Brunei DCA CPL(A) Flight Planning key terms

The greatest distance an aircraft can fly through an air mass containing no wind, using a specified quantity of fuel at a chosen cruise profile. It is the baseline figure from which wind-adjusted range is calculated.

The distance flown per unit of fuel consumed, usually expressed in nautical air miles per kilogram or per pound. It peaks near the speed for maximum range and falls away at higher or lower speeds.

The maximum time an aircraft can remain airborne on a given fuel load, regardless of distance covered. It is greatest at a slower speed than maximum-range speed and is critical for holding and search work.

The rate at which an engine consumes fuel, normally quoted in kilograms or pounds per hour. It varies with power setting, altitude and temperature and drives every fuel-planning calculation.

A performance chart or data table giving true airspeed, fuel flow and power setting for a set of altitudes, weights and temperatures. Planners interpolate between the listed values to build the navigation log.

A number entered into a flight management system that trades fuel burn against time cost, setting the economic cruise speed. A low value favours fuel saving, a high value favours speed.

The position along a route beyond which it is quicker to continue to the destination than to turn back to the departure aerodrome. Wind and fuel flow on each leg determine where it lies.

A point on track from which the flight time to two nominated aerodromes is identical, allowing for wind on both headings. It is used to plan the critical fuel case for a diversion.

The vector relationship between true heading and true airspeed, wind direction and speed, and the resulting true track and groundspeed. Solving it gives the heading to steer and the time for each leg.

The speed of the aircraft over the earth's surface, obtained by combining true airspeed with the along-track wind component. It converts leg distance into leg time on the navigation log.

The angular difference between the true heading flown and the true track made good, caused by the crosswind component. It is applied to track to obtain the heading to steer.

The speed of the aircraft through the air mass, correcting indicated airspeed for position error, instrument error, compressibility and air density. It is the input to the wind triangle and cruise tables.

A worksheet recording each leg's waypoint, track, wind, heading, airspeed, groundspeed, distance, time and fuel. It is the working document from which the operational flight plan fuel figures are checked in flight.

The in-flight record of fuel on board at each checkpoint compared with the planned figures. Persistent negative trends prompt a recheck of consumption, altitude or routing before reserves become threatened.

Fuel carried in addition to trip fuel to cover contingency, alternate, final reserve and any extra requirements. It must remain untouched except in circumstances the operator's manual defines as permissible.

Fuel added to trip fuel to cover unforeseen factors such as route deviation, wind stronger than forecast or altitude change. Its size follows a percentage rule or a statistical method approved by the authority.

The minimum fuel that must remain on landing at the destination or alternate, expressed as time at holding speed at a stated altitude. Landing below it requires a report to the authority.

Fuel needed to fly from the destination, or from the point where a diversion is decided, to the nominated alternate aerodrome. It includes an approach and landing allowance at the alternate.

Fuel required from take-off to touchdown at the destination, covering taxi-out, climb, cruise, descent and approach. It is the largest planned component and is adjusted for forecast wind and temperature.

Fuel planned for a diversion from a point in flight to an alternate, including climb, cruise, descent and approach. It is calculated at the diversion weight and forecast conditions at the time of the decision.

The worst combination of depressurisation, engine failure, icing and headwind that the aircraft must be able to survive on the planned fuel. It is checked for the equal time point on long over-water routes.

Fuel set aside for a expected delay at the destination, burned at holding speed and low altitude where flow is high. It is often part of contingency and is tracked separately from final reserve.

The length of the take-off run available plus any clearway declared for the runway. It limits the distance in which the aircraft must reach screen height after an engine failure.

The length of the take-off run available plus any stopway declared. It must equal or exceed the distance needed to accelerate to decision speed and then stop on a rejected take-off.

The runway length at which the distance to continue after an engine failure at V1 equals the distance to stop. It gives the lowest possible V1 for the available runway and weights.

The decision speed at which, following an engine failure, the take-off can still be safely continued or rejected within the runway. It is derived from runway length, weight, slope and conditions.

The reported state of the runway surface, such as dry, wet, contaminated with snow or standing water, and its braking action. It increases stopping distance and reduces permitted take-off and landing weights.

The distance needed from crossing the threshold at screen height to coming to a complete stop. It is compared with the landing distance available, with a safety factor applied to the actual figure.

