GM1 CAT.OP.MPA.181 Fuel or energy scheme – fuel or energy planning and in-flight re-planning policy - aeroplanes

CAA ORS9 Decision No. 47

BASIC FUEL SCHEME

TAXI FUEL — LOCAL CONDITIONS

  1. Local conditions, as referred to in point (a) of AMC1 CAT.OP.MPA.181, include NOTAMs, meteorological conditions (e.g. winter operations), ATS procedures (e.g. LVP, collaborative decision‑making (CDM)), and any anticipated delay(s).

PLANNING OF FLIGHTS

  1. A flight should be planned by using the most accurate information available. If aircraft‑specific data that is derived from a fuel consumption monitoring system is available, this data is used in preference to data that is provided by the aircraft manufacturer. Data that is provided by the aircraft manufacturer should be used only in specific cases, e.g. when introducing a new aircraft type into service.

FUEL CONSUMPTION MONITORING SYSTEM

  1. Extensive guidance on a fuel consumption monitoring system is provided in ICAO Doc 9976 Flight Planning and Fuel Management (FPFM) Manual, Appendix 5 to Chapter 5 Example of a fuel consumption monitoring (FCM) programme (1st Edition, 2015). As a basic requirement, the fuel consumption monitoring system (commonly referred to as ‘hull‑specific fuel bias’) is a process of comparing an aeroplane’s achieved in‑flight performance to an aeroplane’s predicted performance. Variations between the achieved performance and the predicted performance result in a variation of the fuel consumption rate, which should be accounted for by the operator during flight planning and in‑flight re‑planning.

  2. The fuel consumption monitoring system is used to determine an individual aeroplane’s performance in comparison with its predicted one. In no case should data that is collected from one aeroplane be used as a basis for varying another aeroplane’s performance figures away from the predicted values.

  3. The data that is collected and used to determine an aeroplane’s actual performance should be collected in a manner acceptable to the CAA. The operator should demonstrate that the data collected during in‑service operation of the aeroplane is accurate. Where possible, the data should be collected automatically; however, manual recording of data does not preclude an operator from participating in a fuel consumption monitoring system.

ANTICIPATED MASSES — LAST-MINUTE CHANGES

  1. Where appropriate, the operating procedures should include means to revise the fuel quantity and define limits to zero fuel weight (ZFW) changes, beyond which a new operational flight plan should be calculated.

TRIP FUEL — ARRIVAL ROUTING

  1. POINT MERGE PATTERN

    When planning for a STAR to point merge, fuel for the direct STAR to the point merge should be included in the trip fuel. The fuel required to account for the probability that part of or the entire point merge route needs to be flown may be included in the contingency fuel unless there is an anticipated delay, in which case the fuel required for the route should be included in the extra fuel.

  2. POINT TROMBONE PATTERN

    When planning for a STAR or transition including a trombone pattern, fuel for the reasonably expected route should be included in the trip fuel. The fuel required to account for the probability that an extended part of or the entire trombone pattern route needs to be flown may be included in the contingency fuel unless there is an anticipated delay, in which case the fuel required for the trombone pattern route should be included in the extra fuel.

UNFORESEEN FACTORS

  1. According to its definition, contingency fuel is the amount of fuel required to compensate for unforeseen factors. Unforeseen factors are those that could have an influence on the fuel consumption to the destination aerodrome, such as deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological conditions, extended unexpected delays in flight, extended unexpected taxi times, and deviations from planned routings and/or cruising levels.

  2. For example, operators that have a fuel consumption monitoring system should calculate the trip fuel based on the individual fuel consumption. Extended unexpected delays or deviations from forecast meteorological conditions are mitigated by means of statistical data.

  3. Unforeseen factors may differ based on the type of fuel scheme adopted by each operator; the higher the capability of the operator, the fewer unforeseen factors there may be.

DESTINATION ALTERNATE AERODROME

  1. The departure aerodrome may be selected as the destination alternate aerodrome.

FINAL RESERVE FUEL

  1. The operator may determine conservative (rounded-up) FRF or energy values for each type and variant of aeroplane that is used in operations. The intent of this recommendation is:

    1. to provide a reference value for comparing to pre‑flight fuel planning computations, and for the purpose of a ‘gross error’ check; and

    2. to provide flight crews with easily referenced and recallable FRF or energy figures to support in‑flight fuel monitoring and decision‑making activities.

ANTICIPATED DELAYS

  1. In the context of fuel schemes, an anticipated delay is defined as one that can be predicted based on the information that is provided by the State of the aerodrome and/or ATS provider before the flight commences. For example, restrictions due to scheduled maintenance work on a runway are likely to cause a delay to the normal flow of inbound traffic. That delay may be promulgated either through NOTAMs or via the aeronautical information publication (AIP), including a specific time and/or date.

  2. Another example is an ATS procedure that requires an operator to fly longer routes, e.g. due to curfew during night‑time.

DISCRETIONARY FUEL

  1. Discretionary fuel is defined as ‘fuel at the sole discretion of the commander’ (PIC). The commander’s discretion over the amount of fuel to be carried is independent and cannot be encouraged or discouraged.

IN-FLIGHT RE-PLANNING

  1. In the context of fuel policy, in‑flight re‑planning means voluntarily changing the destination aerodrome, any alternate aerodrome, or the remainder of the route after the flight commences, even when the flight can be completed as originally planned. In‑flight re‑planning has a broader sense than being obliged to change the intended course of action due to safety issues (remaining fuel, failures, bad weather conditions, etc.). In‑flight re‑planning allows the operator to modify the filed flight plan after flight commencement for commercial or other reasons. However, the modified flight plan should fulfil all requirements of a new flight plan. The use of en‑route alternate (ERA) aerodromes to save fuel should comply with the in‑flight re‑planning requirements.

  2. In‑flight re‑planning should not apply when the aircraft no longer continues via the flight plan route to the intended destination for reasons that could not be anticipated. In such cases, the in‑flight fuel management policy dictates the commander’s course of action.