ME.7
Single-Engine Approach and Landing
Plan and fly a visual approach and landing with one engine inoperative, including configuration timing and why a single-engine go-around is usually not available once committed to land.
References: FAA-H-8083-3 (AFH ch. 13); FAA-H-8083-15; POH/AFM
Quick Review
Conversational Q&A — quiz yourself before the oral.
Structurally, it doesn't — the approach and landing with OEI is essentially the same as a two-engine approach and landing. The traffic pattern should be flown at similar altitudes, airspeeds, and key positions (AFH ch. 13).
The differences are the reduced power available and the fact that the remaining thrust is asymmetrical. A higher-than-normal power setting is necessary on the operative engine.
Yes. The direction of the traffic pattern, and therefore the turns, is of no consequence as far as airplane controllability and performance are concerned — turns toward the failed engine are perfectly acceptable (AFH ch. 13).
Don't distort your pattern to avoid it — flying an awkward pattern to dodge a non-problem creates a real one.
With adequate airspeed and performance, on the downwind leg — confirmed DOWN no later than abeam the intended point of landing (AFH ch. 13).
Performance permitting, an initial flap extension (typically 10 degrees) and a descent from pattern altitude can also begin on downwind. Airspeed should be no slower than VYSE.
Performance decides (AFH ch. 13):
- If performance is adequate — flaps may go to an intermediate setting, typically 25 degrees
- If performance is inadequate — as measured by decay in airspeed or high sink rate — delay further flap extension until closer to the runway
VYSE is still the minimum airspeed to maintain.
Maintain VYSE until the landing is assured, then slow to 1.3 VSO or the AFM/POH recommended speed (AFH ch. 13).
The final flap setting may be delayed until the landing is assured, or the airplane may be landed with partial flaps.
A normal 3-degree glidepath to a landing is desirable. Use VASI or other vertical path lighting aids if available. Slightly steeper approaches may be acceptable (AFH ch. 13).
Avoid a long, flat, low approach and large, sudden power applications or reductions.
Because most light twins do not have the performance to climb on one engine with landing gear and flaps extended (AFH ch. 13).
Considerable altitude is lost while maintaining VYSE and retracting landing gear and flaps — losses of 500 feet or more are not unusual. And if the gear was lowered with an alternate means of extension, retraction may not be possible, virtually negating any climb capability.
Once the airplane is on final approach with landing gear and flaps extended, it is committed to land — on the intended runway, on another runway, a taxiway, or the grassy infield (AFH ch. 13).
That's not a failure of technique; it's the airplane's honest performance. Plan the approach knowing the go-around option is spent.
A rudder trim change as the power of the operating engine is reduced to idle just prior to touchdown (AFH ch. 13).
The airplane should remain in trim throughout the approach — but be ready for that shift at the worst possible moment, close to the ground.
Some pilots reset the rudder trim to neutral on final and compensate for yaw by holding rudder pressure for the remainder of the approach (AFH ch. 13).
This eliminates the rudder trim change close to the ground as the throttle is closed in the round out, and removes the need to grope for the rudder trim and manipulate it during final — which many pilots find highly distracting. Use the AFM/POH recommendation or personal preference.
Because there is drag from only one windmilling propeller instead of two (AFH ch. 13).
Precise airspeed control is therefore essential, especially when landing on a short, wet, or slippery surface.
- Minimal float — higher wing loading plus drag from two windmilling propellers
- Full stall landings are generally undesirable in twins. Hold the airplane off as with a high-performance single, allowing touchdown of the main wheels prior to a full stall
- The pattern and approach are flown at somewhat higher indicated airspeeds — start the before-landing checklist early
- Residual power is gradually reduced to idle in the round out
(AFH ch. 13)
Use the manufacturer's recommended speed with power. If no recommended speed is furnished, the speed should be no slower than VYSE until short final with the landing assured — but in no case less than VMC (AFH ch. 13).
Delaying full flap extension to short final with the landing assured is an acceptable technique with appropriate experience and familiarity with the airplane.
To the greatest extent practical, on final approach and within 500 feet AGL, the airplane should be (AFH ch. 13):
- On speed
- In trim
- Configured for landing
- Tracking the extended centerline of the runway
- Established in a constant angle of descent toward an aim point in the touchdown zone
Absent unusual conditions, only minor corrections should be required from there to round out and touchdown.
Deep Dive
Planning the descent
Because of higher cruising speed and frequently higher altitude. A hurried, last-minute descent with power at or near idle is inefficient and can cause excessive engine cooling, and may cause passenger discomfort, particularly if unpressurized (AFH ch. 13).
Rule of thumb: if terrain and passenger conditions permit, plan a maximum 500 fpm rate of descent. Pressurized airplanes can plan higher rates if desired.
