ATPL Flight Performance and Planning cheat sheet

TORA is the length of runway declared available and suitable for the ground run of an aeroplane taking off; TODA = TORA plus clearway (clearway max 50% of TORA, no obstacles, not counted as ground run).

ASDA = TORA plus stopway; the stopway must be at least as wide as the runway and capable of supporting the aeroplane without structural damage.

Screen height at the end of TODA: 35 ft for CS-25/FAR-25 aeroplanes, 50 ft for CS-23/FAR-23 (commuter category) aeroplanes; V2 must be reached by 35 ft (CS-25).

Balanced field length: the TORR cleared in an all-engines-operating take-off equals the ASDR in the one-engine-inoperative case; achieved by the balanced V1.

V1 is the decision speed: before V1 an engine failure allows a stop within ASDA; at or after V1 the take-off can be continued to 35 ft within TODA. V1 must lie between VMCG and VR.

VMCG is the minimum control speed on the ground with the critical engine failed and the aeroplane on the ground; VMCA is the minimum control speed in the air; VMCL is the minimum control speed in the landing configuration.

Take-off mass limits: MTOM structural, MTOW performance-limited (field length, obstacle, climb, tyre speed, brake energy); the lowest of these governs.

Runway slope, wind, temperature, pressure and runway surface condition (dry, wet, contaminated) must be applied to AFM take-off data; wet runway increases the accelerate-stop distance and reduces V1.

CS-25 climb segments: take-off (first segment) 0.5% for two-engine, 0.3% for three-engine, 0.3% for four-engine at V2, gear down, take-off flaps.

Second segment: 2.4% two-engine, 2.7% three-engine, 3.0% four-engine; gear up, take-off flaps, V2, at 35 ft screen height.

Third (transition) segment: flaps retracted, speed V2 to VFTO, 35 ft to 400 ft; no percentage gradient requirement but the aeroplane must maintain a positive climb.

Fourth (final take-off) segment: 1.2% two-engine, 1.5% three-engine, 1.7% four-engine; flaps up, VFTO, 400 ft to 1500 ft.

En-route climb (CS-25.123): one-engine-inoperative gradient 1.1% two-engine, 1.4% three-engine, 1.6% four-engine, at 1500 ft above the aerodrome and at the planned cruise altitude.

Landing climb: 3.2% two-engine, 3.4% three-engine, 3.6% four-engine with all engines operating; 2.1%, 2.2%, 2.3% respectively with one engine inoperative; approach flaps, gear down.

Climb gradient (%) = 100 × (thrust − drag) / weight; rate of climb (ft/min) = gradient (%) × TAS (kt) × 101.3 / 60 approximately, or ROC = 60 × TAS × gradient / 100.

Climb speed: VY (best rate) is lower than VX (best angle); for obstacle clearance use VX, for fastest height gain use VY; VX increases with altitude and equals VY at absolute ceiling.

LDA is TORA minus the displaced threshold; the landing distance available must not be less than the landing distance required (LDR).

Certification landing distance (CS-25) is from 50 ft above the threshold to a full stop; the actual landing distance must be multiplied by 1.67 (dry) or 1.92 (wet) for operational planning, or per operator's approved factor.

Wet runway: the required landing distance increases by approximately 15% and reverse thrust credit is limited; contaminated runways require the AFM contaminated landing data.

Landing mass limit: MLW structural and performance-limited; approach climb gradient (2.1% for two-engine) and landing climb gradient (3.2%) must be satisfied at the destination and alternate.

Autobrake settings affect the stopping distance and brake energy; MAX autobrake is limited by brake energy and tyre speed, not just runway length.

Runway slope on landing: 2% uphill reduces LDR; downhill increases it; published landing distances are for level runway unless stated.

Reverse thrust is not credited in the certified landing distance but may be credited in some operational calculations; the aircraft must be able to stop without reverse thrust.

Displaced threshold reduces LDA but not TORA; landing distance is measured from the threshold, so a displaced threshold reduces the usable landing length.

Obstacle clearance in the take-off flight path: net take-off flight path (gross minus 0.8% for two-engine, 0.9% for three-engine, 1.0% for four-engine) must clear all obstacles by 35 ft vertically or 90 m horizontally.

En-route obstacle clearance: the net en-route flight path (gross minus 1.1% two-engine, 1.4% three-engine, 1.6% four-engine) must clear all obstacles by 1000 ft in the en-route phase.

Contaminated runway: use AFM data for slush, snow, ice, standing water; braking action is reported as good, medium, poor or nil; nil braking action requires a landing at an alternate unless certified.

Contaminated runway take-off: reduced V1 and increased accelerate-stop distance; the take-off must be rejected if the braking action deteriorates below the AFM limit.

Driftdown: with one engine inoperative the aeroplane descends to the single-engine service ceiling; the driftdown net flight path must clear obstacles by 1000 ft.

ETOPS/EDTO: the en-route alternate must be within the approved diversion time at one-engine-inoperative cruise speed; fuel must cover diversion plus 15% hold at 1500 ft.

The one-engine-inoperative net flight path must clear obstacles by 1000 ft in the en-route phase; the gross gradient minus the 1.1% (two-engine) net factor gives the net path.

Take-off obstacle clearance: the net take-off flight path must clear obstacles by 35 ft vertically or 90 m horizontally; if not, reduce mass or use improved climb.

MTOM is the maximum certificated take-off mass; MLM is the maximum landing mass; MZFM is the maximum zero-fuel mass; these are structural limits.

