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AviationVMC demonstration
At a safe altitude, with the critical engine at idle and the other at full power, you slow the twin about one knot per second until it starts to lose directional control, a stall warning or buffet, and recover at once. It is Task B of Area X, Multiengine Operations, in the FAA Private Pilot Airman Certification Standards, for the airplane classes listed below.
Free to startScenarios
- Airplane multiengine land (AMEL).
- Airplane multiengine sea (AMES).
The steps
- Configure the airplane as the manufacturer recommends or, without that, at the safe single-engine speed (VSSE or VYSE) with the gear up, flaps, cowl flaps and trim set for takeoff, propellers at high rpm, the critical engine at idle with the propeller windmilling and the other engine at takeoff or maximum power.
- Set a single-engine climb attitude with the airspeed about 10 knots above VSSE.
- Set a bank of no more than 5 degrees toward the operating engine, as needed for best performance and control.
- Raise the nose slowly to lose airspeed at about 1 knot per second, adding rudder as needed to keep directional control.
- Recognize and recover at the first sign of loss of directional control, a stall warning or buffet.
- Recover promptly by reducing power on the operating engine enough and lowering the angle of attack as needed to regain airspeed and directional control, without adding power on the simulated failed engine.
- Recover within 20 degrees of the entry heading.
- Advance power smoothly on the operating engine and accelerate to VSSE or VYSE, +10/-5 knots, during the recovery.
Safety rules that stop the station
- Never enter by pitching up high with both engines running and then cutting power on the critical engine: it can lose control of the airplane.
- Feathering or shutting down an engine is done only where a safe landing on an established airport is possible, with the single-engine work ending no lower than 3,000 feet above the ground or the manufacturer's altitude, whichever is higher.
- Any action, or lack of action, that makes the examiner step in to keep the flight safe is unsatisfactory.
- Not clearing the area with a proper visual scan before and during the maneuver is unsatisfactory.
- Consistently exceeding the tolerances of the task, or not correcting promptly when you exceed them, is unsatisfactory.
To pass
- Recovery at the first sign of lost control, a stall warning or buffet, within 20 degrees of the entry heading, and VSSE or VYSE +10/-5 knots.
- Know what changes VMC and how it differs from the stall speed, VMC (red line), VYSE (blue line) and VSSE, why directional control is lost below VMC, how to enter and recover safely, and the risks of configuring the airplane, maneuvering on one engine and distractions.
- Missing the standard on this task fails the task and its area of operation.
Official source
Federal · FAA Private Pilot ACS
Private Pilot for Airplane Category Airman Certification Standards (FAA-S-ACS-6C)
The FAA publishes the Private Pilot Airman Certification Standards free: every task of the checkride with its knowledge, risks and tolerances.
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