Determination of the Quantities of Fuel and Oil Carried

Determination of the Quantities of Fuel and Oil Carried

Adequate fuel quantity (block fuel) to cover the requirements of Trip, Contingency, Alternate, Reserve and Taxi must be loaded prior to departure.

An Operational Flight Plan (OFP) = Computerized Flight Plan (CFP) is used to calculate fuel required for the flight using the Company fuel policy at the planning stage taking into account:

• Anticipated meteorological conditions;
• Weights;
• Routings;
• Delays;
• ATS procedures;
• Any procedures or limitations contained in the Operations Manual;
• Minimum cost operation;
• Realistic aircraft fuel consumption data based on data provided by the aircraft manufacturer. For this purpose a fuel performance factor shall be determined for each aircraft – refer to OM Part B.

The OFP will include an amount of recommended extra fuel where experience on a route has shown that flight level restrictions or destination holdings are common.

When weather or other factors dictate the use of an alternate which is not listed in the OFP, the Commander must request another OFP with the alternate used.

At any time during a flight the fuel quantity remaining on board must be enough to deal with the planned operation and the possible deviations.

The final authority and responsibility for fuel loads and the fuel management in flight rests with the Commander.

Standard Fuel Calculation Procedure

The minimum fuel for a sector is the sum of:
1) Taxi Fuel;
2) Trip Fuel;
3) Contingency Fuel (Route Reserve);
4) Alternate Fuel (if required according to OM Part A);
5) Final Fuel;
6) Additional Fuel (if required); and
7) Extra Fuel (if economically and/or operationally justified).

Taxi Fuel

The fuel expected to be used prior to take-off, including engine start, taxi and APU consumption. To define amount of taxi fuel a statistical average taxi time at various departing stations should be used. If statistical data are not available a minimum of 10 minutes taxi time shall be applied for calculation.

Maximum ramp weight may not be exceeded with taxi fuel on board.

Trip Fuel

Trip Fuel shall be sufficient for:

• Fuel for take-off and climb from aerodrome elevation to initial cruising level/altitude, taking into account the expected departure routing; and
• Fuel from top of climb to top of descent, including any step expected climb/descent, using predefined cursing speed strategy (e.g. cost index, fixed mach number, etc.); and
• Fuel from top of descent to the point where the approach is initiated, taking into account the expected arrival procedure; and
• Fuel for approach and landing at the destination aerodrome.

Contingency Fuel

The purpose of Contingency fuel (route reserve fuel) is to compensate for any unforeseeable factors, such as:

• Deviation from forecast meteorological conditions; or
• Deviation from planned routings and/or cruising levels/altitudes.

Contingency fuel shall be the higher of a) or b) below:
a) Either one of the following:

• 5% of the planned Trip Fuel of the flight or, in the event of in-flight replanning, 5% of the trip fuel for the remainder of the flight; or
• Not less than 3% of the planned Trip Fuel of the flight or, in the event of inflight replanning, 3% of the trip fuel for the remainder of the flight, provided that an en-route alternate is available. The en-route alternate shall be located within a circle having a radius equal to 20% of the total flight plan distance, the centre of which lies on the planned route at a distance from the destination of 25% of the total flight plan distance, or at least 20% of the total flight plan distance plus 50 NM, whichever is greater; or
• An amount of fuel sufficient for 20 minutes flying time based upon the planned trip fuel consumption provided that a fuel consumption monitoring programme for individual aeroplanes is used; or
• An amount of fuel based on a statistical method approved by the Authority which ensures an appropriate statistical coverage of the deviation from the planned to the actual trip fuel. This method shall be used to monitor the fuel consumption on each city pair/aeroplane combination and used for a statistical analysis to calculate contingency fuel for that city pair/aeroplane combination.

b) An amount to fly for 5 minutes at holding speed at 1500 ft above the destination aerodrome in ISA conditions.

Alternate Fuel

Alternate Fuel shall be sufficient for:
1) Missed approach from the applicable minima at the destination aerodrome to missed approach altitude, taking into account the complete missed approach procedure; and
2) Climb from missed approach altitude to cruising level/altitude, taking into account the expected routing; and
3) Cruise from top of climb to top of descent at LRC speed, on the expected routing; and
4) Descent from top of descent to the point where the approach is initiated, taking into account the expected arrival procedure; and
5) Executing an approach and landing at the destination alternate aerodrome.

