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Don’t go below it when you’re single-engine…
1) What is Vmc?
Vmc is considered to be the slowest calibrated airspeed at which, when the critical engine is made inoperative, you are still able to maintain directional control and straight fight without using more than 5 degrees of bank and 150lbs of rudder force.
Vmc is considered to be the slowest calibrated airspeed at which, when the critical engine is made inoperative, you are still able to maintain directional control and straight fight without using more than 5 degrees of bank and 150lbs of rudder force.
2) What is the difference between Vmc and minimum controllable airspeed (MCA)?
Vmc applies only to multi-engine aircraft and is describing the controllability of the plane in an inoperative engine scenario. MCA applies to all aircraft and is a speed at which any further increase in the angle of attack, increase in load factor or reduction in power will result in a stall.
Vmc applies only to multi-engine aircraft and is describing the controllability of the plane in an inoperative engine scenario. MCA applies to all aircraft and is a speed at which any further increase in the angle of attack, increase in load factor or reduction in power will result in a stall.
3) When Vmc is determined for an aircraft during testing, specific considerations and configurations are used. Which of these is not a consideration/configuration during testing?
If you go through multi-engine training, you may hear the acronym “MULTTI OPS.” It lists all the factors that are considered during certification. It stands for: maximum takeoff power, unfavorable weight and C.G., landing gear retracted, takeoff flaps, trimmed for takeoff, into the inoperative engine, out of ground effect, propeller windmilling, and standard day.
If you go through multi-engine training, you may hear the acronym “MULTTI OPS.” It lists all the factors that are considered during certification. It stands for: maximum takeoff power, unfavorable weight and C.G., landing gear retracted, takeoff flaps, trimmed for takeoff, into the inoperative engine, out of ground effect, propeller windmilling, and standard day.
4) Why does the critical engine increase Vmc?
The critical engine, when made inoperative, has the most adverse effects on controllability. This is due to factors dealing with P-factor, accelerated slipstream, spiraling slipstream, and torque on the operative engine. Since yawing and rolling forces are heightened with the critical engine inoperative, Vmc increases.
The critical engine, when made inoperative, has the most adverse effects on controllability. This is due to factors dealing with P-factor, accelerated slipstream, spiraling slipstream, and torque on the operative engine. Since yawing and rolling forces are heightened with the critical engine inoperative, Vmc increases.
5) As you climb in altitude, Vmc decreases because…
As you climb in altitude, the performance of the operative engine decreases because the density of the air decreases. So, less power produced by the operative engine means less yaw. So, Vmc decreases.
As you climb in altitude, the performance of the operative engine decreases because the density of the air decreases. So, less power produced by the operative engine means less yaw. So, Vmc decreases.
6) Which factor does not decrease Vmc?
There are many reasons why Vmc either increases or decreases, but an aft C.G. increases Vmc, it does not decrease it.
There are many reasons why Vmc either increases or decreases, but an aft C.G. increases Vmc, it does not decrease it.
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