Accelerate-go distance required
Distance needed to accelerate to decision speed, experience an engine failure and continue take-off to 35 ft above runway.
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Flight Planning
Browse Flight Planning terms for pilots, air traffic controllers, cabin crew and aviation learners.
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Approach Climb Requirement
The minimum climb gradient that an aircraft must meet during the missed approach phase, considering one engine inoperative.
View termapproach reference speed
Speed selected for use on final approach segment, ensuring safe control margin above stall but stable profile.
View termBalanced field length
Runway length at which accelerate-go and accelerate-stop distances are equal under specified conditions.
View termbasic operating weight
The weight of an aircraft including crew, unusable fuel, and all necessary fluids for operation, excluding payload and usable fuel.
View termcalibrated airspeed
Indicated airspeed corrected for instrument and position errors, used for accurate performance calculations.
View termclearway length
A defined rectangular area beyond the runway, free of obstructions, suitable for aircraft to continue take-off in case of engine failure.
View termdecision altitude
Specified altitude in precision approach at which a missed approach must be initiated if runway not in sight.
View termdecision distance available
Distance from threshold to point on runway where go‑around decision altitude is reached, allowing a missed‑approach before runway end.
View termdensity altitude
Altitude at which the aircraft feels it is flying based on current pressure, temperature, and humidity, affecting performance.
View termen‑route alternate fuel
Fuel required to fly from the destination to an alternate aerodrome en‑route under planned conditions.
View termequivalent airspeed
Indicated airspeed corrected for compressibility effects at altitude, used for performance comparisons.
View termfixed‑reserve fuel
Fixed quantity of fuel required to be carried for emergencies as per regulatory minimum reserve rules.
View termground‑roll distance
The distance from brake-release or acceleration point to airplane lift-off during take‑off roll.
View termhead‑wind component
The component of the wind along the runway axis directed opposite to aircraft’s travel, used for performance calculations.
View termLanding distance available
Declared length of runway that is available and suitable for the ground run of an aircraft landing.
View termLanding distance required
Calculated distance an aircraft needs to land and come to a complete stop under existing conditions.
View termMaximum Brake-Energy Speed
The highest speed from which an aircraft can stop without exceeding the maximum brake energy limit, used to ensure brake system integrity and safety.
View termmaximum demonstrated cross-wind
The highest crosswind component at which satisfactory control was demonstrated during aircraft certification flight tests.
View termMaximum Tyre Speed
The highest ground speed a tire can sustain without risking structural failure, defined by aircraft and tire manufacturers.
View termoperating empty weight
The weight of an aircraft including all standard items and operating fluids but excluding payload and usable fuel.
View termpressure altitude
Altitude indicated when the altimeter is set to the standard pressure setting of 1013.25 hPa (29.92 inHg).
View termramp weight
The total weight of the aircraft while parked at the ramp, including fuel, payload, and all crew and equipment before engine start or taxi.
View termreference landing speed
Target speed established by crew to optimize landing safety and performance, typically VREF plus wind correction.
View termrunway‑length correction for slope and temperature
Adjustment applied to declared runway length to account for runway slope and ambient temperature effects on aircraft performance.
View termstandard‑atmosphere temperature lapse rate
The rate at which temperature decreases with altitude under standard atmospheric conditions, 2 °C per 1000 ft or 6.5 °C per 1000 m.
View termstopway length
The length of a stopway usable in the event of a rejected take-off, beyond the take-off run available.
View termTake-off distance available
Declared length of runway plus clearway that is available and suitable for the ground run of an aircraft taking off.
View termTake-off run available
Declared length of runway suitable for the ground run of an aircraft taking off, excluding clearway.
View termtake‑off safety speed
Target airspeed reached after V2 during take‑off, providing sufficient climb gradient with one engine inoperative.
View termtaxi‑in fuel
Estimated fuel required for taxiing after landing, including clearing runway and reaching gate.
View termtaxi‑out fuel
Fuel required for engine start, taxi, and contingencies before take-off.
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Minimum vertical profile flown after take‑off, reduced from gross climb to ensure obstacle clearance following critical-engine failure
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Climb segment from gear retraction to acceleration altitude with one-engine inoperative, maintaining prescribed gradient.
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Climb segment after acceleration and flap retraction up to en‑route climb altitude with one-engine inoperative.
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Minimum climb performance required during a go-around or missed approach with all engines operating.
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Imaginary inclined plane established to ensure minimum safe vertical separation between aircraft flight paths and obstacles.
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Lowest climb gradient required to ensure obstacle clearance or meet procedure design criteria.
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The highest level of engine thrust that can be used continuously without time limitation under normal operating conditions.
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Reduced engine thrust setting used for take-off to extend engine life, improve fuel efficiency, and meet noise abatement procedures.
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Take‑off Using An Assumed Temperature Higher Than Actual To Reduce Thrust And Prolong Engine Life While Meeting Performance Requirements.
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Thrust Less Than Maximum Take‑Off Thrust Applied During Take‑Off To Increase Engine Life And Optimize Operational Efficiency.
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Numeric Value From 0 To 6 Indicating The Braking Action And Surface Condition Of A Runway As Published In A Runway Condition Report.
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Pilot‑reported Assessment Of Actual Aircraft Braking Performance On A Runway Surface.
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Standardized Tool Used To Assign Runway Condition Codes Based On Surface Type And Contaminant Characteristics, Supporting Aircraft Performance Assessment.
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Vertical Thickness Of Water, Slush, Or Other Moisture‑Related Contaminants On The Runway Measured In Millimetres For Performance Calculations.
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Wind Blowing In The Same Direction As Aircraft Movement, Reducing Lift And Increasing Required Take‑Off Or Landing Distance.
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Wind Component Perpendicular To The Runway Centerline, Affecting Aircraft Lateral Control During Take‑Off And Landing.
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Wind Blowing Opposite To Aircraft Movement, Increasing Lift And Reducing Required Take‑Off Or Landing Distance.
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Length Of The Designated Area Beyond The Runway End That Can Be Used To Decelerate During A Rejected Take‑Off, As Part Of ASDA.
View termvariable‑reserve fuel
Additional reserve fuel calculated proportionally to flight time beyond the fixed reserve, for unforeseen delays.
View termvisual‑segment surface
An obstacle‑free area beyond the runway threshold, providing required visual clearance during the final approach segment.
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