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Simulated engine failure after take off in light piston engine twins

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Simulated engine failure after take off in light piston engine twins

Old 4th Jun 2017, 14:28
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Simulated engine failure after take off in light piston engine twins

Those who have followed the discussion on the Conquest 441 accident at Renmark would note that much of the comment revolves around the possibility of a practice engine failure after take off gone wrong.

The following link sent by a reader on the thread is a relevant ATSB report on a practice engine failure in a Beech 1900.
https://www.atsb.gov.au/media/24342/...000492_001.pdf
I commend it to all multi-engine aircraft flying school instructors even though it deals with practice turbo-prop engine failures and not those on light piston twins typically used by flying schools.

It is probable that most flying schools engaged in initial twin engine endorsement training use a standard mantra of mixture up - pitch up- throttles up - gear up - flap up - identify failed engine by dead side dead leg - confirm with throttle - and finally feather.

All the time the simulated failed engine throttle is closed hard against the mechanical stop - or if the mixture lever was used to cut the engine - the throttles are both still forward at take off position. Either way, the propeller of the "failed" engine is windmilling and producing significant drag until the pilot gets through the engine failure mantra and finally either feathers the prop (assuming a real engine failure) or the instructor sets the throttle and pitch lever to a guesstimate of zero thrust.

With a windmilling propeller, airspeed will decrease unless the pilot deliberately lowers the nose and loses height in order to maintain safe single engine flying speed. He will probably be criticised for deliberately losing height to maintain airspeed especially if he is under the hood in simulated IMC. In other words he can't win

It could be upwards of 15 seconds going through the engine failure mantra until he gets around to "feather." All the while the "failed" engine is producing lots of drag. See the ATSB report. It may not be as severe as in a turbo-prop simulated failure but nevertheless it is bad enough to cause rapid speed loss. All this below 500 feet means the risk of loss of directional control is substantially increased as long as the prop windmills.

To mitigate (don't you just love that buzz-word) that risk or manage that "threat" as in Threat and Error Management (love that buzz-word too), CASA note perhaps it would be safer, if instead of closing the throttle against the stops to simulate engine failure, the instructor would reduce the throttle to the approximate zero thrust position on the quadrant and announce "simulated engine failure."

There is no need to increase the risk of mishandling by allowing the huge drag from a windmilling propeller to ruin your whole day while you get around to muttering the mantra and eventually get around to setting zero thrust.
There must be a limit to faking realism in asymmetric training. The current acceptance of reducing airspeed causing increased yaw and drag associated with failure to set the throttle to zero thrust to simulate engine failure, needs to be reviewed.

Last edited by Judd; 4th Jun 2017 at 14:41.
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Old 4th Jun 2017, 14:59
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I think the ultimate problem will be - way too much experience in the pilots on board.

The seen boss will be the CASA person by crew - They do bash that big stick often.


Then the 2 crew, both with big experience.


Who will say what when wen it is not as planned?


To many chiefs on this brief is possible!
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Old 4th Jun 2017, 21:49
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It would be a lot safer for the instructor to call out "engine failure right engine" with no engine input.

Multi engine instruction has its risks. All flight training has risk involved. It is up to the instructor to step in before the aircraft and crew are positioned in a un safe situation.

There is a reason you need to do a multi engine training approval before you go simulating failures.

There is a reason you need to see exactly how the aircraft with perform when an engine fails.

There is a reason you need to feather the propeller when the engine failes. There is a big handeling and performance difference which the candidate needs to see and practice.

There has been a couple of threads recently that have made me start to worry about the current quality of multi engine instructors. It makes me sick thinking about the poor kid that is going to kill himself and his family when an engine stops all because he never received adequate assymetric training.


ME turbines are a diferent beast and need to be treated with even more respect. There is a reason they make you do the training in a simulator if one is available.
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Old 5th Jun 2017, 00:52
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It could be upwards of 15 seconds going through the engine failure mantra until he gets around to "feather."
Sorry but if you're taking 15 seconds to get through the mechanical drill, I would have said something like "you've got the idea but you've got to be up to standard ... I think you need another session of assy circuits." I would not put someone up for a rating test at that standard.

