Task IV.M
Power-Off 180° Accuracy Approach and Landing (ASEL, ASES)
To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with power-off 180° accuracy approach and landing.
Note: See Appendix 3: Aircraft, Equipment, and Operational Requirements & Limitations for information related to this Task.
References: AIM; FAA-H-8083-2, FAA-H-8083-3, FAA-H-8083-25; POH/AFM
Quick Review
Conversational Q&A — quiz yourself before the oral. This Task is new at the commercial certificate (ASEL, ASES) — there is no private equivalent, and it is the maneuver most commercial applicants spend the most time on.
Touch down at a proper pitch attitude within 200 feet beyond or on the specified point, with no side drift, and with the airplane's longitudinal axis aligned with and over the runway centerline or landing path (CA.IV.M.S8).
Read it as −0 / +200 feet: landing short of the point is outside the standard, landing more than 200 feet past it is outside the standard. There is no airspeed tolerance element on this Task — the ACS grades where and how the airplane arrives, not a number on the ASI.
Because on this Task the go-around can itself be the failure. ACS Appendix 3 states that initiating a go-around as a result of an applicant's inability to complete this Task within the tolerances specified in the skill elements is considered unsatisfactory.
Two important qualifiers in the same paragraph: runway safety concerns beyond the control of the applicant or evaluator that necessitate a go-around would not be considered unsatisfactory, and the applicant and evaluator must not sacrifice the safety of flight and force a landing to complete the Task. So: never force it — but understand that "I'll just go around if it's not working" is not a strategy here, it is the bust.
To instill the judgment and procedures necessary for accurately flying the airplane, without power, to a safe landing (AFH ch. 9). The underlying skill the maneuver builds is the ability to estimate the distance an airplane glides to a landing — which is the real basis of every power-off accuracy approach, and the difference between an engine failure that ends on a runway and one that does not.
Said commercially: you are being asked to prove you can put the airplane on a spot with no engine, which is what a passenger-carrying pilot owes the people in back.
Abreast of — opposite — the desired landing spot on a downwind leg flown parallel to the landing runway. When abeam the desired landing spot, close the throttle and maintain altitude while decelerating to the manufacturer's recommended glide speed, or 1.4 VSO in its absence. That point at which the throttle is closed is the downwind key position (AFH ch. 9).
Note the sequence: close the throttle first, then trade the excess speed for the time you need — you hold altitude while decelerating, then lower the nose to hold the glide speed and trim.
The starting altitude varies with the airplane but should usually not exceed 1,000 feet above the ground, except with large airplanes — greater accuracy in judgment and maneuvering is required at higher altitudes. There is a perceptual reason for that ceiling: with experience, altitudes up to approximately 1,000 feet can be estimated with fair accuracy, and above that the accuracy of height judgment decreases because ground features tend to merge (AFH ch. 9). Normal traffic pattern altitude is the usual answer.
Downwind key position through the turn: the manufacturer's recommended glide speed, or 1.4 VSO.
Once established on final in the landing configuration: adjust pitch and configuration for the proper descent angle and airspeed — 1.3 VSO (AFH ch. 9).
Trim at each stage. On a power-off approach the throttle is fixed at idle, so pitch attitude is what controls airspeed — and airspeed change is also what changes your glide angle.
The effect reverses depending on which side of best glide speed you're on. Above best glide speed: pitching down increases airspeed and steepens the descent; pitching up reduces airspeed and shallows it. Below best glide speed: pitching down increases airspeed and shallows the descent; pitching up reduces airspeed and greatly steepens it (AFH ch. 9).
So the fix depends on which side of best glide you are on: if the airspeed is too high, raise the nose; when the airspeed is too low, lower the nose. If pitch is raised too high the airplane settles rapidly from slow speed and insufficient lift — which is why the rule is absolute: never try to stretch a glide to reach the desired landing spot.
