Maneuvering with One Engine Inoperative (AMEL, AMES)

All of them. The Area XIII note in the CFI ACS reads: "The evaluator must assess all Tasks." There is no menu here — you will teach Maneuvering with One Engine Inoperative (XIII.A), the VMC Demonstration (XIII.B), and the Demonstration of Effects of Various Airspeeds and Configurations (XIII.C).

Area XIII applies to AMEL and AMES applicants only. Plan the flight so all three fit in one OEI block at altitude, because every one of them has to be completed no lower than 3,000 feet AGL or the manufacturer's recommended altitude, whichever is higher (ACS Appendix 2, Multiengine Considerations).

Four words: "and provide effective instruction." The commercial applicant flies the engine-out profile. You must fly it and simultaneously teach it — the ACS Skills preamble for these Tasks reads "The applicant demonstrates and simultaneously explains how to."

So every element has four layers you owe the evaluator:

1. The aerodynamics one level deeper than the student needs.
2. The teaching — preflight brief, demonstration narration, error naming.
3. The risk management of instructing — your floors, your triggers for taking the controls.
4. The completion standard the student is being trained toward (AI.XIII.A.S7).

Teach it as four separate, spoken steps so the student never blends them:

• Identify — "primarily through the control inputs required to maintain straight flight, not the engine gauges." Confirmation on the gauges "may or may not be possible, depending upon the failure mode" (AFH 13-32). The memory aid is dead foot—dead engine: rudder pressure is on the side of the operating engine (AFH 13-33).
• Verify — retard the throttle of the engine you believe failed. No change in performance is the verification (AFH 13-32).
• Feather — the corresponding propeller control fully aft (AFH 13-32).
• Secure — feathering "only alters blade angle and stops engine rotation." Securing is fuel off (mixture, electric boost pump, fuel selector), ignition, alternator/generator, and cowl flaps closed — plus the pressurization air bleed and any firewall shutoff valve if installed (AFH 13-6).

Make the student say all four out loud. Silent hands are how the wrong engine gets shut down.

No — and this is where a checklist-only student gets hurt. "Completely securing a failed engine may not be necessary or even desirable depending upon the failure mode, altitude, and time available" (AFH 13-6).

Give the student the reasoning, not the rule:

• The fuel, ignition, and alternator/generator switch positions of the failed engine have "no effect on aircraft performance" — securing them buys nothing aerodynamically (AFH 13-6).
• Meanwhile "the pilot might manipulate the incorrect switch under conditions of haste or pressure" (AFH 13-6) — and the switches that matter are the good engine's.
• So the drag items (feather, gear, flaps) are time-critical; the securing items are not.

Teaching rule: feather now, secure deliberately — off the printed checklist, touching and confirming each control before moving it, "deliberately and without undue haste" unless a fire is suspected (AFH 13-32).

The AFH breaks the adequate-performance takeoff scenario into control, configuration, climb, and checklist (AFH 13-31 to 13-32), and that ordering is the whole lesson:

• Control — "Maintaining directional control with prompt and often aggressive rudder application and STOPPING THE YAW is critical." Keep airspeed above VMC. If the yaw cannot be controlled with full rudder, reducing thrust on the operative engine is the only alternative. Rudder first, then aileron: "At least 5° and a maximum of 10° of bank toward the operative engine should be used initially to stop the yaw and maintain directional control. This initial bank input is held only momentarily, just long enough to establish or ensure directional control" (AFH 13-31).
• Configuration — memory items: VYSE, takeoff power, flaps and gear up, identify/verify/feather (AFH 13-31).
• Climb — once directional control is established, reduce the bank to the zero-sideslip value and hold VYSE with pitch. Turning costs climb, so climb "straight ahead or with shallow turns to avoid obstacles to an altitude of at least 400 feet AGL before attempting a return to the airport" (AFH 13-32).
• Checklist — the printed copy, then securing, deliberately and without haste (AFH 13-32).