Zero fuel mass = dry operating mass + traffic load; it must not exceed MZFM. Take-off mass = ZFM + take-off fuel.

Dry operating mass (DOM) = basic empty mass + crew + crew baggage + catering + potable water; it excludes traffic load and usable fuel.

Maximum zero fuel mass = MTOM minus the fuel needed for the flight to the destination plus reserves; MZFM is the limit on the payload plus DOM.

Centre of gravity limits: forward CG limit is set by elevator authority and landing flare; aft CG limit is set by stability and stall recovery.

CG position (%MAC) = (CG arm − LE MAC arm) / MAC length × 100; MAC is the mean aerodynamic chord.

Load sheet: the CG must lie within the certified envelope for take-off, in-flight and landing; fuel burn moves the CG as fuel is consumed.

Maximum floor loading and maximum running load (kg per metre) must not be exceeded; the load must be distributed to keep the CG within limits.

Moment = mass × arm; total moment = sum of individual moments; CG arm = total moment / total mass.

CG shift = (mass moved × distance moved) / total mass; moving mass aft moves the CG aft by that amount.

Adding or removing mass: new CG = (old total moment ± added mass × its arm) / (old total mass ± added mass).

Index method: index = (moment / constant) + constant; the load sheet uses index units to simplify CG calculation.

Load sheet contains: DOM, traffic load, take-off fuel, trip fuel, taxi fuel, ZFM, TOM, LM, CG position, and the trim setting.

Fuel density: kerosene 0.78–0.81 kg/L (typical 0.80); AVGAS 100LL approximately 0.72 kg/L; density varies with temperature.

Underload = allowed mass − actual mass; the limiting mass (MTOM, MLM, MZFM) determines the maximum payload.

Take-off CG must be within the take-off envelope; landing CG must be within the landing envelope; the most restrictive condition governs the fuel/payload distribution.

Trip fuel: fuel from take-off to landing at the destination; includes climb, cruise, descent and approach.

Contingency fuel: 5% of trip fuel, or 3% with an en-route alternate, or 20 minutes holding at 1500 ft, or a statistical method (operator-approved).

Alternate fuel: fuel from the destination to the alternate, including missed approach, climb, cruise, descent and approach.

Final reserve: 30 minutes holding at 1500 ft above the alternate in ISA conditions; for turbine aeroplanes this is the minimum final reserve.

Additional fuel: fuel for the case where the destination and alternate are unavailable; must allow 15 minutes holding at 1500 ft.

Taxi fuel: fuel for APU, taxi-out and taxi-in; it is not part of trip fuel but is included in block fuel.

Block fuel = taxi fuel + trip fuel + contingency fuel + alternate fuel + final reserve + additional fuel + extra fuel.

Fuel density and temperature: fuel mass = volume × density; density decreases with temperature, so the same volume gives less mass at high temperature.

Destination alternate: required unless the destination has an approved instrument approach and the weather forecast allows a visual approach and landing.

Weather minima for the destination alternate: ceiling and visibility must be at or above the alternate minima; the alternate must be within the fuel range.

En-route alternate: used for ETOPS/EDTO and for contingency fuel; must be within the diversion time at one-engine-inoperative cruise speed.

Contingency planning: the pilot must plan for a diversion to an en-route alternate if the destination becomes unavailable; fuel must cover the diversion.

Route planning: the great circle route is the shortest distance; the rhumb line is a constant heading; wind and temperature affect the optimum route.

Equal time point (ETP): the point where the time to the destination equals the time to the alternate; used for diversion planning.

Point of no return (PNR): the point beyond which the aeroplane cannot return to the departure aerodrome with the remaining fuel.

Alternate minima: the alternate must be forecast to be at or above the published minima for the expected approach; if not, a second alternate is required.

Computer flight plan (CFP) contains: route, waypoints, tracks, distances, winds, temperatures, cruise levels, fuel, times and masses.

The operational flight plan (OFP) is the document signed by the commander; it includes the CFP, fuel plan, load sheet and the commander's acceptance.

CFP fuel figures must be checked against the manual/performance calculation; the commander is responsible for the final fuel decision.

Aircraft performance in the CFP is based on the AFM; the operator's approved performance software must be used for the final figures.

The OFP must include the take-off and landing mass, the fuel figures, the route, the alternates and the commander's signature.

CFP winds and temperatures are forecast values; the actual fuel burn may differ, so in-flight monitoring is required.

The CFP must be checked for gross errors: route, waypoints, fuel, masses and times; a cross-check against the manual plan is good practice.

OFP documents must be retained for the operator's record-keeping period; the commander signs to confirm the plan is acceptable.

Fuel monitoring: compare actual fuel remaining with the planned fuel at each waypoint; a negative trend requires a decision to replan or divert.

In-flight replanning: recalculate the fuel required to the destination and alternate; if the remaining fuel is insufficient, divert to an en-route alternate.

The minimum fuel at destination is the final reserve plus alternate fuel; if the remaining fuel falls below this, declare a fuel emergency.

Fuel jettison: if the landing mass exceeds MLM, jettison fuel to reduce to MLM; the jettison must be completed before landing.

The commander must monitor fuel against the flight plan; a significant deviation (e.g. more than 5%) requires a re-check of the plan.

In-flight replanning must consider the actual winds, temperatures and aircraft performance; the new plan must be checked against the fuel remaining.

Fuel emergency: declare MAYDAY FUEL when the fuel remaining is below the final reserve; the aircraft must land at the nearest suitable aerodrome.

The OFP must be updated in flight with actual fuel and time; the commander signs the amended plan if required by the operator.