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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 6th Jun 2017, 10:02
  #21 (permalink)  
 
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Originally Posted by 27/09 View Post
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.
Correct, it is a recommendation of Lycoming to use the mixture.

It's also very easy for a student to identifie the correct engine when there is only one throttle to play with.

We have all heard the stories of pleople shutting down the wrong engine.

I have had many students identifie the wrong engine. Glad they did it with me, not when it's the real deal.

Last edited by CAVOK92; 6th Jun 2017 at 10:21.
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Old 6th Jun 2017, 10:25
  #22 (permalink)  
 
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A good article on engine failures.
Sample Chapter - Flying Wisdom, Proficient Pilot 3 by Barry Schiff
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Old 6th Jun 2017, 14:50
  #23 (permalink)  
 
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I usually make it a practice to hide the mixture controls from the student with a large piece of cardboard or a manila folder. In this way, he cannot determine which engine has failed by glancing at the mixture-control levers. This technique gives the student access to the throttles and propeller-pitch controls, and he is forced to go through the procedures just as if the engine had genuinely failed.
Quote is from Schiff link. Evidence from surviving pilot revealed the instructor used this technique in the Camden Duchess fatal accident a few years back. Except he couldn't get the dead engine back to life fast enough before clipping trees and stalling into the ground.
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Old 6th Jun 2017, 15:21
  #24 (permalink)  
 
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Pray tell us your theories around this assertion.
Creamie,
I always love this one, it immediately reveals a certain gap in the knowledge of what happens inside an engine.
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Old 6th Jun 2017, 19:23
  #25 (permalink)  
 
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Originally Posted by Centaurus View Post
Quote is from Schiff link. Evidence from surviving pilot revealed the instructor used this technique in the Camden Duchess fatal accident a few years back. Except he couldn't get the dead engine back to life fast enough before clipping trees and stalling into the ground.
I'd suggest the problem wasn't so much the technique but more where or at what height the simulated failure was initiated or how far the instructor let things develop before intervening.
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Old 7th Jun 2017, 16:29
  #26 (permalink)  
 
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I was taught, dead leg, dead engine and to TOUCH the dead leg to confirm you were securing the correct powerplant. I never looked at the throttles or mixtures to identify which side was failed as it was a waste of time since it wouldn't help during an actual failure and IMO took away from the training.


Is the touch the dead leg not taught anymore?
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Old 7th Jun 2017, 22:20
  #27 (permalink)  
 
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Old Phil Zupp made me slap the dead leg hard - not 'touch' it
- certainly made you aware
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Old 7th Jun 2017, 22:46
  #28 (permalink)  
 
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I don't know the people involved or the detail of the accident. But there is a pretty long history of accidents with CASA pilots on board. I think the earlier poster who raised questions about the cockpit dynamics with someone on board who has the unchallengeable power of a CASA person deserves reflection more than trading opinions on asymmetric training techniques.
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Old 7th Jun 2017, 23:33
  #29 (permalink)  
 
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questions about the cockpit dynamics with someone on board who has the unchallengeable power of a CASA person deserves reflection
There is a story in the community about a CASA officer wanting to see a stall in a Metro, as it was a box he had to tick on checking the pilot. Wanted the pilot to disable the stall protection in order to achieve stall. Unable to find report on ATSB, but told it was at Lake George.
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Old 8th Jun 2017, 00:44
  #30 (permalink)  
 
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Megan,
Not a story, but a fact, said FOI wanted the SATS c/b puller. The head of training refused, which had calamitous consequences for his career. It was Avtex Aviation at YSBK. There were some "interesting" discussions about "the law" versus AFM limitation.
"We" finally had the Type Certificate holder in US write a letter saying that such a manoeuver was absolutely prohibited, except in test conditions, with a spin recovery parachute fitted.
As fate would have it, due to an inadvertently not reset SATS c/b, a Norwegian Metro was lost on a training flight in a deep stall ---- a hard way to prove the point.
I my opinion, to this day, it is unlikely that the FOI involved understands deep stalls in a T-tail aircraft.
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Old 8th Jun 2017, 10:24
  #31 (permalink)  
 
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Originally Posted by LeadSled View Post
Avtex Aviation at YSBK.
Avtex Air Services Pty Ltd trading as Airtex Aviation.
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Old 8th Jun 2017, 14:26
  #32 (permalink)  
 
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Correct, it is a recommendation of Lycoming to use the mixture.

It's also very easy for a student to identifie the correct engine when there is only one throttle to play with
That is a selective quote. In fact Lycoming Flyer Key Reprints magazine published an NTSB Warning of the dangers of cutting mixtures at low altitude to simulate engine failure.
Read on:

Warning on Simulated Engine-Out Manoeuvres.

“In mid 1976, the NTSB issued an urgent warning to all pilots simulating an engine-out condition on multi engine airplanes, to eliminate actual engine shutdown and substitute instead reduction of power at low altitudes such as traffic pattern. The recommendation resulted from the NTSB investigation of the fatal crash of a light twin in which a flight instructor and an applicant for a multi-engine rating were killed. The Board’s investigation revealed that some flight instructors do use the fuel selector or the mixture control to shut down an engine to test a multi-engine applicant.

