Learn how to plan fuel and refuelling stops using aircraft burn, winds, reserves, usable fuel, airport services and safe leg limits.
Plan fuel and refuelling stops by calculating each leg separately with aircraft-specific cruise burn, forecast wind, taxi fuel, contingency, alternate fuel and required reserves. Add a stop whenever the leg cannot be flown with those margins inside usable-fuel and weight limits, then verify the airport’s fuel, opening hours, runway and weather.
For Aviation & Real-World Flying, every refuelling stop creates a new planning leg. Use the aircraft’s approved flight manual, pilot’s operating handbook and applicable operating rules; simulator estimates and advertised maximum-range figures are not a safe basis for an actual flight.
How do I calculate fuel for each leg?
Calculate fuel from the departure airport to the proposed fuel stop, then repeat the calculation from that stop to the next destination. A typical structure is:
required departure fuel = taxi + trip + contingency + alternate + final reserve + additional fuel
The exact components and reserve minima depend on the jurisdiction, whether the flight is VFR or IFR, and the type of operation. Our step-by-step aircraft fuel calculation explains the arithmetic, while dispatch-style trip, contingency and reserve planning covers the purpose of each fuel category.
- Establish usable fuel and loading limits. Use usable capacity rather than total tank capacity. Also calculate how much fuel can be carried without exceeding ramp, take-off or landing mass and centre-of-gravity limits.
- Build the route for that leg. Include departure, climb, cruise, descent, approach and any expected routing imposed by terrain or airspace.
- Apply forecast conditions. Convert distance into time using forecast winds and expected groundspeed. Allow for temperature, icing avoidance, weather deviations and likely delays where relevant.
- Calculate each flight phase. Use aircraft-specific performance data rather than one cruise figure for the entire leg.
- Add the required margins. Reserve fuel is protected fuel, not extra range to be consumed deliberately.
- Compare the result with allowable fuel. If the required departure fuel exceeds what the aircraft can legally and practically carry, shorten the leg.
When is a refuelling stop required?
A fuel stop is required when the planned landing fuel would fall below the applicable reserve, or when the necessary departure fuel cannot be carried within usable-capacity, mass, balance or performance limits.
There is no universal safe leg time or percentage of published range. Practical range changes with headwind, power setting, altitude, temperature, routing and payload. Plan in fuel and time, not straight-line distance alone.
- Add an earlier stop when fuel availability farther along the route is uncertain.
- Shorten the leg when a diversion would leave few suitable airports within reserve.
- Allow a wider margin when winds or weather are uncertain, rather than positioning the stop at the edge of endurance.
- Recalculate after every landing using actual remaining fuel and the latest weather; do not assume the original multi-leg plan remains valid.
How do I choose a refuelling airport?
The best fuel stop is a suitable airport with confirmed fuel and enough operational margin, not simply the airport closest to the aircraft’s theoretical range limit.
- Correct fuel: confirm the required grade, dispensing method and any aircraft compatibility restrictions.
- Availability: check operating hours, prior-permission requirements, payment arrangements and whether fuel must be requested in advance. A directory listing alone does not guarantee service.
- Runway performance: verify runway length, surface, slope, wind and expected density altitude at the planned departure weight.
- Weather and approaches: consider forecast conditions, terrain, lighting and available instrument procedures where applicable.
- Route position: avoid a long detour unless it buys a meaningful weather, runway or fuel-availability advantage.
- Fallback airport: identify another reachable fuel source in case the pump, airfield or weather becomes unavailable.
International legs may also require customs, immigration or entry arrangements. Treat those as hard constraints before selecting the stop.
How much fuel should I add at the stop?
The planned uplift is the target departure fuel for the next leg minus the verified usable fuel remaining after arrival. Do not automatically fill the tanks: full fuel can put the aircraft overweight, move its centre of gravity or reduce hot-and-high take-off performance.
| Loading choice | Use it when | Main check |
|---|---|---|
| Planned uplift only | The next leg has dependable fuel planning and normal reserves | Quantity measurement and calculation errors |
| Specified level or tabs | The aircraft documentation defines a known quantity at that level | Uneven ground and aircraft-specific limitations |
| Full tanks | The next leg is long or later fuel availability is doubtful | Mass, balance, runway and landing limits |
After refuelling, cross-check the delivered quantity against the expected uplift and indicated tank quantity. Follow the aircraft checklist for caps, vents, drains, tank selection and contamination checks. The next leg should then receive a fresh fuel calculation and, where required, its own flight plan or operational release.
What changes in a flight simulator?
The planning method stays the same, but simulator fuel predictions are only as accurate as the aircraft model and performance profile. Default planners may estimate fuel from generic data, while complex add-ons often expect loading through their own EFB, FMC or aircraft menu.
For general aviation, you can use an aircraft performance profile in Little Navmap to test candidate fuel stops. For simulated airline sectors, a SimBrief operational flight plan for MSFS can provide aircraft-specific trip fuel, alternates and reserves.
A mistake we see constantly is changing fuel through the simulator menu after loading a complex aircraft, which can leave the cockpit indications or EFB out of synchronisation. Use the aircraft developer’s intended loading method where one is provided, and check that the fuel is distributed between tanks as expected.
Common fuel-stop planning mistakes
- Using total fuel capacity instead of usable fuel.
- Planning from still-air range without applying forecast headwind.
- Counting final reserve as fuel available for the planned leg.
- Selecting a stop at maximum endurance with no margin for a diversion or missed approach.
- Assuming fuel is available because an airport has a fuel symbol.
- Filling every tank without checking take-off mass, balance and runway performance.
- Carrying the original figures into the next leg instead of recalculating from actual fuel remaining.