Narrate cause and effect, one item at a time, and keep the airplane doing exactly one new thing at a time (AIH 9-5, Demonstration Phase):

1. "Clearing turns, and I'm noting our altitude — everything today finishes above 3,000 AGL."
2. "Throttle coming back smoothly. Watch the yaw — right foot in before the nose moves ten degrees, then five degrees of bank into the good engine just long enough to pin the heading."
3. "Airspeed to blue line. Pitch controls the speed, and the pitch attitude is lower than VY."
4. "Dead foot, right foot is loaded, so the left engine is dead. Verify — throttle back. No change."
5. "Prop control aft. Feathering. Now gear up, flaps up — I'm buying back drag."
6. "Yaw is stopped, so the bank comes back to about two degrees, ball a third to a half out toward the good engine. That's zero sideslip."

If the demonstration deviates from what you explained, acknowledge and explain the deviation immediately (AIH 9-5).

With both engines running, a centered ball means zero sideslip and minimum drag. With an engine out, asymmetric thrust breaks that relationship, and there is no flight deck instrument that directly indicates zero sideslip (AFH 13-27).

Two controls oppose the asymmetric thrust — rudder yaw, and the horizontal component of lift from bank. "Used individually, neither is correct. Used together in the proper combination, zero sideslip and best climb performance are achieved" (AFH 13-27 to 13-28).

The target, absent AFM/POH guidance: a bank of about 2° toward the operating engine (models vary from 1.5° to 2.5°), with the ball one-third to one-half a ball width toward the operating engine (AFH 13-29). Memory aid: raise the dead (AFH 13-33).

Because the red radial line is one number produced under one certification condition, and every one of those conditions is changing while your student maneuvers. "A knowledgeable and competent multiengine pilot understands that VMC is not a fixed airspeed under all conditions" (AFH 13-23).

What moves it (AFH 13-24 to 13-25):

• Power on the operating engine — more power, higher VMC. Normally aspirated: highest at sea level, decreasing with altitude. Turbocharged: constant to the critical altitude, then decreasing.
• Drag on the inoperative engine — highest with the propeller windmilling; feathering lowers VMC.
• Aft CG — shortens the rudder's moment arm, raising VMC.
• Lighter weight — "VMC increases as weight is reduced."
• Gear retracted — extended gear aids directional stability, so retraction raises VMC.
• Less bank toward the good engine — the largest single factor (full treatment in Task XIII.B).

The instructor's takeaway: the red line is a best case. Your student's actual loss-of-control speed on a given day is usually higher, which is why the working floor you enforce is VYSE, not VMC.

Because the climb margin you are fighting for is tiny. Loss of one engine is a loss of 50 percent of power but reduces climb performance 80 to 90 percent (AFH 13-1) — in the handbook's hypothetical twin, 225 excess thrust horsepower falls to 25 (AFH 13-3).

Priorities:

• Feather the propeller. At small blade angles a propeller windmilling at high rpm "can produce parasite drag as great as the parasite drag of the entire airframe" (AFH 13-3).
• Landing gear up — and note that with the gear selector still DOWN, continued takeoff is not recommended (AFH 13-33).
• Flaps up — "the use of wing flaps for takeoff virtually eliminates the likelihood of a single-engine climb until the flaps are retracted" (AFH 13-33).
• Zero sideslip — any other attitude increases drag (AFH 13-29).

Most multiengine constant-speed propellers are full feathering, counterweighted, oil-pressure-to-decrease-pitch designs — the opposite of the single-engine propellers your student knows. "The only thing that keeps these propellers from feathering is a constant supply of high-pressure engine oil," which is exactly what lets them feather after a loss of oil pressure or a governor failure (AFH 13-5).

Bring the propeller control fully aft and oil pressure dumps; counterweights, plus a spring or high-pressure air in the dome, drive the blades to feather. The entire process may take up to 10 seconds (AFH 13-5). Below approximately 800 rpm, anti-feathering lock pins move into place and block feathering — so feather before rpm decays (AFH 13-7).

Per AFM/POH, but the general sequence is (AFH 13-6):

1. Ignition on, throttle at low idle, mixture rich, propeller control to a high rpm position.
2. Engage the starter. The engine windmills, starts, and runs as oil pressure drives the blades out of feather.
3. Immediately reduce rpm as it starts and give it several minutes to warm — monitor cylinder head and oil temperatures.

