At the moment an engine fails during the takeoff roll, the clock is already running on one of the most critical decisions in transport aviation: continue or reject? The answer hinges on a single speed — V1, the takeoff decision speed. If the failure occurs at or after V1, the aircraft must be flown into the air. The runway remaining is no longer sufficient to stop safely, and the only path forward is a controlled, disciplined departure on the remaining thrust. For ATP candidates and line pilots alike, mastering the continued takeoff profile after an engine failure at V1 is not optional — it is the fundamental competency that the entire engine-out certification framework is built around.
This article explains the mechanics of that profile from the moment of V1 through the initial climb segment, the regulatory performance guarantees that underpin the procedure, and the common errors that cost pilots both on the checkride and — tragically — in real operations.
The V-Speed Framework
Before walking through the profile, the key V-speeds must be firmly understood because each one defines a specific phase of the continued takeoff.
- V1 (Takeoff Decision Speed): The speed by which the pilot must have initiated a stop if rejecting, or must be committed to flight if continuing. After V1, the takeoff must be continued regardless of failures.
- VR (Rotation Speed): The speed at which the pilot initiates the rotation to the takeoff attitude. VR is always at or above V1.
- VLOF (Lift-Off Speed): The speed at which the aircraft actually becomes airborne. It occurs at or shortly after rotation.
- V2 (Takeoff Safety Speed): The minimum airspeed that must be maintained from 35 feet above the runway surface to the end of the takeoff flight path with one engine inoperative. This is the target climb speed and is the benchmark against which all climb performance is measured.
These speeds are computed during preflight performance planning for the specific weight, configuration, pressure altitude, temperature, and runway conditions of that departure. They are not arbitrary — they are derived from certification flight testing and represent the edges of guaranteed performance.
How the Continued Takeoff Profile Works
From V1 to Rotation
If the engine failure occurs exactly at V1, the pilot has essentially zero time for a rejected takeoff because the decision to stop must already have been made before V1. The takeoff is therefore continued. The remaining thrust from the operating engine(s) — and in a two-engine aircraft that means only one engine — must accelerate the aircraft from V1 to VR. During this interval, the asymmetric thrust creates a strong yawing moment toward the failed engine. The pilot must apply and hold sufficient rudder input toward the operating engine to maintain directional control and keep the aircraft aligned with the runway centerline. This is not a gentle correction; at high thrust settings the rudder input can be substantial.
Rotation
At VR, the pilot initiates a smooth, steady rotation to the engine-out climb attitude. The Airplane Flying Handbook (FAA-H-8083-3C) emphasizes that rotation technique in the engine-out continued takeoff must be deliberate but not abrupt. Over-rotation can increase drag and reduce the rate of acceleration to V2; under-rotation can cause a tail strike on some aircraft or delay lift-off, consuming additional runway. The target is to achieve the appropriate pitch attitude that will allow the aircraft to accelerate to and maintain V2 during the initial climb.
Lift-Off and Initial Climb to 35 Feet
The aircraft becomes airborne at VLOF and the gear leaves the runway. At this instant the pilot must resist any temptation to raise the nose further. The objective is to reach 35 feet above the runway elevation — which is the reference point for the takeoff flight path — at V2 or above. The segment from lift-off to 35 feet is called the first segment of the takeoff flight path. Performance certification requires that the aircraft demonstrate a positive climb gradient during this segment with gear down (or retracting) and all engines at the go-around or takeoff thrust setting except the failed engine.
Gear retraction is typically initiated as soon as a positive rate of climb is confirmed and there is no runway remaining to land on. The pilot must verify a positive rate on the vertical speed indicator or altimeter before calling for gear up, because lowering the gear again from a low altitude with one engine inoperative could be catastrophic.
First Segment to Second Segment: 35 Feet to 400 Feet
Once airborne and above 35 feet, the aircraft enters the second segment climb. The defining conditions of this segment are: gear retracted, flaps/slats in the takeoff configuration, operating engine(s) at takeoff thrust (or maximum available thrust), and the target airspeed is V2. FAA regulations (14 CFR 25.121(b)) require a minimum climb gradient of 2.4% for two-engine aircraft, 2.7% for three-engine aircraft, and 3.0% for four-engine aircraft during the second segment, with the critical engine inoperative and in the second-segment configuration and thrust setting specified by the regulation. These are minimums; actual gradients on a properly performance-planned flight will exceed these values. The second segment continues to 400 feet above runway elevation, at which point the crew begins the acceleration segment.
