GM1 CAT.OP.MPA.181 Selection of aerodromes and operating sites  — helicopters

CAA ORS9 Decision No. 47

Text in magenta in force from 30 October 2025

LANDING FORECAST

(a) Meteorological data have been specified that conform to the standards contained in the Regional Air Navigation Plan and ICAO Annex 3. As the following meteorological data are point- specific, caution should be exercised when associating it with nearby aerodromes (or helidecks).

(b) Meteorological reports (METARs)

    (1) Routine and special meteorological observations at offshore installations should be made during periods and at a frequency agreed between the meteorological authority and the operator concerned. They should comply with the provisions contained in the meteorological section of the ICAO Regional Air Navigation Plan, and should conform to the standards and recommended practices, including the desirable accuracy of observations, promulgated in ICAO Annex 3.

    (2) Routine and selected special reports are exchanged between meteorological offices in the METAR or SPECI (aviation selected special weather report) code forms prescribed by the World Meteorological Organisation.

(c) Aerodrome forecasts (TAFs)

    (1) The aerodrome forecast consists of a concise statement of the mean or average meteorological conditions expected at an aerodrome or aerodrome during a specified period of validity, which is normally not less than 9 hours, or more than 24 hours in duration. The forecast includes surface wind, visibility, weather and cloud, and expected changes of one or more of these elements during the period. Additional elements may be included as agreed between the meteorological authority and the operators concerned. Where these forecasts relate to offshore installations, barometric pressure and temperature should be included to facilitate the planning of helicopter landing and take-off performance.

    (2) Aerodrome forecasts are most commonly exchanged in the TAF code form, and the detailed description of an aerodrome forecast is promulgated in the ICAO Regional Air Navigation Plan and also in ICAO Annex 3, together with the operationally desirable accuracy elements. In particular, the observed cloud height should remain within ±30 % of the forecast value in 70 % of cases, and the observed visibility should remain within ±30 % of the forecast value in 80 % of cases.

(d) Landing forecasts (TRENDS)

    (1) The landing forecast consists of a concise statement of the mean or average meteorological conditions expected at an aerodrome or aerodrome during the two-hour period immediately following the time of issue. It contains surface wind, visibility, significant weather and cloud elements and other significant information, such as barometric pressure and temperature, as may be agreed between the meteorological authority and the operators concerned.

    (2) The detailed description of the landing forecast is promulgated in the ICAO Regional Air Navigation Plan and also in ICAO Annex 3, together with the operationally desirable accuracy of the forecast elements. In particular, the value of the observed cloud height and visibility elements should remain within ±30 % of the forecast values in 90 % of the cases.

    (3) Landing forecasts most commonly take the form of routine or special selected meteorological reports in the METAR code, to which either the code words ‘NOSIG’, i.e. no significant change expected; ‘BECMG’ (becoming), or ‘TEMPO’ (temporarily), followed by the expected change, are added. The 2-hour period of validity commences at the time of the meteorological report.

The title and text below will replace the title and text above on 30 October 2025:

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

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.