It is the 45° key position — the point on base at which the intended landing spot appears on a 45° angle from the airplane's nose (AFH ch. 9). Reaching it at the right altitude is what turns the 180° approach into a 90° approach you already know how to fly.
But do not fossilize it: the base key position should not be overemphasized nor considered a fixed point on the ground. Inexperienced pilots latch onto a tree or a crossroad at a certain altitude, which leaves them helpless the moment such objects are not there. Vary both altitude and geographic location as much as practical in training.
Late, and in stages — the governing rule is one sentence in the AFH: full flaps should be delayed until it is clear that adding them will not cause the landing to be short of the point (AFH ch. 9).
Practically:
- Initial flaps may be extended prior to the base key position if needed
- Flaps may be lowered gradually as needed on final, with pitch adjusted to hold the descent angle and airspeed
- If you are slightly high in the current configuration, you are assured of making the aiming point — that is the position you want to be in, because flaps and slips can spend altitude but nothing can create it
And the corollary error: never retract flaps to reach the landing spot.
No. While square patterns demonstrate good planning, they are not required and may not be appropriate for every approach. When conditions are not as expected you may dog-leg away from the runway on base, or dog-leg toward the runway on base (AFH ch. 9).
The other tools in the same list: S-turns, slips, early or late extension of flaps, reducing airspeed below best glide, or increasing airspeed slightly above best glide in a headwind — all in service of stabilizing the remaining approach so you reach the aiming point at an appropriate speed and touch down where planned. Position the base leg itself to conserve or dissipate altitude as needed.
Not the numbers. Selection of the runway numbers as the touchdown point does not provide a safety cushion in case of a mechanical problem or misjudgment — selecting a point farther down the runway establishes an increased safety margin (AFH ch. 9). With a −0 tolerance, any point you choose has a hard floor under it, so choose one with runway underneath.
And if the spot and the landing come into conflict on short final, the landing wins: full attention goes to making a good, safe landing rather than concentrating on the selected landing spot, because the approach angle and final approach airspeed already determined the probability of hitting it and late adjustments to those parameters are not appropriate. The AFH states the value judgment outright — it is always better to execute a good landing away from the spot than to make a poor landing precisely on or just past the spot.
No — decline it, and be able to say why. As PIC you have final authority to accept or decline any LAHSO clearance (PHAK ch. 14), and this Task is uniquely incompatible with one:
- Your tolerance is −0 / +200 feet from the specified point, and a LAHSO restriction imposes a hard stop beyond which no portion of the aircraft may extend. Accepting both means threading a box from two directions with the engine at idle.
- The AFH's own advice for spot selection cuts against it: selecting a point farther down the runway establishes an increased safety margin — exactly the direction LAHSO forbids.
- The go-around is the wrong escape here too. On this Task a go-around caused by your inability to hold tolerances is itself unsatisfactory (ACS Appendix 3), so you would be trading a bust for a bust.
If a LAHSO clearance is issued while you are set up for the maneuver, decline it or ask for a different runway before you close the throttle — not after.
It changes the geometry, not the technique. Determine the wind's strength and direction from the amount of crab needed to hold the desired ground track on the base leg — that also tells you when to lower flaps (AFH ch. 9). Then position the pattern to it: a strong headwind on final means a tighter, closer-in base and later flaps; a tailwind on downwind is the classic setup for overextending the downwind leg, which is a listed common error. In a headwind you may also increase airspeed slightly above best glide to preserve glide distance over the ground.
Deep Dive
Energy management: the maneuver in one sentence
The moment you close the throttle at the abeam point, the energy account is closed to deposits. Total mechanical energy — altitude plus airspeed (AFH ch. 4) — can now only be spent (drag) or redistributed between altitude and airspeed. From that instant the entire maneuver is a single question: do I have more energy than I need to reach the spot, or less?
More than enough is manageable — flaps, slip, S-turns, a wider base all convert surplus into drag. Less than enough is unrecoverable: there is no configuration change that adds energy, which is precisely why stretching the glide is the cardinal sin.