Some airplanes require a minimum EGT, minimum power setting, or cylinder head temperature in the descent. Combinations of very low manifold pressure and high rpm are strongly discouraged by engine manufacturers — if a higher descent rate is needed, consider extending partial flaps or lowering the landing gear before retarding power excessively.
The two-engine go-around, for contrast
Knowing the normal go-around sharpens why the single-engine version usually isn't available.
Sequentially (AFH ch. 13):
- Throttles to takeoff power, pitch adjusted to arrest the sink rate
- With adequate airspeed, establish a climb pitch attitude
- Initial target airspeed VY, or VX if obstructions are present
- With sufficient airspeed, retract flaps from full to an intermediate position
- Retract the landing gear when there is a positive rate of climb and no chance of runway contact
- Retract the remaining flaps
Two reasons (AFH ch. 13): on most airplanes, full flaps produce more drag than the extended landing gear, and the airplane tends to settle somewhat with flap retraction — so the gear should already be down in the event of an inadvertent, momentary touchdown.
- If the airplane was in trim for the landing approach, it soon requires a great deal of forward elevator pressure as it accelerates away in a climb. Apply forward pressure to hold pitch attitude and begin trimming immediately
- Many twins have a landing gear retraction speed significantly less than the extension speed — don't exceed it
- If you return for a landing, re-accomplish the entire before-landing checklist. An interruption to habit patterns such as a go-around is a classic scenario for a subsequent gear-up landing (AFH ch. 13)
The initial pitch-up must be tempered by the necessity to maintain adequate flying speed throughout the maneuver — for example, a go-around from the landing round out, recovery from a bad bounce, or one initiated because of an inadvertent approach to a stall.
The first priority is always to maintain control and obtain adequate flying speed. A few moments of level or near-level flight may be required as the airplane accelerates to climb speed (AFH ch. 13).
Crosswind and short-field cases
The principles are no different from a single. The two primary methods — crab and wing-low — are typically used in conjunction (AFH ch. 13):
- On rolling out onto final, establish the crab angle to track the extended centerline
- Prior to touchdown, transition to a sideslip with the upwind wing lowered and opposite rudder applied to prevent a turn
- Touch down on the upwind main gear first, then the downwind, then the nose gear
- Follow through with increasing aileron into the wind until full deflection is reached
Prior to touchdown, the longitudinal axis must be aligned with the runway centerline to avoid landing gear side loads. Twins are often easier than singles in a crosswind, due to the higher approach and landing speed.
When the upwind wing is lowered, power on the upwind engine is increased to prevent the airplane from turning — the asymmetrical thrust produces a yawing moment little different from the rudder's (AFH ch. 13).
It is completely acceptable, but most pilots feel they can react to changing wind conditions quicker with rudder and aileron than throttle movement — especially with turbocharged engines, where throttle response may lag momentarily. Practice it with an instructor before attempting it alone.
Some multiengine airplanes have AFM/POH limitations against slips in excess of a certain time period — 30 seconds, for example. This prevents engine power loss from fuel starvation as fuel in the lowered wing's tank flows toward the wingtip, away from the pickup point. Observe the limit if using the wing-low method (AFH ch. 13).
The emphasis is on (AFH ch. 13):
- Configuration — full flaps
- A stabilized approach with a constant angle of descent
- Precise airspeed control
Full flaps provide the steepest approach angle. Plan so that no drastic power reductions are required after obstacles are cleared — propeller blast blows over the wings providing lift as well as thrust, so reducing power significantly just after obstacle clearance usually results in a sudden, high sink rate that may lead to a hard landing. Smoothly reduce power to idle in the round out.
Some AFM/POHs recommend a slightly slower than normal approach speed; if none is published, use the normal approach speed.
Braking and rollout
Under favorable wind and runway conditions, the nose-wheel can be held off for best aerodynamic braking, and continued elevator back pressure greatly assists the wheel brakes even after the nose-wheel is gently lowered (AFH ch. 13).
But it's undesirable to rely solely on aerodynamic braking if:
- Runway length is critical
- There's a strong crosswind
- The surface is contaminated with water, ice, or snow
Place the full weight of the airplane on the wheels as soon as practicable — the wheel brakes are more effective than aerodynamic braking alone.
Generally no. Flap retraction on the rollout is discouraged unless there is a clear operational need, and it should not be accomplished as routine with each landing (AFH ch. 13).
Short field, high winds, or strong crosswinds are just about the only situations where it should be considered. When there is an operational need, do it deliberately, with the flap handle positively identified before it is moved — there is always a significant risk of retracting the landing gear instead of the wing flaps.
Ordinarily, make no attempt to retract flaps or perform other checklist duties until the airplane is stopped clear of the active runway. Never reach out indiscriminately for any switch or control on rollout.