The NTSB observed that the use of such procedures at traffic pattern altitude may not permit instructors time enough to overcome possible errors on the part of the applicant. The recommendation by the NTSB means that all simulated engine-out operation at the lower altitudes will have to be accompanied by retarding the throttle and unless this is executed slowly and carefully – engine failure can result. Many flight instructors down through the years used the technique of abruptly cutting an engine with a multi-engine candidate to test his emotional reaction and judgement with this extreme technique…..however, any practice on simulated engine-out condition at low altitudes should be best accomplished by a slow retardation of the throttle in accordance with the NTSB recommendation. This careful technique will protect the engine, and at the same time provide for instant power if it is needed”.
............................................................ ..............................

The NTSB viewpoint was shared by the British CAA who published a similar argument for throttle closure in their AIC 52/1999 (Pink 193) date 6th May 1999 and titled “Guidance to Training Captains – Simulation of Engine Failure in Aeroplanes. Quote in part: “Generally the throttle may be initially moved smoothly to the closed position; the mixture control or Idle Cut-Off should not be used to simulate engine failure. Reference to the engine manufacturers should clarify the technique in particular cases. When the trainee has identified the “failed“ engine and completed his “touch only” feathering drill, the throttle should be advanced to the zero thrust position”.

The Piper Seminole Information Manual at Section 10, entitled Training Tips states:
“Experience has shown that the training advantage gained by pulling the mixture control or turning off fuel to simulate engine failure at low altitude, is not worth the risk assumed, therefore it is recommended that instead of using either of these procedures to simulate loss of power at low altitude, the throttle be retarded slowly to idle position”.
............................................................ ....................................
Flying school operators with PA44 Seminoles who still teach mixture cuts after take off to simulate engine failure would be legally wise to heed the warnings against the practice published in their own POH

Last edited by Centaurus; 8th Jun 2017 at 14:39.
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Old 9th Jun 2017, 03:48
  #33 (permalink)  
 
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Centaurus,
Thanks for that, and NOT an eyeopener to those of us who have been around quite a while. I hope some (all??) will read, and learn.

Sadly, I think you are of the belief that facts have any "impact" on prejudices. Never let the facts spoil a good story.

Just look at many of the posts on this thread, the naive but firmly held belief that what "they" are doing is not just OK, but necessary for asymmetric training, and they are so competent and mistake-proof, that they can "safely" defy the odds.

As ever, a significant proportion of Australia's aviation community does not even really accept the concepts of genuine formal risk assessment, and mitigation. That is, "they" do not accept rational risk management, "they" are so "competent", in their own eyes, that risk mitigation is entirely irrelevant.

Another example is the generally irrational negative attitude to ICAO airspace classification, firmly grounded on risk assessment and mitigation, in favour of "that the way we do it in Australia", from too large a proportion of the Australian aviation community.

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Old 9th Jun 2017, 05:16
  #34 (permalink)  
 
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I have been sitting in the wings quietly reading this thread. I have nothing to offer in the way of expertise in this area other than having trained on many of the common avgas powered light twins (PA23, PA30, PA31, BE76, Baron, C310, C402 - I have no turbine time) and undertaken many IR renewals in same.

I have only flown these activities with very experienced and highly regarded instructors.

I cannot recall an engine failure on take off having ever been simulated other than by using the mixture control!

Dr
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Old 9th Jun 2017, 06:33
  #35 (permalink)  
 
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I'm with you Dr. I must say I'm a bit perplexed by all this. I'm no expert on the matter and I'm certainly not trying to contradict others on here who clearly have vastly more experience and expertise than me, but when I did my initial twin training and further training on other types, like the good Dr, simulated engine failures were always done using the mixture control. As far as I'm aware, all the schools at MB were using this method, and presumably still are. (And at low level too ie in the circuit).


My question is, if this method is so inherently dangerous, and given the amount of twin training that happens at MB and elsewhere, why haven't there been more accidents of this type during training and proficiency checks..? Have we all just been incredibly lucky..?!
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Old 9th Jun 2017, 06:47
  #36 (permalink)  
 
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Originally Posted by IFEZ View Post
My question is, if this method is so inherently dangerous, and given the amount of twin training that happens at MB and elsewhere, why haven't there been more accidents of this type during training and proficiency checks..? Have we all just been incredibly lucky..?!
Put the shoe on the other foot.