If two destination alternates are required, Alternate Fuel shall be sufficient to proceed to the alternate which requires the greater amount of Alternate Fuel.

If Alternate Fuel is not required it shall be substituted at least by Additional Fuel.

Final Fuel

Final Fuel shall be sufficient for 30 minutes at holding speed at 1500 ft above alternate aerodrome elevation (or destination aerodrome when no alternate is required) in ISA conditions, calculated with estimated weight on arrival at the alternate or the destination (when no alternate is required).

Additional Fuel

Additional fuel may include effect of any CDL and/or MEL item if no adjustment has been made to the fuel calculations. Any ballast fuel carried shall not be included in endurance calculation.

On top of that additional fuel shall be sufficient for:

• 15 minutes of flight at holding speed at 1500 ft above the destination aerodrome in ISA conditions when the flight is operated without a destination alternate; and/or
• To allow for the possible failure of a power plant or loss of pressurisation, based on the assumption that such a failure occurs at the most critical point along the route, for the aeroplane to:

- Descend as necessary and proceed to an adequate aerodrome; and
- Hold there for 15 minutes at 1500 ft above the aerodrome elevation in ISA conditions; and
- Make an approach and landing.

This additional fuel is only required if the minimum amount of fuel calculated in accordance with standard procedure does not cater for such an event.

Extra Fuel

Extra fuel may be uplifted at the discretion of the Commander for operational reasons.

However it should be remembered that carrying too much unnecessary extra fuel increases the fuel consumption for that sector and therefore reduces the economy of the operation (lower flex temperature, more tire and brake wear, more time in climb phase, lower optimum flight level etc.).

Decision Point Fuel Calculation Procedure

When planning to a destination aerodrome via an en-route decision point the fuel required is the greater of a) or b) below:
a) The sum of:

• Taxi fuel;
• Trip fuel to the destination aerodrome, via the decision point;
• Contingency fuel of not less than 5% of the estimated fuel used from the decision point to the destination aerodrome;
• Alternate fuel if a destination alternate is required or additional fuel (15 min holding 1500 ft above destination aerodrome) if destination alternate is not required;
• Final reserve fuel.

b) The sum of:

• Taxi fuel;
• Trip fuel to a suitable en-route alternate via the decision point;
• Contingency fuel of not less than 3% of the estimated trip fuel from the departure aerodrome to the en-route alternate;
• Final reserve fuel.

Isolated Destination Fuel Calculation Procedure

Destination aerodrome is considered to be isolated if the distance to its closest alternate is such, that it would require reserve fuel (alternate + final reserve) in excess of fuel required to hold for 2 hours (based on estimated landing weight). Thus, when planning to an isolated aerodrome, fuel required is the sum of:
1) Taxi fuel;
2) Trip fuel;
3) Contingency fuel;
4) Fuel required to hold for 2 hours, calculated for optimum holding consumption at a weight estimated for landing.

Tankering

Commanders shall base decision for or against economical tankage on fuel index concept and recommendations and/or limitations stated below.

Tankering is not recommended when:

• Maximum take-off weight is restricted by RWY length;
• Performing take-off in very hot and/or high environment;
• Landing RWY is expected to be wet;
• Next rotation of an applicable aeroplane is not known.

Tankering is not authorised when:

• It would impose exceeding of take-off or landing performance limits;
• Take-off RWY is contaminated;
• Landing RWY is expected to be contaminated;
• Maximum take-off weight is restricted by aeroplane technical status (MEL item);
• It may cause significant delay;
• It would impose payload reduction.

Final decision to perform tankering is always under Commander’s discretion.

Oil

The minimum oil quantity requested for any flight is equal to the minimum quantity specified for a particular engine, plus the estimated oil consumption. Adequate oil quantity to cover the requirements of trip, contingency, alternate, reserve and taxi must be loaded prior to departure.

Minimum and maximum oil quantities and maximum average estimated oil consumption (if no data from maintenance available) are indicated in the applicable OM Part B.

Consumption Records of Fuel and Oil

Fuel records will be retained with the OFP, Journey Log and Aircraft Technical Log. Oil carriage and consumption will be recorded in the Aircraft Technical Log.