The whole point of this training is to know what really happens (close throttle is a clean best-case engine failure, plenty are more confusing). And to handle it in sensible fashion. Both of these need as realistic practice as can be done safely. When it really happens, you will go into pause mode - minimum pause is good
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Old 5th Jun 2017, 01:22
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An unfortunate statistic.
6.3.2 ATSB statistics indicate that 16% of multi-engine aeroplane accidents occur during training or assessment. Unfortunately, a number of these accidents were caused by unsatisfactory behaviour by instructors or ATOs.
https://www.casa.gov.au/file/104981/...token=HK_Z2wzP

Practising bleeding leads to the real thing on occasions. Vale Les Morris.
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Old 5th Jun 2017, 01:31
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well I'll say it, drpixie, how does one feather a piston engine prop in much less than 15 seconds
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Old 5th Jun 2017, 06:49
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While engines can and do happen at any point of a flight profile, there is absolutely no need to simulate engine failures at critical phases of flight where, if the exercise is not properly handled, will likely result in the loss of the aircraft and occupants.

Remember we are either training to do the engine failure properly or checking to see the candidate can do it properly. This can be achieved at heights that allow room for recovery if there is a stuff up.
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Old 5th Jun 2017, 09:54
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The limited twin training I've done was in a PA30.
One of the exercises was to practice an approach from about 3500', dirty. Airfield elevation was assumed to be 3000'. At 3300' the instructor commanded an overshoot, and failed the right engine. I responded promptly with the required rudder, and lowered the nose to maintain the blueline. I remember being surprised at how aggressively and how much I had to lower the nose, and we only just maintained the required speed. It took me maybe 10 seconds to identify and feather the powerplant, and to raise flaps to takeoff setting, then we started a leisurely climb. From 2800'.

The instructor told me that sort of height loss at the weight we were was fairly representative, and you'd be doing extremely well to only lose 300'.

Lose an engine below about 500-1000 on departure on the average, fairly underpowered training twin, you're basically going to look for the best place to put it down, more or less straight ahead.

There is no need to do such training so low. The demo I experienced was quite graphic.
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Old 5th Jun 2017, 09:59
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Originally Posted by Xeptu View Post
well I'll say it, drpixie, how does one feather a piston engine prop in much less than 15 seconds
Note that you're expecting the "failure" (and you'll see your instructor's hand reaching for the mixture) so there should be no "surprise" time (unlike real life):
- you keep the aircraft straight with normal controls (primarily rudder) and notice the failure - 1 second
- mix, pitch, power UP - one hand, one second
- identify "dead leg" - one second
- confirm by closing throttle - one second
- identify and pull the pitch to feather - one second
- then check gear & flaps & blue line
with minor variations in order depending on the aircraft (check your POH & SOPs).

That makes it about five seconds - I wouldn't care if it takes a little longer as long as the aircraft is flown for good performance (blue line), no significant loss of altitude, and you don't take the wrong engine!

For average small & medium twins, you should be able to do that quite mechanically and without loosing any altitude. If you are loosing altitude, or getting below blue line, then I don't want my family in the aircraft with you - because real engine failures do happen.

And Tarq57, Lose an engine below about 500-1000... I absolutely agree - got to be familiar with your aircraft and should have a "committed" height nominated - below that, you're going to land somewhere.

Too all up-and-coming multi-engine pilots - you're moving into a more serious regime - bigger, faster, more powerful aircraft with more pax. You've got to learn from other people mistakes because sometimes you'll only get one chance. So be very familiar with some kind of take-off briefing, Vmc, sensible initial climb attitude & speed, after T/O decision point, before landing committed point, actions to perform on engine failure before & after decision point. There are a couple of quite good multi-engine books, available at more pilot shops. If your instructor doesn't know & stress these things, find another one.

Last edited by drpixie; 5th Jun 2017 at 10:13.
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Old 5th Jun 2017, 11:51
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Committed height is bollocks. (more on that)

15 seconds to go through the mantra...about right, including stabilising. Should be doable quicker at test stage.

The reason i call bollocks on committed height comes from my limited knowledge of what is taught in BPPP.
Their training on barons, is that if the flaps and wheels are not up, then it it close both throttles and land ahead. Treat the aeroplane as a single.

