One Engine Inoperative (Simulated) (solely by Reference to Instruments) During Straight-and-Level Flight and Turns (AMEL, AMES)

Control, then configure, then diagnose (AFH 13-33, CA.X.C.S1–S5):

1. Stop the yaw with rudder and hold the attitude — "maintaining airplane control is still paramount."
2. Set the engine controls and reduce drag (gear and flaps up as applicable).
3. Identify by the control input you are holding, verify by retarding that throttle, simulate feathering the propeller — the evaluator then sets zero thrust.
4. Establish the best engine-inoperative airspeed and trim.
5. Verify the prescribed securing checklist, then work the cause.

Cruise altitude and speed buy you time for a diagnosis that a failure after takeoff never would.

Exactly the same way as in visual conditions — through the control inputs required to maintain straight flight, not the engine gauges (AFH 13-32). Under the hood the yaw shows up first as heading drift on the HSI or heading indicator and as a wing dropping on the attitude indicator, while your dead foot tells you which side quit. Gauge confirmation "may or may not be possible, depending upon the failure mode" — so it supports the diagnosis, it does not make it. The verify step by retarding the suspect throttle is never skipped (CA.X.C.R1).

Fixation. "Airplanes have been lost at altitude due to apparent fixation on the engine problem to the detriment of flying the airplane" (AFH 13-33). On instruments the trap is worse, because the checklist and the engine gauges pull your eyes out of the scan and there is no horizon to catch you. Set the airplane up, trim it, and keep the scan running between checklist items (CA.X.C.R4).

Because it buys back attention. Holding an untrimmed, sideslipping twin steady while scanning six instruments and reading a checklist is a workload trap, and the sideslip is simultaneously costing you the climb performance you may need to hold altitude. Set the bank at approximately 2° toward the operating engine with the ball one-third to one-half toward the good engine, then trim the pressure off (AFH 13-29). Useful detail for the oral: the zero-sideslip ball position for straight flight is also the correct position for turning flight (AFH 13-29).

Yes. Controllability and performance do not care about turn direction — "it is perfectly acceptable to make turns toward the failed engine" (AFH 13-34). What does matter is that turning flight reduces climb performance (AFH 13-32), so on one engine keep bank angles shallow, roll out promptly, and do not chain turns together while you are trying to hold altitude.

• Specified altitude ±100 feet, or minimum sink rate if applicable
• Airspeed ±10 knots
• Specified heading ±10° (CA.X.C.S8)

The "or minimum sink rate" clause applies when the airplane cannot hold altitude on one engine. It is not a general excuse — you have to fly VYSE precisely to claim it.

The drift down flown deliberately, plus a decision:

• VYSE: hold it to minimize the rate of altitude loss — the rate "is greatest immediately following the failure and decreases as the single-engine ceiling is approached" (AFH 13-34).
• Decision: assess the airplane's performance capability and decide an appropriate action to ensure a safe landing — nearest suitable airport, terrain and weather considered, ATC told (CA.X.C.S9).
• Fails the task: attempted flight contrary to the engine-inoperative operating limitations of the airplane (CA.X.C.S10).

Crossfeed becomes the tool: if prolonged single-engine flight is unavoidable, it makes the dead engine's trapped fuel available and lets you balance consumption, terminated prior to landing with the operating engine returned to its main tank (AFH 13-34). The operating engine runs at high power and burns from one side, so lateral imbalance builds and usable fuel may be trapped on the dead side — but if a suitable airport is close at hand, there's no need to consider crossfeed at all. Selector and boost pump procedures "differ greatly among multiengine airplanes," so this is AFM/POH knowledge, not technique (CA.X.C.R5).

It's producing high power, often for a long time, in a climb or level attitude that limits cooling airflow — so you watch:

• Cylinder head and oil temperatures
• Oil pressure
• Fuel flow and fuel quantity balance
• Cowl flaps, managed to control CHT

On the failed side, the one securing item that still affects performance is closing that engine's cowl flap (AFH 13-33). If the failure was catastrophic — heavy vibration, smoke, blistering paint, or large trails of oil — the engine is feathered and secured, you divert to the nearest suitable airport, and you declare an emergency with ATC for priority handling (AFH 13-34).

The ACS grades single-pilot or crew resource management explicitly (CA.X.C.S11):

• Declare and use ATC for vectors to the nearest suitable approach, terrain and obstruction clearance, and current weather.
• Offload the hand-flying to the autopilot if it is available and appropriate, so the scan and the checklist get your attention.
• Sequence the tasks: aviate, then navigate, then the securing checklist, then the diagnosis — the memory items are already done, and the printed items are accomplished "deliberately and without undue haste" (AFH 13-33).
• Brief passengers and set expectations before workload peaks on the approach.

By a smooth throttle reduction — the FAA recommends that all in-flight simulated engine failures below 3,000 feet AGL be introduced that way so the engine stays running and instantly available, and smooth movement avoids abusing the engine (AFH 13-35). Simulating a failure below VSSE "introduces a very high and unnecessary training risk," and pulling circuit breakers is not recommended for training. Once you retard the propeller control toward feather, the evaluator sets zero thrust and states clearly who is operating which engine — "any ambiguity as to who is operating what systems or controls increases the likelihood of an unintended outcome" (AFH 13-36, CA.X.C.S2).