An unfeathering accumulator stores oil under pressure so the propeller can be brought out of feather without the starter; if it fails, use the starter (AFH 13-6).

Training limits: actual feathering is done at a position and altitude from which a safe landing on an established airport is possible, with unfeathering and restart planned to be complete no lower than 3,000 feet AGL (AFH 13-36, ACS Appendix 2).

Brief it first — "surprising a multiengine learner with an emergency without a thorough briefing beforehand creates a hazardous condition," and stall-spin accidents in training for emergencies rival the number from actual emergencies (AFH 13-35).

Then the mechanics:

• Never below VSSE. Simulating a failure below VSSE "introduces a very high and unnecessary training risk" (AFH 13-35).
• All in-flight simulated failures below 3,000 feet AGL are introduced with a smooth throttle reduction, so the engine keeps running and is instantly available (AFH 13-35).
• Do not pull circuit breakers — not recommended, and it can lead to a gear-up landing (AFH 13-35).
• Low-altitude simulated failures happen no lower than 400 feet AGL, and only after the student has mastered the procedures at altitude (AFH 13-36, ACS Appendix 2).

Take the failed engine explicitly. "Assuming zero thrust will be set, the instructor promptly moves the propeller control forward and sets the appropriate manifold pressure and rpm. It is vital that the learner be kept informed of the instructor's intentions" (AFH 13-36).

The handbook even scripts it: "I have the right engine; you have the left. I have set zero thrust and the right engine is simulated feathered." Ambiguity about who is operating what "increases the likelihood of an unintended outcome" (AFH 13-36).

Then care for the "failed" engine as the student cares for the good one — cowl flap closed, mixture leaned, clear it occasionally, and avoid a high power application right after a long cool-down at zero thrust (AFH 13-36).

Name them in the airplane, one at a time:

• Slow or timid rudder — the yaw is allowed to develop. "Prompt and often aggressive rudder application" is the standard (AFH 13-31). Correction: "Stop the yaw first, then think."
• Correcting roll with aileron before rudder — "increases drag and adverse yaw and further degrades directional control" (AFH 13-31).
• Wings level, ball centered — moderate sideslip, degraded climb, and VMC significantly higher than published (AFH 13-28).
• Holding the initial bank — the 5 to 10° that stopped the yaw is "held only momentarily"; climb suffers beyond about 2 to 3°, so it must come back to the zero-sideslip bank as soon as control is established (AFH 13-31).
• Identifying off the gauges instead of the controls (AFH 13-32).
• Skipping verify — the path to feathering a good engine.
• Fixation on the engine to the detriment of flying — airplanes have been lost at altitude doing exactly this (AFH 13-34).
• Failure to trim, leaving high rudder forces the student cannot hold.

Altitude ±100 feet (or minimum sink rate if applicable), airspeed ±10 knots, and selected headings ±10°.

Teach the "or minimum sink rate" clause deliberately: in most training twins at most weights and density altitudes, holding altitude on one engine is not a given. Above the single-engine absolute ceiling the airplane "slowly loses altitude," and the pilot maintains VYSE to minimize the rate of altitude loss — the drift-down rate is greatest right after the failure and decreases as the single-engine ceiling is approached (AFH 13-34).

A student who mistakes the ±100 feet for a promise of level flight will pull. That is the accident.

Set them in the brief and enforce them without negotiation:

• Floor — all work finishes at or above 3,000 feet AGL (ACS Appendix 2).
• Speed floor — VYSE. If the airspeed decays toward VMC and the student does not lower the nose, that's the take.
• Yaw — if full rudder will not hold it, reduce power on the operating engine; that is the only alternative (AFH 13-31).
• Any stall symptom with asymmetric thrust — reduce AOA immediately. A stall under asymmetric power makes a spin entry likely, and the airplane departs in the direction of the idle engine, not the applied rudder (AFH 13-26).
• Collision avoidance is yours (AI.XIII.A.R2). Clearing turns before every setup, and once the failure is introduced the student is head-down on gauges and levers — nobody is looking outside unless you are. Say who has the scan in the brief, and keep calling traffic through the demonstration.