As for an instructor doing the simulation by a mixture cut...that will be the end of the flight for me. Its a training flight! Throttle cut, that way if i get it wrong, then either of us can bring the throttle up again. Sure still not instantaneous, but a dammed sight quicker if you are 3/4 through the drill and need power.

As for zero thrust, we all rely on our instructors to know those numbers. Mine made me learn them and correct him where required. he probably didn't need me to tell him, but me knowing them also gave a safety scope in that I knew what was needed and if outside of it i could call a halt to the exercise.
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Old 5th Jun 2017, 14:49
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ME training technique engine failure during take off roll

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.
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Old 5th Jun 2017, 15:10
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Old 5th Jun 2017, 20:33
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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.
That is why the instructor who is carrying out the exercise, who knows what he, or she, is going to do, should be ready to immediately rectify the situation if the student does not get it right.
 
Old 5th Jun 2017, 21:57
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Sounds like the instructor wasn't doing his job properly to me. No practiced engine failure on takeoff roll should result In a runway excursion. It is the instructors responsibility to rectifie the situation before it results In loss of directional control.

"Student was surprised [by how the aircraft handled]". That why there is a reason it should be precticed with the proper safety measures in place.
- ghost the rudder to prevent the opposite input.
- have your hand on the other mixture should the student not have a satasfactory response.
- If your going to stuprise the student, don't do it at 60kts.

Assymetric operation can be safely practiced however it requires the person in the right hand seat to be diligent and considerate of the possible threats and errors that could be experienced.
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Old 5th Jun 2017, 23:23
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No PM received Centaurus.
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Old 5th Jun 2017, 23:54
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Originally Posted by jas24zzk View Post
Committed height is bollocks ... is that if the flaps and wheels are not up, then it it close both throttles and land ahead.
So they have a committed config instead of a committed height but same idea, after some defined point in the approach, you will not be able to go around on one engine.
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Old 6th Jun 2017, 02:32
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Old 6th Jun 2017, 08:30
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Originally Posted by jas24zzk View Post
Committed height is bollocks. (more on that)

15 seconds to go through the mantra...about right, including stabilising. Should be doable quicker at test stage.

The reason i call bollocks on committed height comes from my limited knowledge of what is taught in BPPP.
Their training on barons, is that if the flaps and wheels are not up, then it it close both throttles and land ahead. Treat the aeroplane as a single.

As for an instructor doing the simulation by a mixture cut...that will be the end of the flight for me. Its a training flight! Throttle cut, that way if i get it wrong, then either of us can bring the throttle up again. Sure still not instantaneous, but a dammed sight quicker if you are 3/4 through the drill and need power.
Do you mean committal height? If so then I have to disagree. Asymmetric committal height is something all light twin drivers should think about for every landing. Below that height you're committed to land as a single engine go around will most likely result in a touch down anyway.

I've never heard of a commit height for departure. Blue line achieved and gear up are the milestones for departure.

Simulating engine failures by closing the throttle isn't the best method in my opinion.

A mixture cut is kinder in the engine pistons and rings and gives indications that more closely resemble a real engine failure in a normally aspirated aircraft. In other words the manifold pressure and RPM indications mimic a real engine failure.

Closing the throttle gives a false manifold pressure indication and the throttle lever is in the wrong place for the drills that need to take place.

I've never had an issue bringing the power up from mixture cut.
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Old 6th Jun 2017, 09:23
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Sorry Drpixie, missed the clarification in your response to tarq57. He specifically mentions departure, whilst you mention approach.

Cheers
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Old 6th Jun 2017, 09:31
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A mixture cut <snip> gives indications that more closely resemble a real engine failure in a normally aspirated aircraft. In other words the manifold pressure and RPM indications mimic a real engine failure.

Closing the throttle gives a false manifold pressure indication and the throttle lever is in the wrong place for the drills that need to take place.

I've never had an issue bringing the power up from mixture cut.
Correct and unsurprising, although in some cases the resumption of power may depend on the specific fuel system fitted to the particular engine and aircraft.

But I have the popcorn ready for this one:
A mixture cut is kinder in the engine pistons and rings ...
Pray tell us your theories around this assertion.
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