Fuel requirements for flights, whether under Visual Flight Rules (VFR) or Instrument Flight Rules (IFR), are outlined by the National Aviation Authority (NAA) of the aircraft’s registration country. These national regulations are based on the International Civil Aviation Organisation (ICAO) Standards and Recommended Practices (SARPs) found in Annex 6. The NAA, often called the “Regulator,” has the authority to modify ICAO SARPs to meet the specific needs of their airspace.
According to ICAO Annex 6, chapter 4, section 4.3.6.1 states that a flight cannot begin unless the aircraft has enough fuel and oil to safely complete the journey, considering the weather and any expected delays. Additionally, a reserve fuel amount is mandatory for unforeseen circumstances. For piston-engine planes, section 4.3.6.2 specifies that the fuel and oil must allow for:
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If an alternate airport is required, flying to the planned destination and then to the most critical alternate airport for 45 minutes, or flying to the alternate via a set point for the same time, ensuring it meets either 45 minutes plus 15% of the planned cruise time or two hours, whichever is less.
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If no alternate is needed, the aircraft must have enough fuel to reach the destination and then fly for 45 minutes or for 15% of the planned cruise time or two hours, whichever is less.
For turbine-engine airplanes, section 4.3.6.3 outlines similar requirements. If an alternate aerodrome is required, the aircraft must:
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Fly to the planned destination, execute an approach, and then proceed to the alternate while holding for 30 minutes at 450 m (1,500 ft) above it, ensuring sufficient fuel for potential contingencies.
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If no alternate is needed, it must have enough fuel to reach the destination and hold for 30 minutes at the same altitude or fly for two hours at normal cruise consumption.
When calculating fuel and oil, several factors must be considered, including forecasted weather, expected air traffic control delays, and any procedures for emergencies during the flight. Notably, even if plans change mid-flight, the requirements can still be met from the point of re-planning.
In-flight fuel management policies must be established by operators, as noted in Amendment 36 to Annex 6. The pilot-in-command must always ensure that usable fuel remains sufficient for a safe landing, with reserves intact. If unexpected delays arise, the pilot should communicate with air traffic control (ATC) about the fuel state. Declaring “MINIMUM FUEL” informs ATC of the need for careful handling without causing priority but indicates a potential emergency if further delays occur.
If the remaining fuel drops below the planned reserve upon landing, the pilot must declare a fuel emergency by stating “MAYDAY, MAYDAY, MAYDAY, FUEL.” This highlights the seriousness of the situation and ensures ATC is aware.
The European Union Regulation COMMISSION REGULATION (EU) No 965/2012 establishes technical and administrative procedures for air operations, including fuel policies. Operators must have a fuel policy approved by relevant authorities to ensure adequate fuel for planned flights and contingencies.
Each ICAO member country’s NAA can adjust ICAO SARPs according to their unique airspace and operational needs. Typically, national regulations will follow ICAO recommendations, potentially allowing modified or reduced fuel requirements. Operators may need special approval to use these enhanced regulations, often requiring criteria like a fuel monitoring program or specific crew training. Finally, the Regulating Authority usually specifies what must be included in the Company Operations Manual, which should detail the fuel policy and any non-standard fuel requirements.
