The condition applying to multiengine aircraft following the loss of power from an engine mounted either side of the centre line
What are the two yaw moments
Weathercock Yaw Moment
Thrust Yawing Moment
What factors effect the size of the yawing moments
Engine thrust
Moment arm
Aircraft directional stability
Rate of thrust decay
Drag of failed prop
Assymetric blade effect (Downgoing blade and RAF)
What factors effect the size of the rolling moment?
Magnitude if yawing moment
Torque of the live engine (engine torque acts opposite to engine rotation)
Loss of slipstream
What are the two practicle methods of achieving constant heading assymetric flight
All rudder - used in high speed flight
Rudder and bank - used in takeoff
What are cockpit indications of all rudder method
Wings level
Ball in centre
Cocked off
What are cockpit indications of Rudder and bank method
5 deg AOB
Ball displaced toward live engine
Tracking straight ahead (no drift)
What is the critical engine
The one that if fails results in higher assymetric moment from the live engine
Critical engine is the failed one
Live engine has a higher assymetric moment due to down going blade effect (Phenomenon present when ever there is any aircraft angle of attack as down going blade will have higher AOA to the RAF)
What is Vmca
Minimum control speed - air
The minimum IAS at which during takeoff, in the event of a sudden complete engine failure, it is possible to maintain directional control and steady flight using full rudder deflection and 5deg AOB
What is Vmcg
Minimum control speed - ground
The minimum IAS under takeoff power at which directional control of the aircraft can be maintained using rudder alone following a failure of the critical engine during take off ground run