Take the controls; don't share them. "Anxious learners can be incredibly strong and usually exhibit reactions inappropriate to the situation" (AIH 9-9). Announce it: "I have the flight controls."

Climb is a function of thrust horsepower in excess of that required for level flight — not total horsepower (AFH 13-1).

Take the handbook's hypothetical twin: each engine produces 200 thrust horsepower, and level flight requires 175.

Both engines: 400 available − 175 required = 225 available for climb.

One engine: 200 available − 175 required = 25 available for climb.

You lost 50 percent of the power and roughly 89 percent of the climb (AFH 13-3). And that arithmetic assumes the propeller is already feathered and the airplane is clean — before that, the required side of the equation is larger too.

Very possibly none. For reciprocating multiengine airplanes certificated under the historical part 23 rules (AFH 13-3):

More than 6,000 lb maximum weight and/or VSO more than 61 knots: single-engine rate of climb at 5,000 feet MSL must be at least 0.027 × VSO²; for airplanes type certificated February 4, 1991 or later, a 1.5 percent climb gradient.

6,000 lb or less and VSO 61 knots or less: the single-engine rate of climb at 5,000 feet MSL "must simply be determined. The rate of climb could be a negative number. There is no requirement for a single-engine positive rate of climb at 5,000 feet or any other altitude."

Most light twins used for training fall in the second bucket. Say that out loud to your student once, early.

Teach it as a pre-briefed decision point, not an in-the-moment judgment. "An emergency contingency plan and safety brief should be clearly understood well before the takeoff roll commences" (AFH 13-30).

The AFH's three scenarios (AFH 13-30 to 13-32):

1. Gear still down — close both throttles, keep the nose straight, land on the remaining runway or overrun. "There are really no other practical options."
2. Gear up, climb performance inadequate — land on whatever essentially lies ahead, or continue in a descent at VYSE. "Remaining airborne and bleeding off airspeed in a futile attempt to maintain altitude is almost invariably fatal."
3. Gear up, climb performance adequate — control, configuration, climb, checklist.

The planning rule: continuing "probably does not exist as an option unless the published single-engine rate of climb is at least 100 to 200 fpm," and turbulence, gusts, wear, or sloppy technique "can easily negate even a 200 fpm rate of climb" (AFH 13-12).

The mechanism — the psychological reluctance to feather a propeller that is still turning — and the AFH's prescribed cure are covered under Task XII.F, and the demonstration itself is Task XIII.C.

What this Task contributes is when the hesitation actually bites, because it isn't during a feathering lesson. It's here, on an engine failure in flight, where the student has to identify, verify, and decide under time pressure with a propeller still spinning in the corner of their eye. A student who has only feathered on request, announced and expected, has never met the hesitation at all.

So build the exposure in deliberately:

• Fail the engine without announcing it once the student is competent at the announced version, and watch the gap between "identify" and "feather." That gap is the thing being trained
• Time it out loud in the debrief. Not as criticism — as data. "You had it identified in four seconds and feathered at twenty-two" makes the hesitation visible in a way that no amount of telling does
• Don't let a correct verify substitute for a decision. Students learn to run the flow beautifully and stop at the prop control. Name that specifically when you see it

The reluctance is a trained-out problem, not a briefed-out one.

Not reflexively. "If there is a performance loss when the throttle of the affected engine is retarded, some power is still available. In this case, the pilot may consider allowing the engine to run until the airplane reaches a safe altitude and airspeed for single-engine flight." Shutting down an engine still producing partial power "may increase risk for an accident" (AFH 13-33).

At altitude, the diagnosis is the lesson (AI.XIII.A.S4). Cruise airspeed and altitude "may permit time for a possible diagnosis and remedy." Many power losses are fuel starvation — another tank, carburetor heat or alternate air, a different mixture, boost pump for vapor, or running on one magneto (AFH 13-34).

The reversal: heavy vibration, smoke, blistering paint, or large trails of oil is a critical situation — feather, secure, divert, declare (AFH 13-34).