Mag Checks

[anjum_jabiru]

Hi Guys

 

I had my passenger endorsement test done today. On late finals my instructor reached out and shut off both mags at around 1800 rpm, to check if I can bring it home safely. All went well until I decided to go up again after passing my endorsement rating. During the pre-take off run up and mag checks, as soon as I switched off the left mag on the Jab with engine running at 1800 rpm, the engine quit. Believing it to be some form of oversight on my part I repeated the checks and the engine quit again as soon as I switched off my left mag. I then decided to restart the engine using both mags as usual and end the flight.

 

My question is - Is it possible that if someone switched off both mags simultaneously with the engine running at 1800 rpm in mid flight, this could result in any form of damage to the magnetos or the engine?

 

Thanks again for your input.

 

 

[Roscoe]

I think that you should be sitting down with your Instructor and going over the issues you have raised in this and other Posts Anjum.

 

 

[Fishla]

Who switches off an engine in flight?!

 

 

[Ultralights]

crazy passengers, and CFI's but if the engine only runs on 1 mag, then its not serviceable and should not fly. but shutting off both mags will do no damage to the engine of mags.

 

 

[Bruce Tuncks]

I'd be amazed if there was any damage done. The plugs may have got fouled . And shutting off the engine is ok in my opinion too. There are too many examples of pilots who have clearly panicked at the hitherto-unheard sound of silence.

 

This issue must have exercised lots of committees at RAAus and CASA over the years, and I think they have come down against doing it, except possibly under the control of an instructor.

 

You can't fly it with only one mag though. But that mag may have developed its fault anytime between the ground mags-check and when they were both turned off.

 

 

[anjum_jabiru]

I am wondering if it could be the problem with the actual switch rather than the mags. Later on the engine was running fine when it was started with only 1 mag at a time to check for faults. Is it possible for mags to work when the engine has been started in idle and then quit on a higher rpm? It somehow does not make sense to me that it should work fine sometimes and then quit on some occasions. Either the mag should work or not work. Is it possible that it might be the switch might be faulty?

 

 

[dutchroll]

I very much doubt that switching both mags off in the real aeroplane to simulate engine failure would be considered "best practice" for training or checking.

 

The student knows it was the instructor. Maybe they'll panick, maybe they won't. Who is to guarantee what the student's reaction will be if it happens for real? What if it doesn't start again when the mags are switched back on for some reason? And therefore what is the additional training/checking value versus retarding the power to idle but keeping the cylinders firing and burning the fuel which is being pumped into them either way? Zero added value for some degree of extra risk I'd say.

 

 

[Happyflyer]

anjum_jabiru, I agree with post #2. You appear have a poor understanding of aircraft systems. Can you not discuss this with your instructor or CFI?

 

As for turning off an engine, the RAAus ops manual restricts this to the CFI. It can have some use in showing if a prop will stop and at what speeds. The sound of silence is also something that possibly should be experienced before a real engine failure. I would suggest that this should be done high over an airfield and not on late finals.

 

Ops Manual Section 3.02-2

 

9. Operations with the engine stopped during flight may only be conducted by a CFI or higher approval holder in controlled conditions for emergency training.

 

 

[Ultralights]

I very much doubt that switching both mags off in the real aeroplane to simulate engine failure would be considered "best practice" for training or checking.The student knows it was the instructor. Maybe they'll panic, maybe they won't. Who is to guarantee what the student's reaction will be if it happens for real?

without an actual engine failure, how will a student know how they will react if it happens for real? better for it to happen under controlled conditions, with an instructor on board, than when the student is solo, and has never experienced the situation before!

 

flying an aircraft with the engine stopped is a completely different situation than a simulated situation with the engine at idle. the noise, the vibrations and handling of the aircraft are all different with a real stopped engine than an idling one. and the stopped engine adds that extra final layer of realism, allowing the student to know what to expect, and not panic when the engines stops for real, the silence of the engine and unusual wind noise will not be a surprise, reducing the critical time lost in the initial panic stage of an engine failure.

 

of course, all this should be done in a safe area, above an airfield, to factor in that extremely rare occurrence of the engine not restarting again.

 

Also, the glide distance with a stopped prop will be different to one that is turning. either shorter or longer.

 

 

[SSCBD]

Students in my opinion MUST experience a engine off and even more so if it a two stroke. It makes for a completely different effect in rag wings specifically can be very disturbing with noises that the engine covers up and you may think the airframe has had a failure. By the way its one hell of a shock being in any aircraft when you see the prop stop turning. If they cant land over a big runway with an engine out safely and with instructor - they don't get to fly. Simple.

 

 

[anjum_jabiru]

Roscoe & Happy Flyer - Yes, there seems to be not much point in posting these issues here or bouncing of ideas and getting the opinions of other people. Just to let you know that opinions of different people tend to differ on the same issues. I wonder if you have heard anything about group discussions and brain storming. 1 to 1 teaching may or may not be the best form of learning strategy as one is limited to the opinion of a single person rather than sharing ideas and experiences of other people who may have been involved in a similar situation.

 

I adore my CFI as he is a lovely person, experienced pilot and an excellent teacher. If my CFI shuts the engine off to check the student's reaction in a controlled environment and see if they can bring it down safely then I believe this is the best form of training.