Fly it deliberately slightly energy-rich and spend the surplus late. That is the whole strategy behind "delay full flaps until it is clear they will not cause a landing short."
Because it converts judgment into a repeatable measurement. The basic procedure is closing the throttle at a given altitude and gliding to a key position, and starting with the same energy (airspeed and height) each time the throttle is closed makes the maneuver more predictable (AFH ch. 9). Same abeam point, same altitude, same speed, same configuration — then the only variable left is the wind, and you can read that off the crab angle.
The key position itself is not the objective — it is merely a convenient point in the air from which to judge what to do so the landing occurs at or just beyond the desired point. From the key position, constantly evaluate the situation.
Slips: the commercial application
You demonstrated forward slip mechanics on the private checkride. Here it stops being a maneuver and becomes an energy tool inside another maneuver — and the ACS calls out its hazards explicitly (CA.IV.M.R7).
A slip produces a marked increase in drag and, because the airplane is banked, a reduced vertical component of lift — so it descends rapidly without an increase in airspeed (AFH ch. 9). In a forward slip, the amount of slip and therefore the sink rate is determined by the bank angle: steeper bank, steeper descent, with power at idle and airspeed controlled by elevator.
The limit is rudder travel. In most light airplanes you reach a point where full rudder is required to maintain heading even though the ailerons could steepen the bank further — that is the practical slip limit, because any additional bank would start a turn. Beyond it, lowering the nose increases sink rate but also airspeed; the higher airspeed increases rudder effectiveness and permits a steeper slip. Raise the nose and rudder effectiveness decreases, so bank angle should be reduced.
Because it is reversible without penalty. In an engine-out situation a pilot can initiate a descent using a forward slip much more quickly than by deploying flaps, and to reduce the descent can remove the slip without penalty — whereas retracting flaps on an approach could lead to an unwanted loss of altitude (AFH ch. 9). Even at full rudder deflection you can still adjust left and right of the intended ground track by varying aileron.
That asymmetry is the practical reason the AFH tells you to hold full flaps until they are clearly safe: flaps are a one-way commitment, and a slip is not.
Lower the upwind wing — slipping into the crosswind makes it easier to remain on the original flightpath (AFH ch. 9), and it sets you up for the transition the ACS requires: correlate the crosswind with the direction of forward slip and transition to a side slip before touchdown (CA.IV.M.S7).
The distinction that matters at touchdown: in a side slip the longitudinal axis stays parallel to the original flightpath and the bank kills the drift — that is the crosswind landing tool. In a forward slip the nose is yawed off the flightpath for drag. The standard requires the longitudinal axis aligned with and over the runway centerline at touchdown (CA.IV.M.S8), so the forward slip must be gone and the sideslip established before the wheels arrive. A slip in the same direction as the crosswind and a late transition to the sideslip are both listed common errors.
- Fuel flowage: some airplanes limit slips in duration or by fuel quantity, to preclude fuel starvation caused when fuel is forced to one side of a tank in uncoordinated flight (AFH ch. 9). In a real engine-out emergency the time or fuel limitation is irrelevant — unless a prolonged slip caused the engine problem in the first place.
- Slips with flaps extended: for aerodynamic reasons there may also be recommendations or limitations related to slips with flaps extended — consult the AFM/POH for your airplane (AFH ch. 9).
- Airspeed control: because of pitot and static vent location, airspeed indicators in some airplanes may have considerable error in a slip. Recognize a properly performed slip by the attitude of the airplane, the sound of the airflow, and the feel of the controls — not by the needle. Reacting to erroneous airspeed indications is a listed common error.
