Private pilot · ACS PA.IX.E
Engine Failure During Takeoff Before VMC (Simulated)
Before you can fly on one engine, a twin with an engine failure is an airplane that needs to stop.
This lesson is written for multi-engine land or multi-engine sea. You picked single-engine land: speeds, altitudes and procedures differ, so follow your POH/AFM and your instructor.
Why this one matters
An engine failure on the roll is survivable when the reaction is immediate: close both throttles and stop. Trying to fly before the airplane can be controlled on one engine leads to yaw and roll near the ground. The decision is made before the takeoff, in the briefing.
Can’t miss
- •Engine failure on the roll: close both throttles smoothly and promptly, keep directional control, brake and stop. No blue line, no memory items, no feathering: those belong to a failure after liftoff.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Private Pilot ACS (FAA-S-ACS-6C), PA.IX.E.S1-S2)
- •The decision is by phase, not just speed: on the roll, or just airborne with the gear still down and runway ahead, close both throttles and land or stop straight ahead, even above published VMC.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- •Keep it straight with rudder first, then nosewheel steering and brakes (land) or the flight controls (water).(Private Pilot ACS (FAA-S-ACS-6C), PA.IX.E.S2)
- •Published VMC (the red line) is the slowest speed at which you can keep control with the critical engine suddenly inoperative, then hold straight flight with no more than 5° of bank. It is set under fixed conditions: sea-level standard day; maximum takeoff power on the operating engine; the critical engine windmilling with its propeller control in the takeoff position; the most unfavorable weight (the lightest) and the most unfavorable (aft) center of gravity; gear up; wing and cowl flaps and trim in the takeoff position; out of ground effect; no more than 5° of bank toward the operating engine; heading held within 20° with no more than 150 pounds of rudder force.(14 CFR 23.149 (now 23.2135); Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- •Accelerate-stop distance: the runway needed to accelerate to a specified speed (often rotation), have an engine fail at that moment, and stop. In most light twins it is advisory data, not a limitation: compare it with the runway at today's weight and density altitude.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Your airplane's POH/AFM)
- •Brief every takeoff: what you will do with a failure on the roll, just after liftoff with runway left, and once the gear is up.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- •Configure by the checklist; a mis-set mixture or fuel selector is a common cause of a takeoff power loss.(Your airplane's POH/AFM)
What you should know
VMC and the speeds K1 · K2
- Published VMC (the red line) is the slowest speed at which you can keep control with the critical engine suddenly inoperative, then hold straight flight with no more than 5° of bank. It is set under fixed conditions: sea-level standard day; maximum takeoff power on the operating engine; the critical engine windmilling with its propeller control in the takeoff position; the most unfavorable weight (the lightest) and the most unfavorable (aft) center of gravity; gear up; wing and cowl flaps and trim in the takeoff position; out of ground effect; no more than 5° of bank toward the operating engine; heading held within 20° with no more than 150 pounds of rudder force.(14 CFR 23.149 (now 23.2135); Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- Your real VMC differs whenever the conditions do. It goes up with a windmilling propeller (feathering lowers it), an aft CG, lighter weight, more power on the operating engine, and less bank toward it. It goes down with less power (a normally aspirated engine at altitude; a turbocharged one only above its critical altitude), gear extended (keel effect), and ground effect.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- Bank matters most: VMC rises more than 3 knots for each degree of bank less than 5°, and with the wings level control can be lost almost 20 knots above the published red line. Up to 5° toward the operating engine is the certification number, not the way you fly.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- The critical engine is the one whose failure is hardest to control: on twins with both propellers turning clockwise (seen from behind), the left, because of P-factor, accelerated slipstream, spiraling slipstream and torque. Twins with counter-rotating propellers (a Seminole or a Duchess) have no critical engine.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- VMC (red line): minimum control speed. VYSE (blue line): best rate of climb, or least loss, on one engine. VXSE: best angle on one engine. VSSE: safe single-engine speed, the slowest at which an engine may be intentionally failed in training.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Distances K3
