The procedures specified in this Schedule are concerned with the monitoring of fuel use by aeroplane operators. The methods proposed are representative of the most accurate established practices.

Any equivalent procedures to those contained in this Schedule must only be allowed after prior application to and approval by the Regulator for the aeroplane operator concerned.

The aeroplane operator performing on an ad-hoc basis flights attributed to another aeroplane operator must provide to the latter the fuel measurement values according to the Block-off/Block-on method.

Where no fuel uplift for the flight or subsequent flight takes place, the amount of fuel contained in aeroplane tanks (T_N or T_N+1) must be determined at block-off for the flight or subsequent flight. In exceptional cases the variable T_N+1 cannot be determined. This is the case when an aeroplane performs activities other than a flight, including undergoing major maintenance involving the emptying of the tanks, after the flight to be monitored. In such case the aeroplane operator may substitute the quantity “T_N+1 + U_N+1” with the amount of fuel remaining in tanks at the start of the subsequent activity of the aeroplane or fuel in tanks at Block-on, as recorded by technical logs.

The aeroplane operator performing on an ad-hoc basis flights attributed to another aeroplane operator must provide to the latter the fuel measurement values according to the Block-off/Block-on method.

Where an aeroplane does not perform a flight previous to the flight for which fuel consumption is being monitored (e.g., if the flight follows a major revision or maintenance), the aeroplane operator may substitute the quantity R_N-1 with the amount of fuel remaining in the aeroplane’s tanks at the end of the previous activity of the aeroplane, as recorded by technical logs.

For flight(s) without a fuel uplift (i.e. flight _N+1, …, flight _N+n), the aeroplane operator must use the following formula to allocate fuel use from the prior fuel uplift (i.e. from flight _N) proportionally to block hour—

$$F_N=U_N\ast \left[\frac{B{H}_N}{B{H}_N\pm B{H}_{N\pm 1}\pm \cdot \cdot \cdot \pm B{H}_{N\pm n}}\right]$$

$$F_{N\pm 1}=U_N\ast \left[\frac{B{H}_{N\pm 1}}{B{H}_N\pm B{H}_{N\pm 1}\pm \cdot \cdot \cdot \pm B{H}_{N\pm n}}\right]$$

$$F_{N\pm n}=U_N\ast \left[\frac{B{H}_{N\pm n}}{B{H}_N\pm B{H}_{N\pm 1}\pm \cdot \cdot \cdot \pm B{H}_{N\pm n}}\right]$$

where—

• F_N = Fuel used for the flight under consideration (i.e. flight _N) determined using fuel uplift (in tonnes);

• F_N+1 = Fuel used for the subsequent flight (i.e. flight _N+1) determined using fuel uplift (in tonnes);

• F_N+n = Fuel used for the follow-on flight (i.e. flight _N+n) determined using fuel uplift (in tonnes);

• U_N = Fuel uplift for the flight under consideration (i.e. flight _N) (in tonnes)59;

• BH_N = Block hour for the flight under consideration (i.e. flight _N) (in hours);

• BH_N+1 = Block hour for the subsequent flight (i.e. flight _N+1) (in hours); and

• BH_N+n = Block hour for the follow-on flight (i.e. flight _N+n) (in hours).

For fuel allocation with block hour, the following calculation methods apply.