Fuel Planning and Reserves

Components of Fuel Planning

Fuel planning for performance aeroplanes includes several key elements:

• Taxi Fuel: Fuel consumed before takeoff, including engine start and taxiing.
• Trip Fuel: The amount needed to fly from departure to destination under expected conditions.
• Contingency Fuel: Extra fuel to account for unforeseen factors such as deviations from the planned route, weather, or ATC delays. For IFR or VFR in hostile environments, this is typically 10% of trip fuel; for VFR in non-hostile environments, 5%.
• Alternate Fuel: If a destination alternate is required, this covers the route from destination to alternate, including approach and missed approach.
• Final Reserve Fuel: For jets, enough to hold for 30 minutes at 1,500 ft above the aerodrome; for props, 45 minutes at the same altitude. For VFR by day with visual navigation, 20 minutes at best range speed.
• Additional Fuel: Required by specific operation types (e.g., isolated aerodromes).
• Extra Fuel: At the captain's discretion for any further anticipated needs.

Fuel Reserve Rules Explained

The minimum fuel required is the sum of all these elements. Regulations specify the calculation methods and minimums to ensure safe completion of the flight, even if things do not go as planned. Operators base their fuel planning on aircraft manufacturer data, actual consumption monitoring, and anticipated operational conditions.

Factors Affecting Fuel Consumption

• Aircraft Weight and CG: Heavier aircraft or those with suboptimal centre of gravity positions consume more fuel and may require different speeds for maximum range.
• Performance Degradation: Age and condition of the aircraft can increase fuel burn, so performance factors or fuel biases are used in planning.
• En-Route Considerations: Drift-down, icing, and configuration deviations can all affect fuel requirements and must be factored into planning.

Practical Use

Flight planning tools, including EFBs and RTOM tables, help pilots and dispatchers calculate required fuel loads accurately, using up-to-date performance data and regulatory requirements.