Powerplant Failure During Takeoff

Two tolerances, both tighter than anything I flew for the commercial multi:

• After establishing a climb, maintain the desired airspeed ±5 knots, using the flight controls in the proper combination as recommended by the manufacturer, or as required, to maintain best performance, and trim as required (VII.B S4, AMEL/AMES)
• Maintain the appropriate heading ±5° when the powerplant failure occurs (VII.B S5, AMEL/AMES)

Both apply only to the multiengine ratings. There is no altitude tolerance in this task — the standard is climb performance, not a number, and the airspeed I hold is the one the AFM schedules for the configuration I am in.

Appendix 3 of the ACS is specific. In a multiengine airplane certificated with V1, VR, or V2 speeds, a simulated failure of the most critical powerplant should occur:

• After V1 and prior to V2, if appropriate under the prevailing conditions in the opinion of the evaluator; or
• As close as possible after V1 when V1 and V2, or V1 and VR, are identical

In an airplane certificated without V1, VR, or V2 speeds, the simulated failure should occur after reaching a minimum of VSSE, and if accomplished in the aircraft the evaluator should not introduce it lower than 400 feet AGL. Tests in an FSTD have no minimum altitude for introducing the failure (FAA-S-ACS-11A, Appendix 3, Area VII Task B) — though a practical test in an FSTD can only be accomplished as part of an approved curriculum or training program, and any limitations on powerplant failure will be noted there (Appendix 2).

Appendix 2 adds the general rule for the airplane: at altitudes lower than 3,000 feet AGL, powerplant failure should be simulated as recommended by the manufacturer — for propeller-driven airplanes, by reducing throttle to idle and then establishing zero thrust. The evaluator may also consult the airplane's FSB report for additional safety considerations.

The short form: V1 is critical engine failure speed, or takeoff decision speed — the speed at which the pilot is to continue the takeoff in the event of an engine failure or other serious emergency. Below V1 it is considered safer to stop within the accelerate-stop distance. It is also the minimum speed, following failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance (AFH ch. 16).

The expanded definition from AC 120-62, quoted in AFH ch. 16, is what airline training uses. V1 represents:

1. The maximum speed by which a rejected takeoff assures a safe stop within the remaining runway, or runway and stopway
2. The minimum speed which assures the takeoff can be safely completed within the remaining runway, or runway and clearway, after failure of the most critical engine at the designated speed
3. The single speed which permits a successful stop or continued takeoff when operating at the minimum allowable field length for a particular weight

My airplane's actual V1 comes from the AFM and the day's conditions — never from memory or from another type.

From AFH ch. 16:

• VEF — the speed used during certification at which the critical engine is assumed to fail. V1 follows VEF by the recognition interval.
• VR — rotation speed, the speed at which rotation to takeoff attitude is initiated. It cannot be less than V1 or less than 1.05 × VMC. On a single-engine takeoff it also allows for acceleration to V2 at the 35-foot height at the end of the runway.
• VLOF — lift-off speed, the speed at which the airplane first becomes airborne; an engineering term used in certification, which the pilot considers if the AFM lists it.
• V2 — takeoff safety speed, a referenced airspeed obtained after lift-off at which the required one-engine-inoperative climb performance can be achieved.

The chain in one sentence: fail at VEF, decide by V1, rotate at VR, leave the ground at VLOF, and be at V2 by 35 feet.

Both start the same way — accelerate to V1 with all engines at takeoff power and experience an engine failure at V1 (AFH glossary):

• Accelerate-stop distance — the distance to then abort the takeoff and bring the airplane to a stop using braking action only. Thrust reversing is not considered.
• Accelerate-go distance — the distance to continue the takeoff on the remaining engine(s), including the distance required to climb to 35 feet, by which time V2 must be attained.

That reversers are excluded from the certified accelerate-stop number is the point examiners like to draw out: reverse thrust is margin I may not get, not performance I may plan on.

Because of human reaction time. AFH ch. 16 quantifies it: delaying the RTO maneuver by just one second beyond V1 increases the speed 4 to 6 knots on average, and crews require 3 to 7 seconds to identify an impending RTO and execute the maneuver. If braking has not begun by V1, the decision to continue is made by default.

The practical consequence is that the go/no-go decision must be made before V1 so the stop can be initiated at V1. That gap is exactly why the FAA expanded the V1 definition and introduced minimum, maximum, and reduced V1.

A reduced V1 is a V1 less than maximum V1 or the normal V1, but more than minimum V1, selected to reduce the RTO stopping distance required (AFH ch. 16). The main purpose is to properly adjust the RTO stopping distance in light of the degraded stopping capability associated with wet or contaminated runways, while adding approximately 2 seconds of recognition time for the crew (AFH ch. 16).

The trade is real: a lower V1 buys stopping margin and costs go margin, so it is only available where the accelerate-go case still closes.