- Accelerate-stop: accelerate to a specified speed, have an engine fail, and stop. Accelerate-go: accelerate, lose an engine at that speed, and continue on the other to 50 feet. Many light twins publish only accelerate-stop.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Your airplane's POH/AFM)
- If accelerate-stop exceeds the runway, a failure near rotation may leave you off the end: reduce weight, wait for cooler air, or use a longer runway.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- A wet or contaminated runway, a downhill slope or a tailwind all lengthen the stop; on a wet runway braking is weaker and the tires can hydroplane, so brake firmly but modulate.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
The decision and the stop R1 · R2 · R3
- Brief it before the roll: "Failure before liftoff, or with the gear still down and runway ahead: I close both throttles and stop or land straight ahead." Continue only once airborne, gear coming up, at or above VXSE (or VMC + 5 knots), with single-engine climb assured at today's weight and density altitude.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- The stop: both throttles closed, directional control with rudder, then nosewheel steering and differential braking as speed falls; maximum braking without locking the wheels or losing control. Brief what is past the end of the runway in case of an overrun.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
- Configure by the checklist: mixtures, propellers, fuel selectors, trim, flaps, cowl flaps.(Your airplane's POH/AFM)
- In training the instructor or evaluator simulates the failure by closing one throttle at a low, safe speed on the roll; the engine is never shut down or feathered on the runway, and no failure is introduced in flight below VSSE.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Private Pilot ACS (FAA-S-ACS-6C), Appendix 2)
- A failure on the roll is startling. The briefing turns the reaction into one action: both throttles closed. Then keep straight and stop.(Risk Management Handbook (FAA-H-8083-2A))
On the flight
ACS standards
- Close the throttles smoothly and promptly at a simulated engine failure.(Private Pilot ACS (FAA-S-ACS-6C), PA.IX.E.S1)
- Maintain directional control and apply brakes (AMEL) or flight controls (AMES) as needed.(Private Pilot ACS (FAA-S-ACS-6C), PA.IX.E.S2)
What your instructor is watching for
Your instructor watches for a takeoff briefing, an immediate close of both throttles, straight tracking on the centerline with rudder, steering and brakes, a firm controlled stop, and no attempt to fly.
Scenarios
Decide what you would do first, then see the worked answer.
At 60 knots on the roll, with VMC at 65, the left engine sputters.
What do you do? See the worked answer
Close both throttles, keep straight with right rudder, then steering and brakes, and stop.
Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes
Just airborne, gear still down, plenty of runway left, the right engine quits.
What do you do? See the worked answer
Close both throttles and land straight ahead on the remaining runway.
Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes
Hot day, heavy, short runway.
What do you check before departing? See the worked answer
Accelerate-stop distance against the runway, accelerate-go if published, and single-engine climb against the terrain; if they don't work, change the plan.
Your airplane's POH/AFM
Common mistakes
Hesitating.
Each second uses runway.
Instead: Brief the action; close both throttles at once.
Closing only one throttle.
Asymmetric thrust swerves the airplane.
Instead: Both throttles closed.
Starting the airborne flow (blue line, feather) on the runway.
It delays the stop and invites an attempt to fly.
Instead: On the roll the only actions are throttles closed, straight, stop.
Now train it
Say it out loud, hear it asked, and take the quick check in this lesson’s practice pack. It tracks your shaky spots.
Got it?
When it feels solid, practice engine failure during takeoff before vmc (simulated) out loud with our examiner.
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Go to the source (free)
Teaching this? The instructor lesson plan →
Sources
- Airplane Flying Handbook (FAA-H-8083-3C): Transition to Multiengine Airplanes
- Instrument Flying Handbook (FAA-H-8083-15B)
- Risk Management Handbook (FAA-H-8083-2A)
- Private Pilot ACS (FAA-S-ACS-6C): Areas IX and X (multiengine)
- Your airplane's POH/AFM: Emergency Procedures; Performance
- 14 CFR 23.149 (now 23.2135): Minimum control speed
Study aid, not FAA guidance. Regulations change; check the current text at eCFR and the ACS. Checked against current sources 2026-11-13.