Definition
The minimum airspeed at which a multi-engine aircraft can be controlled in flight after the sudden failure of one engine, with the critical engine inoperative and its propeller windmilling, takeoff power on the operating engine, and the aircraft in its most unfavorable takeoff configuration. Below this speed, directional control cannot be maintained using full rudder and limited bank.
Plain English
The slowest speed at which a twin-engine plane can still be steered straight if one engine quits. Fly slower than this with an engine out, and the working engine will swing the nose around faster than the pilot can stop it.
Context Anchor
Seen in aircraft maintenance and electrical troubleshooting, especially when checking batteries, wires, switches, lights, or radios.
Derivation
From the V-speed system used worldwide to label key airspeeds. The 'mc' stands for 'minimum control,' and the small 'o' indicates 'one engine inoperative.' Knowing the subscript is short for 'one out' makes the symbol easier to remember.
Why Pilots Care
Accurate electrical checks prevent in-flight failures of critical systems such as ignition, navigation, and fuel pumps.
Analogy
A VOM is like a basic health check tool for an electrical circuit: it helps the technician see whether electricity is present, blocked, or flowing in the expected amount.
Intuition Check
Do not confuse a VOM with a cockpit flight instrument. A VOM is a maintenance test meter used on electrical systems.
Example Sentence 1
The instructor demonstrated engine-out handling at a safe altitude, showing how directional control degraded as the airspeed approached Vom.
Example Sentence 2
With the VOM set to ohms, the mechanic checked the continuity of the landing-light circuit.