Most manufacturers recommend operators identify a low-speed regime (e.g., 80 knots and below) and a high-speed regime (e.g., 100 knots and above) of the takeoff run (AFH ch. 16):

• In the low-speed regime, reject for any malfunction or abnormality — actual or suspected
• In the high-speed regime, reject only for catastrophic malfunctions or life-threatening situations, weighing the threat against the risk of overrunning the runway

SOPs include a speed callout at the transition between regimes. That callout serves several purposes at once: it flags the impending critical decision window, gives a last chance to cross-check airspeed and confirm takeoff thrust is set, and acts as an incapacitation check through the challenge-and-response ritual (AFH ch. 16).

Brakes first, and simultaneously. AFH ch. 16 is emphatic that the instinctive error is to use normal after-landing braking:

• Apply maximum braking immediately while simultaneously retarding the throttles
• Spoiler extension and thrust reverser deployment follow in short sequence
• Avoid differential braking for directional control if possible — it diminishes braking effectiveness

Brakes provide the most effective stopping force; delaying the primary deceleration force during an RTO, when every second counts, increases stopping distance. And treat the whole event as what it is: "a rejected takeoff should be perceived as an emergency" (AFH ch. 16).

Fly the profile, and let the schedule — not instinct — drive configuration:

• Maintain directional control and keep the airplane on centerline; rudder stops the yaw
• Rotate at VR at the normal rate — approximately 2.5° to 3° per second to a takeoff pitch attitude normally between 10° and 15° nose up (AFH ch. 16)
• Achieve and hold the engine-out climb speed the AFM schedules, ±5 knots (VII.B S4)
• Gear up after a positive rate of climb is established and confirmed; note the VSI and altimeter may not show a positive climb until 35 to 50 feet due to ground effect (AFH ch. 16)
• Do not retract flaps until obstruction clearance altitude or 400 feet AGL has been passed (AFH ch. 16)
• Then run the memory items and the checklist, and only then think about a return

Every reference speed for my airplane — V1, VR, V2, the flap retraction schedule — is type-specific. I take them from the AFM and the FSB report, and recompute them for the day's weight, runway, gradient, temperature, pressure, wind, icing, and runway condition (AFH ch. 16).

Land. The ACS says that if a powerplant failure — simulated, if in the airplane — occurs after becoming airborne and before reaching an altitude where a safe turn can be made (ASEL, ASES), or the performance capabilities and operating limitations of the airplane will not allow the climb to continue (AMEL, AMES), the applicant should establish a power-off descent approximately straight ahead (VII.B S2; Appendix 3).

The AFH backs the reasoning with accident data: there is a very high success rate for engine-inoperative landings when the airplane is landed under control, and a very high fatality rate in stall-spin accidents when the pilot attempts flight beyond the performance capability of the airplane (AFH ch. 13). "Remaining airborne and bleeding off airspeed in a futile attempt to maintain altitude is almost invariably fatal."

The ACS makes briefing the plan its own risk element in a crew environment (VII.B R2). A briefing that satisfies it names, before the airplane moves:

• The speeds — V1, VR, V2 and who calls them
• The stop case — what to reject for below and above the low/high-speed transition, and who does what
• The go case — the target speed and pitch, the gear and flap schedule, and the initial altitude
• The path — runway heading or an engine-out procedure, terrain and obstacles, and the airport to return to
• The runway — length, surface condition, and any land and hold short operation in effect (R1)
• Contingencies — takeoff warning inhibit systems, wake turbulence behind a preceding heavy, and density altitude

AFH ch. 13 frames it the same way: "An emergency contingency plan and safety brief should be clearly understood well before the takeoff roll commences."

Behind the brief sits the data. Takeoff data — V1/VR and V2, power settings, and required field length — is computed prior to each takeoff from weight, runway length, gradient, temperature, pressure, wind, icing conditions, and runway condition, and recorded on a takeoff data card for any airplane without an FMS. Both pilots should review the data entered in the FMS, or compute it separately and cross-check. If plans change while taxiing, recalculate (AFH ch. 16).

Stopping the yaw, with rudder, immediately. AFH ch. 13: "Maintaining directional control with prompt and often aggressive rudder application and STOPPING THE YAW is critical to the safety of flight." Then:

• Ensure airspeed stays above VMC. If the yaw cannot be controlled with full rudder applied, reducing thrust on the operative engine is the only alternative
• Do not lead with aileron — attempting to correct the roll with aileron without first applying rudder increases drag and adverse yaw and further degrades directional control
• Then a slight bank toward the operative engine — at least 5° and a maximum of 10° initially to stop the yaw and maintain directional control, held only momentarily, just long enough to establish or ensure directional control
• Trim to lower the control forces

Note the pitch consequence in propeller airplanes: the attitude for the engine-out climb speed is lower than the one for the all-engine best rate of climb (AFH ch. 13).

Once directional control is established and the airplane is configured for climb, reduce the bank to that producing best climb performance — without specific guidance for zero sideslip, AFH ch. 13 suggests a bank of 2° with one-third to one-half ball deflection toward the operative engine. The initial 5-to-10° is momentary precisely because climb performance suffers when bank angles exceed approximately 2 or 3°.

