Originally Posted by
sheppey
Reading excellent CASA Publication CAAP 5.23-1 (2) which covers multi engine training aircraft below 5700kgs.
Interestingly there is no apparent specific mention of training for engine failure during the take off roll although it is a syllabus requirement.
A recent incident at Moorabbin was discussed at a briefing. During a training flight in a light training twin the instructor cut the mixture lever at 60 knots to simulate a rejected take off due engine failure. The new student undergoing ME training immediately lost directional control caused by his delay in closing both throttles. With full power still on the live engine the aircraft veered sharply before the instructor was able to take control before the aircraft went off the side of the runway.
The student admitted he was surprised at the instructor's actions in cutting the mixture at relatively high speed shortly before anticipated lift off and was quite unprepared for the significant swing that occurred. He thought the landing gear noise of squealing tyres and near ground loop and heavy sideways strain on the landing gear would necessitate a maintenance inspection but was over-ruled by the instructor.
A simulated engine failure during a take off roll in a light twin requires instant corrective action which must be 100% right first time. Students cannot be guaranteed to get things perfect at first attempt and this type of practice emergency stop during a take off roll is a dangerous tactic. Why do some flying instructors stick their neck out as well as their student's with such manoeuvres. Answer? Sheer overconfidence coupled with bad airmanship. Where is the threat and error mitigation here? Answer NONE. CFI's please note.
The procedure for an engine failure while on the runway (although usually at speeds less than 30 knots) is to pull the mixture to cause the engine to stop. The student will feel the airplane start to swing and should immediately pull both throttles and stop the aircraft. The instructor, meanwhile, is guarding the mixtures and if the student fails to pull the throttles, s/he should then pull the other mixture off. This will prevent a loss of control and is an effective way to teach engine failure at low speed. Unless the pilot is trained in this, I will not sign off a multi engine rating. It is an important part of twin flying and should be done, safely of course, and this procedure meets that test.