Private pilot · ACS PA.X.C · Instructor lesson plan

One Engine Inoperative by Reference to Instruments

Student pack: Train: One Engine Inoperative by Reference to Instruments · Full lesson: Prepare guide

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1 · Objective

By the end of this lesson your student can explain one engine inoperative by reference to instruments in their own words, apply it in a realistic situation, and fly it to the ACS standard for PA.X.C.

Why it matters for safety: An engine failure in instrument conditions doubles the workload: no outside horizon, a yawing airplane, and decisions about altitude, weather and approaches. A pilot who flies attitude and rudder first, then works the flow, keeps control.

2 · Assign before the lesson

Pre-work: the free Train pack, One Engine Inoperative by Reference to Instruments. Handle an engine failure in the clouds: control by attitude, identify on the instruments, and decide where to land.

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Pack: pilotprep.pro/train/ppl/one-engine-inoperative-by-reference-to-instruments · Full lesson: pilotprep.pro/prepare/ppl/one-engine-inoperative-by-reference-to-instruments

3 · Teach sequence

Key points to land

On instruments, the first sign is yaw: the heading turns and the ball (or slip indicator) moves. Hold the attitude and add rudder.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Instrument Flying Handbook (FAA-H-8083-15B))
The flow, in order: control and attitude; power forward; drag off; identify ("dead foot, dead engine"); verify; feather; secure by the checklist; then troubleshoot.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Private Pilot ACS (FAA-S-ACS-6C), PA.X.C.S2, S6)
Verify by slowly closing the suspected engine's throttle: no change is the confirmation. Manifold pressure, fuel flow and EGT are supporting evidence only.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Zero sideslip on instruments: bank about 2-3° toward the operating engine on the attitude indicator, with the ball one-third to one-half out toward it, not centered.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Private Pilot ACS (FAA-S-ACS-6C), PA.X.C.S4)
If you can't hold the yaw or roll with full rudder, reduce power on the operating engine and lower the nose until control returns. Blue line is for performance; VMC is the control limit.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Private pilot standard: altitude ±100 feet (or minimum sink), airspeed ±10 knots, heading ±10°.(Private Pilot ACS (FAA-S-ACS-6C), PA.X.C.S8)
Decide early: the nearest airport with an approach you can fly on one engine, and tell ATC.(Private Pilot ACS (FAA-S-ACS-6C), PA.X.C.S9)

Procedures on instruments

Yaw shows as a heading change and a displaced ball; roll follows. Hold the wings with aileron and stop the yaw with rudder.(Instrument Flying Handbook (FAA-H-8083-15B))
Set blue line, then the flow: power forward, drag off, identify (dead foot), verify (close the throttle: no change), feather, secure by the checklist; the engine gauges support, but don't replace, the verify step.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Then zero sideslip and trim: about 2-3° of bank toward the operating engine on the attitude indicator, the ball one-third to one-half out toward it.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Turns: a failure in a turn is flown the same way, roll toward wings level or the zero-sideslip bank first. Turn in either direction at standard rate or less, keep the zero-sideslip offset through the turn, and lead the rollout.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Instrument Flying Handbook (FAA-H-8083-15B))
Once secured, troubleshoot by the checklist and judge whether a restart is wise; after a fire, a mechanical failure or an unknown cause, keep it secured.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes; Your airplane's POH/AFM)
If you can't stop the yaw with full rudder, reduce power on the operating engine and lower the nose; then build back to blue line.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)

Performance and fuel

Losing one engine costs half the power but 80-90% of the climb performance. Many light twins can't climb on one engine, and some can't hold altitude, at gross weight on a hot day or at a high field.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Single-engine service ceiling: where the airplane climbs only 50 feet per minute at VYSE. Absolute ceiling: where it can't climb at all. Above the absolute ceiling it drifts down at VYSE and levels off there; between the two it still climbs, just slowly.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
If you can't hold altitude, fly blue line for the least sink and ask ATC for a lower altitude, at or above the minimum en route or vectoring altitude where you can.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Fuel: crossfeed is an emergency procedure, used only as the POH says, never for takeoff or landing, and never toward a side with a fire or a leak. Plan the diversion at single-engine fuel flow.(Your airplane's POH/AFM)