From AFH ch. 13:

• Identify — determine which engine failed primarily through the control inputs required to maintain straight flight, not the engine gauges. Confirmation on the gauges may or may not be possible depending on the failure mode.
• Verify — retard the throttle of the engine thought to have failed. No change in performance verifies correct identification.
• Feather — bring the corresponding propeller control fully aft.

Most AFM memory items sequence it as: assume the engine-out climb speed, set takeoff power, retract flaps and landing gear (on some airplanes gear before flaps), then identify, verify, and feather. Then, and only then, review the printed copy as time permits and run the securing failed engine checklist. Unless I suspect a fire, "the remaining items should be accomplished deliberately and without undue haste. Airplane control should never be sacrificed to execute the remaining checklists" (AFH ch. 13).

Not before I have altitude to spend. AFH ch. 13 directs that because turning flight reduces climb performance, the climb should be made straight ahead or with shallow turns to avoid obstacles to an altitude of at least 400 feet AGL before attempting a return to the airport.

In a transport-category operation the answer is usually more constrained still: I fly the published or company engine-out departure procedure to the specified altitude, because the obstacle analysis behind my takeoff weight assumed that exact path. Deviating from it invalidates the numbers that let me take off at that weight.

Land straight ahead. AFH ch. 13: keep the nose as straight as possible, close both throttles, adjust pitch attitude to maintain adequate airspeed, and descend to the runway. Concentrate on a normal landing and do not force the aircraft on the ground. Land on the remaining runway or overrun.

The handbook is candid that there are "really no other practical options" — the chances of maintaining directional control while retracting flaps, retracting the gear, feathering the propeller, and accelerating are minimal. Depending on how quickly I react to the sudden yaw, the airplane may run off the side of the runway by the time action is taken. And on airplanes with a single engine-driven hydraulic pump, failure of that engine means the only way to raise the gear is to windmill the engine or use a hand pump — "not a viable alternative during takeoff."

A landing needs to be accomplished on whatever essentially lies ahead (AFH ch. 13). There is also the option of continuing ahead in a descent at the engine-out best rate of climb speed with the remaining engine producing power — as long as I am not tempted to remain airborne beyond the airplane's performance capability.

"The greatest hazard in a single-engine takeoff is attempting to fly when it is not within the performance capability of the airplane to do so. An accident is inevitable" (AFH ch. 13). Landing under control is paramount.

VII.B K2 lists them, and each has a consequence:

• Runway length and surface condition — drive V1 selection and whether the accelerate-stop case closes; a wet or contaminated runway may call for a reduced V1 (AFH ch. 16)
• Density altitude and environmental conditions — reduce both thrust available and climb gradient, which can move the scenario from "adequate climb performance" to "inadequate"
• Obstructions — set the engine-out departure path and the altitude at which flaps may come up
• Takeoff warning systems, including inhibit logic — some manufacturers inhibit aural or visual warnings of non-critical equipment beyond a preset speed, specifically to prevent an overreaction and a risky high-speed RTO (AFH ch. 16). Know what the airplane will and will not indicate after that speed.
• Wake turbulence — a rolling upset with an engine out is not survivable at low altitude; spacing is part of the plan
• Sideslip, bank angle, and rudder input — the certified climb performance assumes the AFM's engine-out technique, not an improvised one

R1 folds in one more: land and hold short operations, which shorten the runway available for a stop.

The failure compresses decisions into seconds at low altitude — exactly where fixation kills. Airplanes have been lost "due to apparent fixation on the engine problem to the detriment of flying the airplane," and airplane control is never sacrificed to execute the remaining checklists (AFH ch. 13). Fly first, secure second.

Structure defends against the rest. The takeoff brief (R2) converts the failure into a pre-made plan rather than a low-altitude discussion; the regime speed callout doubles as an incapacitation check (AFH ch. 16); and the identify-verify-feather discipline exists because a rushed, disoriented crew is what shuts down the wrong engine. If situational awareness degrades — position, altitude, terrain, where the airport went — say so, and use ATC to rebuild the picture before continuing the drill.

• Late rotation. In training it is common to overshoot VR and then V2 because the pilot monitoring calls for rotation at or just past VR and the pilot flying visually verifies before rotating. A delayed rotation can be critical when runway length or obstacle clearance is limited, and on some airplanes the rapidly increasing airspeed causes the achieved flightpath to fall below the engine-out scheduled flightpath (AFH ch. 16). Rotate on the call.
• Rotating too soon or too fast. Rotation to the proper takeoff attitude too soon may extend the takeoff roll or cause an early lift-off, resulting in a lower rate of climb and a divergence from the predicted flightpath (AFH ch. 16).
• Chasing altitude instead of speed. The tolerance is airspeed ±5 knots (VII.B S4); the airplane will climb at whatever rate it has.
• Retracting flaps early to reduce drag — the schedule exists because obstacle clearance was computed with them where they are (AFH ch. 16).
• Heading drift. ±5° (VII.B S5) is a rudder-and-trim discipline, not a heading-bug problem.