Ground Minimum Control Speed
Vmcg is the minimum airspeed during the takeoff ground run at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the aircraft using rudder alone and takeoff safely while maintaining takeoff power on the remaining engines.
Vmcg conditions
- No.1 engine failed and the propeller auto-feathered
- Maximum takeoff power on remaining engines
- Automatic Thrust Control System (ATCS)
- Maximum rudder deflection limited by 150 pounds of rudder force or maximum rudder deflection
- Flaps 50 percent
- Minimum takeoff weight
- No nosewheel steering required
- Maximum lateral deviation from initial runway heading track of 30 feet
Minimum Power Restoration Speed
Vmpr is the speed at which rudder control is strong enough to overcome the yawing moment of the operating outboard engine at full power.
It is the speed ATCS will have restored full power back to the operating engine.
Vmca2 Conditions
- No. 1 and No. 2 engines are inoperative; the No. 1 propeller is wind milling or feathered and the No. 2 propeller auto-feathered
- Maximum takeoff power is set on the two remaining engines
- One hundred and fifty pounds of rudder pedal force, or the maximum rudder deflection
- Flaps set at 50 percent
- Minimum flying weight
- Bank angle of 5 degrees away from the failed engines
- Rudder trim is as required for a three-degree glide path with three operating engines
- Landing gear is down
Critical Field Length
The distance required to accelerate on all four engines to the critical engine failure speed, lose an engine, then continue the takeoff, or stop within the same distance.
Refusal Speed
V1 is the speed at which an engine failure could occur and the aircraft could abort the takeoff a stop within the runway distance remaining.
Assumes two symmetrical engines in reverse, one engine ground idle, one engine feathered, max anti skid braking, and the aircraft is in the three point attitude.
Critical Engine Failure Speed
Vcef is the highest speed at which an engine failure could occur and the aircraft could either successfully takeoff or safely stop on the runway.
Brake Energy Limit Speed
Vmbe is the speed at which the brakes, in stopping the aircraft, will reach their maximum energy absorption limit.
Vmca1 Defining Conditions
- ATCS operational
- No. 1 engine failed, prop Auto-feathered
- Max T/O power commanded on all engines
- Max rudder deflection limited by 150 lbs rudder force or maximum rudder deflection
- Zero rudder trim
- Minimum flying weight
- Bank angle _< 5 degrees away from the failed engine