The length of runway declared suitable and available for a landing rollout from the threshold. It may be shortened by displaced thresholds or temporary work and must cover the required landing distance.

A threshold moved down the runway from the physical end, usually because of obstacles or work in the first portion. The paved area before it may be used for take-off but not for landing touchdown.

The four published figures for a runway: take-off run available, take-off distance available, accelerate-stop distance available and landing distance available. They define the legal limits used in performance calculations.

A document listing the mass of each load item, its arm from the datum and the resulting moment, giving total mass and centre of gravity. It must be signed before flight and remain within the envelope.

The certified forward and aft limits of centre of gravity plotted against mass for a given aircraft. Operating outside it degrades stability, control and performance and is not permitted.

The mass of the aircraft and its contents excluding usable fuel. It is the starting point for the mass and balance calculation and must not exceed its certified maximum.

A fixed reference point or plane from which all arms are measured in the mass and balance calculation. Its position is defined in the aircraft documentation and does not change.

The altimeter setting that, when set on the subscale, makes the altimeter read elevation above mean sea level at the aerodrome. It is used below the transition altitude and for terrain clearance planning.

The standard altimeter setting of 1013.2 hectopascals, used above the transition altitude so that all aircraft share a common pressure datum. Altitudes shown are then flight levels, not heights above sea level.

The altitude at or below which the altimeter is set to the local QNH and above which it is set to standard pressure. It is published for each aerodrome and marks the change between altitudes and flight levels.

An altitude expressed in hundreds of feet above the standard pressure datum of 1013.2 hectopascals. It is used for cruising above the transition altitude and for separation between aircraft.

The vertical margin between the aircraft's planned path and the highest obstacle or terrain along the route. It is checked using charted minimum altitudes, corrected for temperature and pressure error.

The lowest altitude that provides a stated margin over terrain and obstacles within a defined area or route segment. Charts publish it so planners can build a safe profile for each leg.

A published altitude providing obstacle clearance within each grid square of an area chart, used when off established routes. It is a planning aid and does not guarantee radio or navigation coverage.

A map showing navigation aids, airspace, routes, obstacles and terrain for a defined area, drawn to a stated scale and projection. Each type, such as enroute or approach, serves a particular planning or flying purpose.

The Aeronautical Information Publication, the state's official document containing permanent aeronautical information such as aerodromes, airspace, procedures and services. It is amended regularly and is the primary planning reference.

A notice distributed by means of telecommunication containing information on the establishment, condition or change of any facility, service or procedure important to flight. It covers temporary matters that cannot wait for the next AIP amendment.

A common effective date, normally every 28 days, on which aeronautical information changes are introduced worldwide. Planners must confirm which cycle an AIP amendment or chart edition belongs to.

A method of navigation allowing an aircraft to fly any desired path within the coverage of navigation aids or within the capability of self-contained equipment. It removes the need to overfly ground stations.

A statement of the navigation accuracy, in nautical miles, that must be maintained for 95 percent of the flight time within a defined airspace. It also implies on-board performance monitoring and alerting.

A specified geographical location, defined by coordinates or by reference to a navigation aid, used to define a route or flight path. Waypoints are named and coded in navigation databases.

Airborne equipment that stores a navigation database, computes the flight path and provides guidance, performance and fuel predictions. Its predictions underpin the operational flight plan and in-flight monitoring.

The set of waypoints, airways, procedures and navigation aids loaded into the flight management system. It must be current for the AIRAC cycle and checked against the planned route before departure.

The document prepared by the operator for a specific flight, giving route, altitudes, fuel figures, masses and alternates. It is signed by the pilot in command and amended if conditions change before departure.

The information on a flight submitted to air traffic services so that they can provide alerting and control. It states aircraft identification, route, levels, times and endurance and must be updated when it changes.

The process of revising route, level, speed or destination after departure because of weather, fuel or technical factors. It requires a new fuel and time calculation and, where relevant, a revised ATS flight plan.

A structured sequence, such as identifying the problem, gathering information, weighing options, acting and reviewing, used to reach a defensible choice under time pressure. It guards against fixation and premature commitment.

The tendency to keep following an original plan despite mounting evidence that it is no longer safe or sensible. Recognising it early supports a timely diversion or return rather than continued descent into a worsening situation.

A framework in which crews anticipate external threats, trap errors before they affect the flight and manage any that remain. It is applied to planning by briefing likely threats such as weather, terrain and fuel shortfalls.