew members and ground personnel directly involved in the handling of the aircraft must be informed about all fuelling operations and be able to initiate emergency procedures as soon as an emergency arises.

Safety Precautions : Aircraft Defuelling

Aircraft defuelling operations must always be conducted under operator supervision, either by a flight crewmember or an aircraft technician.

Basic safety precautions are covered in the previous paragraphs. Personnel involved, including flight crew, should be careful and refer to aircraft refueling procedures in their safety manuals.

Safety Precautions : Aircraft Refuelling With Passengers Onboard     An aircraft shall not be refueled when passengers are onboard unless it is properly staffed by qualified personnel ready to initiate and direct evacuation of the aircraft by the most practical and expeditious means available.

When an aircraft fuelling operations are conducted with passengers on board, airline Ground Personnel and Cabin Crew must:

1- Ensure that the order is given by the captain.

2- Ensure that everyone concerned with the operations is informed that passengers are on board.

3- Ensure that the RFF [rescue and fire-fighting] vehicle is present.

4- Ensure that passengers warned that aircraft refuelling will take place and that they must not:

  • smoke, operate switches , using of a PED (personal electronic device).
  • or otherwise produce sources of ignition.

5- Inform passengers to unfasten their seat belts (THE "FASTEN SEAT BELT" sign must be off)

6- Keep designated escape exits clear (An escape exit may either be a bridge to a terminal building, a cabin door or a passenger stair truck positioned on an open cabin door).

7- Ensure that all areas on the stand below designated escape exits are kept free of equipment and vehicles which would impede the deployment of an escape slide.

8- Not hamper the escape of passengers on board by ensuring that passenger stairs and bridges are clear of FOD [Foreign Object Debris ].

9- If during aircraft refuelling, the presence of fuel vapor is detected in the aircraft interior, or any other hazard arises, refuelling and all cleaning activities using electrical equipment within the aircraft should be stopped until conditions permit resumption.

10- If an APU is stopped for any reason during aircraft fuelling operations, not restart it until the flow of fuel has ceased and there is no risk of fuel vapors igniting.

Safety Precautions : Aircraft Fuelling While Passengers Embarking/Disembarking.

In addition to above Safety Precautions. Passengers route should avoid areas where fuel vapors are likely to be present and this movement should be under the supervision of a responsible person.


In this article, I highlighted the importance of applying Safety Precautions during Aircraft Fuelling such conducting it under aircraft operator supervision {either by a flight crewmember or an aircraft technician,in an open air, presence of RFF service vehicle and correct positioning etc.

In addition, Safety Precautions for aircraft defuelling, regarding his subject I recommended that personnel involved, including flight crew, should be careful and refer to aircraft refueling procedures in their safety manuals.

The article covered, safety precautions for aircraft refuelling with passengers onboard, I list some safety precautions such as ensuring that passengers warned that aircraft refuelling will take place and that they must not smoke, operate switches, unfasten their seat belts and keep designated escape exits clear..etc.

Airport authorities, aircraft operators and the fuel suppliers must provide induction and recurrent training and conduct tests to their respective personnel, whose are involved in the provision of the fuelling services regularly to ensure they understand the applicable fuel quality control & aircraft fuelling / defuelling Safety Standards. 

While coordination between airline's ground operations personnel and cabin crews must be active during aircraft fuelling / defueling operations. All must apply airline's aircraft refueling procedures and safety precautions in case any emergency arising.

Aircraft fuelling / defueling must not be conducted if the aircraft engines are running, if noticed an electrical storming, if oxygen servicing is being perform on aircraft, and when any part of the aircraft is over hot.

We hope that you have enriched your knowledge with this article, and please leave your comments below. 

We hope to see you again on our website Aviation Professional. 


Maged Saeed AL-Hadabi

I’m Instructor / Maged Saeed Al-Hadabi. ​ Air Cargo / IATA Dangerous Goods Regulations / Safety Management System Senior Instructor, Auditor [ Yemen Airways] . Approved IATA DGR/ SMS Instructor by Yemen Civil Aviation Authority. We hope you find Aviation Professional website not only informative, but interesting and helpful as well. Leave your comment , thank you.

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