How many accidents have occurred as a result of an actual engine failure on takeoff in a piston twin? Less than those caused by training for an engine failure on takeoff, I'll bet!
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Old 9th Jun 2017, 07:01
  #37 (permalink)  
 
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Hmmm, I see your point..!
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Old 9th Jun 2017, 08:21
  #38 (permalink)  
 
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For those that still have their doubts about their own mixture cuts during their training, it is worthwhile reading this CASA CAAP. Part of it is reproduced below. Notwithstanding all the official evidence of the folly of playing around with mixture cuts as part of take off asymmetric "training," there is anecdotal evidence this practice is still happily used at some Australian flying schools. The advice contained in the CAAP is thus disregarded under the old chestnut of "but I've always done it and had no problems, so why should I change?"

why haven't there been more accidents of this type during training and proficiency checks..?
The mishandling and close shaves invariably associated with mixture cuts at low altitude in all probability never get reported by instructors..
............................................................ ..........................................

September 2015
CAAP 5.23-1(2)
Multi-engine aeroplane operations and training
This CAAP will be of interest to:
 multi-engine aeroplane pilots
 flight instructors
 approved testing officers (ATO)
 flying training providers.
Why this publication was written
Following a number of multi-engine aeroplane accidents caused by aircraft systems mismanagement and loss of control by pilots, flight instructors and persons approved to conduct multi-engine training, this CAAP was written to address threats and errors associated with multi-engine operations and provide advice on multi-engine training. This CAAP also includes competency standards for multi-engine operations, suggested multi-engine and flight instructor training syllabi and a questionnaire to assist pilots to learn and assess their aircraft systems knowledge.
Status of this CAAP
This is the third CAAP to be written on this subject. This CAAP will be superseded with a Part 61 Advisory Circular (AC) in the future.
For further information
Telephone Flight Standards Branch on 131 757.
Civil Aviation Advisory
Publication
September 2015...................
............................................................ ......................

The relevant paragraph dealing with practice engine failures states:
6.8 About engine failures
6.8.1 Flight instructors often simulate an engine failure by rapidly closing the throttle or moving the mixture control to idle cut-off. The latter method should never be used at low altitude


According to the earlier quoted NTSB report published in Key Reprints from Lycoming Flyer, throttle closure should be done slowly to prevent engine failure or damage.

Last edited by Centaurus; 9th Jun 2017 at 08:31.
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Old 9th Jun 2017, 08:48
  #39 (permalink)  
 
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Originally Posted by IFEZ View Post
I'm with you Dr. I must say I'm a bit perplexed by all this. I'm no expert on the matter and I'm certainly not trying to contradict others on here who clearly have vastly more experience and expertise than me, but when I did my initial twin training and further training on other types, like the good Dr, simulated engine failures were always done using the mixture control. As far as I'm aware, all the schools at MB were using this method, and presumably still are. (And at low level too ie in the circuit).


My question is, if this method is so inherently dangerous, and given the amount of twin training that happens at MB and elsewhere, why haven't there been more accidents of this type during training and proficiency checks..? Have we all just been incredibly lucky..?!
No I don't think so.

I'm at a loss to understand exactly why the throttle is being promoted as a safer way to simulated an engine failure. The only explanation offered is the engine responds more reliably. I've never had an issue with using the mixture.

It's my hypothesis that a significant proportion of training accidents are caused by either the instructor trying to be too "realistic" and/or simulating at inappropriate altitudes or in inappropriate conditions. If the difference in safety is a matter of whether or not the mixture or throttle is used then I'd venture to suggest the timing of the simulation was inappropriate.

Last edited by 27/09; 9th Jun 2017 at 09:00.
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Old 9th Jun 2017, 09:44
  #40 (permalink)  
 
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I'm at a loss to understand exactly why the throttle is being promoted as a safer way to simulated an engine failure
Surely that should be obvious? You have instant power available should the circumstances require it. With a mixture cut you have failed the engine and instant power is not available if the student stuffs up. To re-start the engine after a mixture cut the instructor first has to close the throttle of that engine. Secondly he has to advance the mixture to open. Thirdly he has to restore power by re-opening the throttle either to zero thrust to simulate feathering the prop or to restore to climb power if the exercise is completed.
Another factor is the type of engine. If fuel injected and the mixture is cut there is a possibility that depending for how long the mixture has been cut, fuel in the injector lines may not be instantly available and you are left stranded with not only a windmilling prop (big drag) but no power until the fuel is running again. All the time the student could be getting out of his depth while you are sorting out the fuel problem and leaving him to it.

At Tyabb this is exactly what happened some years ago and the aircraft crashed and caught fire. The instructor cut the mixture lever while joining the circuit and the student was required to fly the circuit with a windmilling prop - not a zero thrust prop. To add insult to injury the instructor told the student it would be a touch and go as he would start the engine just before touch down. The student opened up both throttles after touch down to do the touch and go. Unfortunately the "failed" engine failed to deliver power due to fuel in the injector lines having been diminished. The student lost directional control, the instructor now with his hands full took over control, but departed the airstrip and hit a log of wood. The aircraft caught fire causing minor burns to the two pilots. A simple throttle closure to simulate engine failure would have been a safer option but the instructor wanted to give the student the practice of flying a circuit with a windmilling prop on a real dead engine. Not an example of good airmanship in anyone's language
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