Single engine minimum control speed (Vmc) is defined as the
minimum airspeed required to maintain controlled flight with one engine operating. Vmc airspeeds
were determined at 14° AOA for catapult launches, and 12° AOA for all other circumstances. Vmc
airspeed varies depending on AOA, lateral asymmetry, altitude, and day temperature. For an engine
failure off the catapult, 14° AOA provides the best compromise between arresting rate of descent off
the bow and controllability (increased AOA helps arrest sink but also reduces lateral-directional
controllability). In all cases, once control is established (and sink is stopped), allow the aircraft to
accelerate to on-speed to provide the best flyaway handling qualities. When an engine fails in flaps
HALF or FULL, the first perceptible aircraft motion is a yaw toward the failed engine. The rudders are
the primary flight control surface used to counter the yaw caused by the operating engine. Use rudder
to coordinate flight. Using too little rudder pedal may not counter yaw and may cause controllability
problems. In addition to yawing into the failed engine, the aircraft also tends to roll into the failed
engine. The natural pilot reaction is to oppose the roll with lateral stick, but the resulting differential
aileron deflection generates adverse yaw and increases the demand on the rudders to maintain
directional control. As AOA increases above 10° AOA, the aircraft becomes less directionally stable and
rudder control effectiveness deteriorates. In this instance, the rudders may become saturated (surfaces
against the stops). When saturated, the rudders cannot counter any additional adverse yaw, resulting
in an increase in sideslip and the potential for an adverse yaw departure. If airspeed is too slow, the
rudders cannot generate enough control power to oppose the yaw toward the failed engine.