Acceleration Segment: 400 Feet and Above
At 400 feet AGL, the aircraft may begin accelerating from V2 to the final segment climb speed (typically the engine-out en route climb speed or the flap retraction speed schedule). During this segment, thrust may remain at takeoff (or be reduced to maximum continuous thrust, depending on the time limits for the thrust setting used during departure), and flaps are retracted on schedule. The pilot must monitor airspeed carefully — allowing the speed to decay below V2 at any point during this phase reintroduces the risk of inadequate climb performance and possible loss of control near the ground.
Final Segment: Flap Retraction to 1,500 Feet
The acceleration (third) segment ends once the aircraft is clean (flaps/slats fully retracted) and has reached the final segment climb speed. At that point the final segment begins and continues to the end of the takeoff flight path, typically 1,500 feet above the runway. At 1,500 feet, the crew typically transitions thrust to maximum continuous (if not already done) and begins normal after-takeoff checklist actions. Engine-out abnormal procedures are addressed in coordination with the manufacturer's QRH.
Control Technique: Managing Asymmetric Thrust
The greatest handling challenge in the engine-out continued takeoff is directional control. With one engine producing full takeoff thrust and the other producing zero (or drag), the aircraft yaws and rolls toward the dead engine. The correct technique — consistent across virtually all transport-category aircraft — is:
- Apply rudder toward the operating engine to arrest the yaw.
- Use a slight bank into the operating engine (typically up to 5 degrees, per the specific aircraft's AFM guidance) primarily to reduce drag and achieve a zero-sideslip condition, which improves climb performance.
- Do not bank more than 5 degrees below 400 feet; excessive bank reduces the climb gradient and the vertical component of lift.
- Maintain V2 — not below, not significantly above (excess speed costs climb gradient on obstacle-limited departures).
The Airplane Flying Handbook specifically notes that pilots must use rudder as the primary directional control surface, not aileron, and that proper rudder application can arrest the yaw before it becomes an uncontrollable roll condition.
Why This Matters: Obstacle Clearance and the Takeoff Flight Path
The entire segment structure — first, second, acceleration, and final — exists to ensure the aircraft clears obstacles in the departure corridor. The takeoff flight path is the path from lift-off to 1,500 feet that the aircraft must follow to guarantee 35 feet of clearance above all obstacles in the departure corridor (with specific additional margins for the net takeoff flight path used in planning). Every V-speed and every segment climb gradient minimum is derived to guarantee that an aircraft suffering an engine failure exactly at V1 will still safely clear those obstacles. This is why performance planning is regulatory, not advisory.
Key Numbers and Rules
- V1 ≤ VR ≤ V2: The speed relationship that must always hold true.
- 35 feet AGL: The screen height at which the takeoff flight path begins and at which V2 must be achieved.
- 400 feet AGL: The minimum height before beginning acceleration and flap retraction.
- 1,500 feet AGL: The end of the takeoff flight path; when normal climb speed and thrust are established.
- ≤5 degrees of bank below 400 feet during engine-out climb.
- Minimum second-segment gradient: 2.4% (twin), 2.7% (tri-jet), 3.0% (quad).
- V2 must be maintained throughout the second segment — it is the minimum safe engine-out airspeed in the climb configuration.
Common Test Traps
- Confusing V1 with the point of engine failure: V1 is the decision speed, not the failure recognition speed. If a failure is recognized before V1, the reject decision must be made before V1 is reached. At V1, the go decision is made regardless of when the failure occurred.
- Thinking VR and V2 are always the same: They are distinctly different speeds. VR initiates rotation; V2 is the climb target. The precise relationship between VR and V2 depends on aircraft type and performance limits — on many transports V2 is close to or somewhat above VR, but this is not a fixed universal margin.
- Over-banking after liftoff: Many students instinctively want to bank steeply to prevent the yaw. Banks exceeding 5 degrees below 400 feet reduce climb gradient and can violate obstacle clearance margins.
- Accelerating above V2 in obstacle-limited situations: Flying faster than V2 in the second segment feels safer but reduces the climb angle, which may cause an obstacle clearance violation.
- Raising gear before confirming positive rate: On engine-out departures the temptation to clean up quickly is understandable, but premature gear retraction before confirming positive rate of climb can result in a wheels-up return to the runway.