 

 

[waraton]

Anjum I enjoy your posts. Opinions are like ......... well you know. Stick with it.

 

 

[dutchroll]

The instructor shut both magnetos off on final approach to simulate engine failure.

 

If anyone can find a reference to any well established or recognised training principle from any reputable fixed wing flight training organisation in the world which recommends this as a standard procedure and a valuable learning experience, please post it here.

 

I certainly don't mind, and expect, simulated engine failures on a check flight. But if the instructor ever actually switches my one and only engine off, the next landing will be a full stop. Just my 2 cents worth (and I've had 4 friends die in accidents as a result of "realistic training for engine out scenarios" - three of them simultaneously).

 

 

[SSCBD]

The instructor shut both magnetos off on final approach to simulate engine failure.If anyone can find a reference to any well established or recognised training principle from any reputable fixed wing flight training organisation in the world which recommends this as a standard procedure and a valuable learning experience, please post it here.

 

I certainly don't mind, and expect, simulated engine failures on a check flight. But if the instructor ever actually switches my one and only engine off, the next landing will be a full stop. Just my 2 cents worth (and I've had 4 friends die in accidents as a result of "realistic training for engine out scenarios" - three of them simultaneously).

Dutch roll - The RAA do. As posted by happy flyer above from the ops manual.

 

Ops Manual Section 3.02-2

 

 

9. Operations with the engine stopped during flight may only be conducted by a CFI or higher approval holder in controlled conditions for emergency training.

 

 

[dutchroll]

I strongly disagree with RAAus's position on it. But RAAus don't do my checks or training. so I guess it doesn't matter.

 

I think people are way overestimating the training value of it.

 

 

[jetboy]

As for the issue of mag failure, with the Jab its only lawnmower coils and they can and do fail from time to time, sometimes coming right later. Some are prone to heat failure and the current part is version #5

 

it seems you did the correct checks and returned to the hangar

 

If its a school plane then the experts can sort it

 

 

[Fishla]

What happens when the student does something stupid on short final and you can't whack the power on?

 

It's dangerous and unnecessary.

 

All my training about decision making goes against switching the engine off.

 

You make a situation less safe. That is wrong.

 

Never do something that makes you less safe. Don't take unnecessary risks.

 

Is this not what we are taught?

 

 

[Ultralights]

You make a situation less safe. That is wrong.Never do something that makes you less safe. Don't take unnecessary risks.

A LOT of glider and motor glider pilots would disagree.

 

 

[dutchroll]

.......yeah but we're not talking about a glider (or a motor glider - which is just a self launching glider).

 

How many recreational aircraft have the same glide ratio as a glider? How many have speedbrakes to rapidly dump lift in a deliberate overshoot situation without making fancy manoeuvres low to the ground?

 

If you want to talk about training scenarios you have to compare apples with apples!

 

 

[ben87r]

Got to say I agree with Dutchie here, if it occurred as reported (no reason to believe otherwise), and was late/short final and simulated by a "mag cut" I would be far from impressed. The engine off thing as a whole I've no issue with and a "mixture cut" would be considered common place in GA but would be briefed beforehand, normally on some sort of check ride and I have never seen it done anywhere that would be considered short final, If it happened,I would be equally unimpressed.

 

 

[Fishla]

A LOT of glider and motor glider pilots would disagree.

Would you disable something on your glider?

 

Today you will jump with your main chute tangled. Use the reserve!

 

 

[anjum_jabiru]

I guess that the whole point of the exercise was to demonstrate that if everything goes quiet and the propeller stops there is no need to panic and crash the plane.

 

Unlike GA the final approach in ultralights is almost always like a glide approach from a safe height above the runway.

 

It is debatable if it was the right decision had the landing gone wrong, but my guess is that a CFI would never do it unless he was confident of his student's flying skills and his own ability to salvage the situation.

 

 

[SSCBD]

I will go on the engine off side - So what happens when the - student has an engine failure for real with a non flying pax!!!! - I have seen many times the eyes of a startled deer looking at me. It brings home the whole training system to what is real and not a game.

 

They don't have to cope with other things like noise they have never heard before, or fixate on a stopped prop - so they can at least fly the aircraft - the primary job.

 

Now lets get real as well - I do admit that some, under line some CFI's and instructors I have know were not capable in all segments of training - yes its true. They are human and the whole system we fly under are under human rules and performance. Some preform better then others, same with pilots we have here just look at the landings or some comments posted on the site!!! (all smile now and take a deep breath).

 

Ready for bullets.

 

 

[Happyflyer]

If a CFI, in an aircraft that he is familiar with, in a situation such as being high over an airfield, turns off an engine to enable a student to experience an actual engine stop then I can't see a problem. There is a very high probability of it starting again, and if not you are with a very experienced instructor. Nothing is totally safe and for me, the drive to the field would be ten times more dangerous than this scenario. Turning it off on short final is a different thing. There have been many training accidents with engines being turned off but the only ones I can think of happened to multi engine aircraft.

 

 

[Fishla]

I'd implement my PAX endo training and smack you in the nose if you reach for my mag switches!