On the low-altitude-maneuvering question (CA.IV.M.R5): a slip is cross-controlled, but it is not the killer. Unlike skids, if an airplane in a slip is made to stall it displays very little of the yawing tendency that causes a skidding stall to develop into a spin — it may do little more than roll toward wings level. The lethal cousin is the skidding base-to-final turn, the opposite input set. Discontinuing the slip has its own trap, though: level the wings and release rudder pressure simultaneously while readjusting pitch to the normal glide attitude. Release the rudder abruptly and the nose swings into line too quickly and the airplane acquires excess speed — on a −0/+200 approach, excess speed is float you did not budget for.
Common errors
Nine, and most checkride busts are on this list (AFH ch. 9):
- Downwind leg too far from the runway
- Overextension of the downwind leg resulting from a tailwind
- Inadequate compensation for wind drift on base
- Skidding turns in an effort to increase gliding distance
- Failure to lower the landing gear in retractable-gear airplanes
- Attempting to "stretch" the glide during an undershoot
- Premature flap or landing gear extension
- Use of throttle to increase the glide instead of merely clearing the engine
- Forcing the airplane onto the runway to avoid overshooting the designated spot
Numbers 4, 6, and 9 are the dangerous ones; 1, 2, and 7 are the ones that produce a short landing and a −0 bust.
The ACS addresses it in Appendix 3: certain single-engine turboprop airplanes experience an excessive rate of descent if the power is set to flight idle, and in some cases the manufacturer's checklist calls for feathering the propeller during a power-off glide. During training and certification the propeller is not feathered — instead, where the checklist calls for feathering in a power-off situation, the pilot should set sufficient power to provide the performance that would be expected with the propeller feathered (ACS Appendix 3; AFH ch. 9).
Know this even in a fixed-pitch trainer: it is the kind of "why is that note in the ACS" question that separates a memorized maneuver from an understood one.
Official ACS elementsreference
Knowledge4 elements
The applicant demonstrates understanding of:
CA.IV.M.K1A stabilized approach, including energy management concepts.CA.IV.M.K2Effects of atmospheric conditions, including wind, on approach and landing.CA.IV.M.K3Wind correction techniques on approach and landing.CA.IV.M.K4Purpose of power-off accuracy approach.
Risk Management14 elements
The applicant is able to identify, assess, and mitigate risk associated with:
CA.IV.M.R1Selection of runway/landing surface, approach path, and touchdown area based on pilot capability, aircraft performance and limitations, available distance, and wind.CA.IV.M.R2Effects of:CA.IV.M.R2aCrosswindCA.IV.M.R2bWindshearCA.IV.M.R2cTailwindCA.IV.M.R2dWake turbulenceCA.IV.M.R2eLanding surface/conditionCA.IV.M.R3Planning for:CA.IV.M.R3aRejected landing and go-aroundCA.IV.M.R3bLand and hold short operations (LAHSO)CA.IV.M.R4Collision hazards.CA.IV.M.R5Low altitude maneuvering, including stall, spin, or controlled flight into terrain (CFIT).CA.IV.M.R6Distractions, task prioritization, loss of situational awareness, or disorientation.CA.IV.M.R7Forward slip operations, including fuel flowage, tail stalls with flaps, and airspeed control.
Skills8 elements
The applicant exhibits the skill to:
CA.IV.M.S1Complete the appropriate checklist(s).CA.IV.M.S2Make radio calls as appropriate.CA.IV.M.S3Plan and follow a flightpath to the selected landing area considering altitude, wind, terrain, and obstructions.CA.IV.M.S4Select the most suitable touchdown point based on wind, landing surface, obstructions, and aircraft limitations.CA.IV.M.S5Position airplane on downwind leg, parallel to landing runway.CA.IV.M.S6Correctly configure the airplane.CA.IV.M.S7As necessary, correlate crosswind with direction of forward slip and transition to side slip before touchdown.CA.IV.M.S8Touch down at a proper pitch attitude, within 200 feet beyond or on the specified point with no side drift and with the airplane’s longitudinal axis aligned with and over the runway centerline or landing path, as applicable.