Fuel and Energy Planning for General Aviation (Part-NCO)

Every flight should end with fuel still in the tanks. For private flying in Europe the rules that make sure of it sit in Part-NCO, the part of the EU Air Operations Regulation for non-commercial operations with other-than-complex motor-powered aircraft: the club Cessna or the owner's Piper. They ask the pilot-in-command to plan enough fuel, or energy, to reach the destination, and the alternate where one is needed, and then to land with a protected final reserve.

Those rules changed on 30 October 2022. The word fuel became fuel/energy, anticipating electric and hybrid aircraft, the figures left the rule itself, and the basis of the reserve changed from cruising altitude to holding speed. Many textbooks and exam questions still carry the old wording, which is why the details matter. This article covers aeroplanes; the commercial fuel scheme is covered in fuel planning and fuel reserves and EU fuel schemes.

Part-NCO and the 2022 fuel/energy rules

Commission Implementing Regulation (EU) 2021/1296, applicable from 30 October 2022, restructured fuel planning across commercial air transport and the non-commercial and specialised operations parts. For private flights, NCO.OP.125 is now a performance-based rule: it states the outcome, enough fuel or energy for the flight and a protected final reserve, and contains no figures. The figures moved to the acceptable means of compliance, AMC1 NCO.OP.125(b), and their basis changed from minutes "at normal cruising altitude" to minutes at holding speed at 1,500 ft (450 m) above the destination or destination alternate aerodrome.

Part-NCO applies to non-commercial flights in other-than-complex aircraft; a company flying its own business jet, a complex motor-powered aircraft, works under Part-NCC instead (see EASA regulatory framework). Other Part-NCO rules changed on the same date. NCO.OP.140 received a new test for flying IFR without a destination alternate, the separate isolated aerodrome rule went (NCO.OP.105 is now blank), and NCO.OP.185 sets the in-flight fuel management duty (see Part-NCO operations).

In commercial air transport the operator's fuel policy of EU-OPS 1.255 became the fuel/energy scheme of CAT.OP.MPA.180 to .185, with named blocks of taxi, trip, contingency, alternate, final reserve, additional and extra fuel, a 5 per cent contingency in the basic scheme and a final reserve split by engine type. That structure belongs to the operator of a commercial flight. Part-NCO has none of it: the private pilot works to no approved scheme, no fixed contingency percentage and no difference between piston and turbine engines.

Pre-flight fuel planning

Planning starts with what is really in the tanks. Only usable fuel counts, and the float gauges of many light aeroplanes are inaccurate, so pilots confirm the contents visually or with a calibrated dipstick and drain a sample to check for water and the right grade (see in-flight fuel management).

The figure to carry is then built up item by item:

• taxi fuel for start, run-up and taxi, burnt before take-off and therefore not available in the air;
• trip fuel for the climb, cruise, descent, approach and landing, from the flight manual consumption at the power and mixture to be used, applied to the flight time corrected for the forecast wind;
• a contingency chosen by the pilot for stronger winds, a different routing or a missed approach;
• alternate fuel under IFR when an alternate is required;
• the final reserve fuel/energy.

A typical day VFR exam question builds the figure like this, the pilot having chosen a 5 per cent contingency:

The same logic gives the safe endurance used for decisions: an aeroplane with 136 litres usable burning 32 litres per hour has an endurance of 4 h 15 min, but only 3 h 45 min to plan with once the 30-minute reserve is protected.

Final reserve fuel/energy: VFR by day, VFR by night and IFR

The final reserve fuel/energy is the quantity that should remain in the tanks after landing. It is not a cushion for the trip; a flight planned to use it is planned to land without it. AMC1 NCO.OP.125(b) gives:

The night figure is higher because the options for a precautionary landing are far more limited in darkness. Which figure applies follows the flight actually flown, so a late departure that brings the arrival after dark brings the 45-minute reserve with it. Part-NCO draws no distinction between piston and turbine engines; the 45 and 30 minute split by engine type belongs to Part-CAT.

Because the reserve is defined as a time at holding speed, its quantity depends on the aeroplane's consumption at that speed, taken from the flight manual; exam questions usually give a single consumption figure to apply. When an IFR alternate is required, the 45 minutes are held in hand over the alternate after flying there. They are not the fuel used to fly the diversion.

View full schematic

Alternate requirements for IFR

Under NCO.OP.140 an IFR flight in an aeroplane needs a destination alternate unless the available meteorological information for the destination indicates, from 1 hour before to 1 hour after the estimated time of arrival, or from the actual time of departure to 1 hour after the ETA if that period is shorter:

• a ceiling at least 1,000 ft above the DH or MDH of an available instrument approach procedure; and
• a visibility of at least 5,000 m.

Before October 2022 the test was whether the approach and landing could be made in VMC, with a separate exemption for isolated aerodromes. Neither remains: with no alternate in reach and a forecast below that test, the flight should not be planned (see alternate aerodromes). The flight may be started or continued towards the destination when the latest information shows the destination, or at least one destination alternate, at or above its operating minima at the ETA. Part-NCO contains no take-off alternate requirement.

With an alternate required, the sequence is trip fuel, then diversion fuel, then the 45-minute reserve. An aeroplane burning 40 litres per hour on a 1 h 30 min trip with a 30-minute diversion needs 60 + 20 + 30 = 110 litres at take-off, ignoring taxi and climb. Leaving out the diversion (90 litres) or the reserve (80 litres) are the classic errors.

In-flight fuel checks and management

Fuel planning ends at engine start; fuel management goes on until shutdown. NCO.OP.185 requires the pilot to ensure that the usable fuel remaining never falls below what is needed to reach an aerodrome where a safe landing can be made with the final reserve intact. In practice that means checking the fuel at regular intervals. The useful check compares the fuel remaining with the planned figure for that point, worked out from time flown and known consumption, with the gauges as a cross-check.

When a check shows a shortfall, the plan changes. With 100 litres usable, 55 litres needed to the destination, 25 more to the alternate and a 30-litre reserve, the plan needs 110 litres and is no longer valid; while the alternate is still required, the answer is to divert early to a nearer suitable aerodrome. A diversion is planned the same way: 36 NM at a groundspeed of 90 kt takes 24 minutes, or 12 litres at 30 litres per hour, so with the 15-litre day VFR reserve at least 27 litres must be on board at the turn.

Two radio calls, set out in SERA.11012, tell ATC about a fuel problem:

Holding is where a fuel plan can quietly erode. Before entering a hold, the pilot works out how long the aeroplane can stay before it must leave for the alternate, or the nearest suitable aerodrome, with the reserve intact, and treats that time as binding. MINIMUM FUEL does not make a plan legal that would breach the reserve: if a nearer aerodrome can still be reached with the reserve intact, the right action is to go there.

Comparing with FAA Part 91 reserves

The FAA rules for private flights use similar minutes on a different basis.

Under 91.169 an FAA alternate must also be forecast at or above its alternate minimums, by default 600 ft and 2 statute miles for a precision approach and 800 ft and 2 miles for a non-precision approach. FAA rotorcraft have their own figures: 20 minutes under VFR and 30 minutes under IFR. Neither set of figures is a target: they are minimums, and a pilot's own reserve can sensibly be set higher but never lower.

Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.