Low altitude and attention

Hold blue line; don't let the airspeed decay trying to climb. VXSE is used only to clear an obstacle after takeoff, then accelerate to VYSE. The hard floor with asymmetric power is VMC (VSSE for intentional failures); a stall there can roll into a spin.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes)
Tell ATC: declare an emergency when warranted, state that you are on one engine, and ask for the vectors, altitudes and runway you need.(Aeronautical Information Manual (AIM))
A failure is loud and startling. Fly the airplane first (control, then airspeed), then work the flow and checklists in order, and divide attention between the failure, the flight path and traffic.(Risk Management Handbook (FAA-H-8083-2A))

Watch for in the airplane: Your instructor watches for attitude and rudder control on the instruments, the flow in order, a correct verify step, blue line and zero sideslip in straight flight and turns, a clear decision about where to land, and good use of ATC.

4 · Ask your student

In order: recall, then understanding, then applying it. Move up only when the answer shows it.

Recall · How do you recognize an engine failure on instruments?
A strong answer: Yaw: the heading changes and the ball moves; then I identify with the rudder and verify with the throttle.
Understand · Why does the attitude indicator matter for zero sideslip?
A strong answer: Without a horizon, it shows the small bank toward the operating engine that gives zero sideslip, with the ball partly out toward that engine.
Apply · In the clouds at 8,000 feet the left engine fails and the airplane won't hold altitude. What do you do?
A strong answer: Control, blue line, the flow, feather and secure, tell ATC I'm unable to maintain altitude, ask for a lower altitude and the nearest airport with an approach.

Scenarios to talk through

The heading swings left and the ball moves right. Which engine failed?
Sound decision: The left: the airplane yaws toward the dead engine; you'll need right rudder ("dead foot" is the left).
The minimum en route altitude is 7,000; your single-engine absolute ceiling is 5,500 and you're at 9,000. What do you do?
Sound decision: You'll drift down toward 5,500, below the MEA: tell ATC now, ask for vectors toward lower terrain or the nearest suitable airport, and declare an emergency.
In a standard-rate turn the right engine fails. What do you do first?
Sound decision: Hold the attitude, roll toward the good engine and stop the yaw with rudder, then blue line and the flow; resume the turn with zero sideslip once secured.

5 · Common student errors

Chasing heading with aileron alone.
Why it matters: Uncoordinated, losing performance.
How to correct it: Rudder for yaw, small bank toward the good engine.
Verifying on the gauges.
Why it matters: They can mislead; the throttle test doesn't.
How to correct it: Close the suspected throttle: no change confirms it.
Not telling ATC.
Why it matters: You may need lower altitudes and priority.
How to correct it: Declare and state your needs.

6 · Completion standard

Recognize, control, set engine controls, reduce drag, identify, verify, simulate feathering; best engine-inoperative airspeed and trim; checklists; troubleshoot; monitor.
Altitude ±100 feet (or minimum sink), airspeed ±10 knots, heading ±10°; decide on a safe landing and stay within the airplane's limits.
Your student answers each "Ask your student" question in their own words, up to the Apply level, without prompting.
They talk through the scenarios and reach a safe, legal decision, explaining why.
They complete the pack’s quick check and can say what they flagged.

Area trained? Close out with a practice oral focused on PA.X.C: pilotprep.pro/exam?exam=PPL&focus=PA.X.C

7 · References

Airplane Flying Handbook (FAA-H-8083-3C), Transition to Multiengine Airplanes
Instrument Flying Handbook (FAA-H-8083-15B)
Risk Management Handbook (FAA-H-8083-2A)
Private Pilot ACS (FAA-S-ACS-6C), Areas IX and X (multiengine)
Your airplane's POH/AFM, Emergency Procedures; Performance
Airman Certification Standards, task PA.X.C

PilotPrep instructor lesson plan, from the One Engine Inoperative by Reference to Instruments lesson (checked against current FAA sources 2026-11-13). A study and teaching aid, not FAA guidance; teach to your own judgment and the current ACS.