VMC Flashcards
What conditions determine VMC?
Critical Engine Inop & Windmilling
Up to 5° of Bank & 0 Sideslip
Standard day temp at SLP
Trim at takeoff
Out of ground effect
Max power on operating engine
Flaps at takeoff & gear up
Aft most CG
Most unfavorable weight
Cowl flaps at takeoff
VMC Factor - Max Takeoff Power @ SLP
Increase in performance. Increases VMC.
Higher density altitude, the lower the VMC
VMC Factor - At Gross Weight
Performance decrease. VMC decrease.
In a bank, the heavier the airplane, the lower VMC is. The lighter the airplane, the higher VMC is.
VMC Factor - AFT CG
Increases performance. Increases VMC.
VMC Factor - Gear Up
Increases performance. Increases VMC
VMC Factor - Takeoff Flaps
Increases performance. Increases VMC.
Lowering the flaps increases drag and lift and helps stabilize the airplane.
VMC Factor - Windmilling Prop on Critical Engine
Decreases performance. Increases VMC. A windmilling prior creates unbalanced drag and and creates less directional control.
VMC Factor - Cowl Flaps Takeoff
Decrease performance. Decrease VMC.
VMC Factor - Out of Ground Effect
Increases VMC. Decreases performance. As induced drag is created, the airplane’s VCM is increased and the performance is decreased.
VMC Factor - Up to 5° Bank and Zero Sideslip
Decreases VMC. Increases performance.
What is the definition of VMC?
VMC is the calibrated airspeed, at which, when the critical engine is suddenly made an operative. It is possible to:
1. Maintain control of the airplane with the engine, still in operative.
2. Maintain straight flight at the same speed with an angle of bank, not more than 5°.
As airspeed decreases the rudder becomes less effective, eventually an airspeed will be reached where full or deflection will be required to maintain directional control. This airspeed is VMC. Any further reduction in airspeed will result in loss of directional control.
VMC Factor - Increase in Temp.
Lowers VMC & Perofrmance
VMC Factors - Decrease in Pressure
Lowers VMC & Performance
VMC Factors - Increase in Altitude
Lowers VMC & Performance
