Engine Failure After Take-off in a Crosswind with Obstacle
You are taking off in a light twin turboprop from a 1600 m runway at a coastal airport, elevation 15 ft, OAT 32°C, QNH 1010 hPa. Runway 09, surface wind 050/15 kt. There is a 15 m obstacle 300 m beyond the runway end. The aircraft's AFM gives: take-off distance to 50 ft in ISA sea level, still air, 900 m; the runway slope is 0.5% downhill; the AFM provides corrections of +1% per 1000 ft pressure altitude, +1% per °C above ISA, and a 10% factor for a 50% increase in take-off mass - not applicable. The aircraft's V1 is 100 kt, VR 105 kt, V2 110 kt. At 400 ft AGL, the right engine fails. The aircraft has a maximum single-engine climb gradient of 2.1% at 400 ft in these conditions.
1. Compute the pressure altitude and ISA deviation, and estimate whether the take-off distance available is sufficient with the wind and slope corrections.
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Pressure altitude = elevation + 30 × (1013 − QNH) = 15 + 30 × (1013 − 1010) = 15 + 90 = 105 ft. ISA temperature at 105 ft is about 15 − 2 = 13°C; OAT 32°C gives an ISA deviation of +19°C. Corrections: pressure altitude +1% per 1000 ft → negligible (0.1%). Temperature +1% per °C above ISA → +19%. Wind: 050/15 on runway 09 (090°) is 40° off, giving a headwind component of 15 × cos 40° ≈ 11.5 kt, which reduces take-off distance by roughly 1.5% per 10 kt headwind, i.e. about −1.7%. Slope 0.5% downhill reduces distance by about 5% per 1% downhill, so −2.5%.
Net: 900 × 1.001 × 1.19 × 0.983 × 0.975 ≈ 900 × 1.141 ≈ 1027 m to 50 ft. The runway is 1600 m, so the take-off distance to 50 ft is comfortably within the runway. However, the obstacle at 300 m beyond the end must be cleared: the aircraft reaches 50 ft at about 1027 m, so it is at 50 ft with 273 m of runway remaining plus 300 m to the obstacle, i.e. 573 m to climb 15 m (about 49 ft). That requires a climb gradient of 49/573 ≈ 8.5%, which the aircraft cannot achieve on one engine at 2.1%. On two engines it may, but the obstacle clearance must be checked from the AFM net take-off flight path, not assumed.
2. At 400 ft the right engine fails. Describe your immediate actions and the decision logic for continuing versus rejecting the take-off.
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At 400 ft the aircraft is above the decision point; V1 has long passed, so the take-off must be continued - a reject above V1 is not an option. Immediate actions: maintain control with rudder and aileron into the live engine, pitch to maintain V2 (110 kt) or V2 + 5, identify the failed engine, feather it, and apply maximum continuous power on the live engine. Do not retract flaps until a safe climb is established and the AFM procedure says so. Check the engine failure checklist and confirm the gear is up.
The single-engine climb gradient of 2.1% at 400 ft is marginal. At 110 kt groundspeed (roughly 110 kt with the headwind component), 2.1% gradient gives a climb rate of about 110 × 101.3 × 0.021 / 60 ≈ 3.9 ft/s ≈ 230 ft/min. That is a positive climb but very low. With the 15 m obstacle behind you and terrain ahead, the priority is to turn toward the crosswind (the wind is from 050°, so turning left toward 050° reduces the crosswind and may improve performance) and to climb to a safe altitude before troubleshooting further. Communicate with ATC: declare MAYDAY, request priority and a return for landing. Do not attempt to return to the runway below 400 ft - fly a circuit at a safe speed and altitude, then land.
3. If the aircraft had been at 100 ft when the engine failed, how would your decision differ?
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At 100 ft, still above V1 (100 kt) and below 400 ft, the aircraft is in the most critical low-altitude regime. A reject at 100 ft with insufficient runway remaining is generally more dangerous than continuing, but the decision depends on whether the aircraft can climb. At 100 ft with one engine, the 2.1% gradient at 400 ft may be lower at 100 ft (often less favourable due to ground effect and speed). The judgement: continue the take-off, maintain V2, and do not attempt to turn back - a turn at low altitude with one engine and a 2.1% gradient risks a stall or loss of control. Fly straight ahead, clean up, and climb to at least 400–500 ft before any turn. If the aircraft cannot maintain altitude, plan a forced landing ahead within the runway strip or clear area, and brief the cabin. The key difference from the 400 ft case is that at 100 ft there is no height to trade for a turn, so the only safe option is straight ahead and climb, or a controlled forced landing.