Risks of Aircraft Refueling and Defuelling

by Admin on November 2, 2022

One of our core services is aviation defuelling or refueling. As the fuel provider of choice for a diverse range of operators, iJET maintain an extensive portfolio of suppliers.

Aircraft refueling and defuelling are associated with hazards which must be mitigated to acceptable levels. Fuel hydrant systems and tanker/bowser systems are subject to the same issues. For multicrew transports and business jets, pressure refuelling is the norm, but gravity refueling is an option as a backup. However, there are still potentially hazardous conditions associated with kerosene fuel used in turbine engine aircraft compared with aviation gasoline used in piston engine aircraft.

Fuel vapour can be unintentionally ignited by a single spark, posing a major risk. Insufficient fuel vapour may result from spills caused by procedural errors, leaks, aircraft tank venting, or failure of pressurized fuel lines or their couplings to create a high risk of ignition. When fuel is moved inside the aircraft tank during fuelling process or accumulates on the surface of vehicles or aircraft, electrostatic energy can be discharged, resulting in a spark that can ignite fuel vapour.

The Fuel Management System

The goal of Fuel Management is to ensure that fuel-related flight risks are mitigated in accordance with a number of regulations, policies, processes, and procedures. Depending on the rules of flight, alternative aerodrome requirements, and special areas of operation such as ETOPS or remote destinations, regulations will mandate the minimum amount of fuel required for commercial air transportation. Compliance with regulatory requirements should be strengthened where appropriate by Company policies and procedures to ensure sufficient fuel is identified and loaded on the aircraft before the flight. Further guidelines should be provided to the flight crew regarding appropriate fuel use and monitoring during ground operations, during flight, and in the event of a diversion, regardless of the operating conditions.

Insufficient Fuel

Inadequate or incomplete preflight fueling aircraft plan can result in the calculation of a total fuel requirement which is not actually sufficient for the planned flight.

Excessive Fuel

Inadequate or incomplete preflight fuel planning or non-compliance with Company policy or manufacturer limitations can result in the calculation of a total fuel figure well in excess of that actually required for the intended flight.

Fuel Shortages

It is possible to calculate a total fuel requirement for an upcoming flight that is not actually sufficient due to inadequate or incomplete preflight fuel planning.

Fuel Excess

The calculation of a total fuel figure well in excess of what is actually required for the intended flight is often caused by a lack of or inadequate preflight fuel planning or noncompliance with Company policies or manufacturer limitations.

Refuelling Effects

There are many potential effects of an insufficient supply of fuel. They include:

  • If fuel falls below minimum brake release fuel prior to departure, the plane must return to the gate at origin.
  • Insufficient fuel causes an aircraft to turn back.
  • Insufficient fuel forced enroute diversion.
  • Insufficient fuel on approach caused the pilot to break IFR limits.
  • Fuel depletion requires the declaration of an emergency situation (PAN or MAYDAY).
  • In the event of non-compliance with fuel requirements, regulatory enforcement action may be taken against the Company and/or its crew.
  • A fuel starvation caused the engine to fail.

Overuse of Fuel May Result In the Following Effects:

  • Excessive weight when taking off or landing an aircraft.
  • Fuel burn increased due to the extra weight in fuel being carried.

Aircraft Refueling Procedures and Safety Precautions

Ground handlers or aircraft refueller must refer to the necessary procedure documents since this is a special and infrequent operation. A dedicated de-fueling tanker/bowler must be used to offload the fuel removed from aircraft tanks.

Refueling Aircraft with PEDs

During safe aircraft refuelling, there is a small risk that a PED may generate or induce a spark strong enough to ignite fuel vapour released, but this is extremely unlikely. Especially concerning is the proliferation of mobile phone batteries that fail dangerously below specifications. A fuel/air mixture may ignite if such a failure is of sufficient magnitude, but it is not currently known. Under certain circumstances, such an event may occur during refueling, so it is recommended that such circumstances be carefully considered and mitigated.

Modern aircraft may also be affected by PEDs onboard or in close proximity to fuel gauges and navigation equipment, causing false fire warnings in cargo and baggage compartments. PEDs are recommended to be prohibited on the apron area near refueling operations by airport operators. PEDs should be discouraged from being used by passengers boarding or disembarking aircraft without using an airbridge.



The Process of Refueling with Passengers on Board

Refuelling procedures, including emergency evacuation procedures, should be outlined in both the Operations Manual and Cabin Crew Manual by aircraft operators. There should be clear definitions of crew stations and duties, as well as appropriate communication with passengers. When selecting exits to be used for Emergency Passenger Evacuations, procedures should consider whether or not airbridge access and ground steps are available. The flight deck should normally be manned by at least one member of the flight crew.

When refueling begins after gate arrival, but before all inbound passengers have even disembarked – or are in the process of disembarking – this situation is often overlooked. If doors have not been opened and disembarkation has not started, an unexpected evacuation requirement might cause difficulties if the crew is busy with routine procedures after shutdown.

Safety Precautions

ICAO SARPs can be adjusted by each national aviation authority in accordance with the characteristics of its sovereign airspace and the needs of its operators. To formulate their basic national fuel regulations, the National Authorities in most cases follow the ICAO fuel recommendations. In such a case, the Authority may modify, reduce or enhance fuel requirements according to its regulations.

There are various types of regulations, including No Alternate IFR flight requirements, reduced or even zero contingency fuel requirements and regulations on the use and amount of final reserve fuel. To conduct flights using the enhanced regulations, the Operator will be required to apply for special approval from the Regulator, and will normally need to meet specified criteria in order to qualify.

Fuel monitoring, flight crew training, and/or a specific level of flight following capability may be included in these criteria. Company Operations Manuals are normally prescribed by the Regulating Authority. Within the Company Operations Manual, the required content will certainly include a description of the Company’s fuel policy, as well as any specific regulatory approvals for nonstandard fuel requirements.

Aviation Fuelling Support by iJET

Our Fuel Service team is available 24 hours a day, 7 days a week, to help you with any questions regarding aviation fuel types, availability, or pricing.

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