Understanding How The Magneto's Work - Maintenance Mondays - MzeroA Flight Training
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- เผยแพร่เมื่อ 29 ส.ค. 2024
- m0a.com Wrapping up our series with Champion Aerospace by sharing more about our Magnetos. Will the engine keep running if the battery dies? Should we do a magneto ground check? We'll answer these questions in todays video.
I used to work for Unison industries where we used manufacture and assemble the magnetos and coild before Champion Aerospace bought them out. I use to run the coil winding machine.
WOW! Zach really explains the magneto in a simple way that is easy to understand. Thank you!!
*this whole video was really well explained, and I learned so much in under 10 minutes. thank you for sharing, and they both did so well at explaining!*
Glad it was helpful! Thanks for watching!
Please keep doing these videos! Extremely helpful!
Excellent series, Jason! This is a wing-rockin' primer in firing up further detailed study and discussion.
These guys are awesome
Thanks for the insight
After the Fuel, I guess Magnetos are the 2nd soul of the piston engine airplane
Glad you enjoyed it! Thanks for watching!
Just found this vid…amazing and very informative. I now have a full appreciation and understanding of the magnetos and their function. Wow didn’t know it can generate 20k volts. That’s a serious kicker. Thank for doing this video. Cheers
Glad you found the content useful! Thanks for watching, Reza!
Magnetos have two coils. A primary and a secondary - magnet charges the primary, and the primary dumps into the secondary via step-up turns ratio. Grounding the primary (ie shorting the primary coil start & finish together) kills the ignition via the secondary not being driven by the dead primary.
Thanks for watching, Jon!
Outstanding video and very easy to understand. Thank you!
Grammar nit: "Magnetos". Apostrophe is for possessive: "The left magneto's drop is excessive; the right is OK."
What a great team! Thanks for the info.
Our pleasure!
Pretty sure that the magneto is DEAD when the key switch grounds the P-lead. Your video appears to have that backwards. Also, this video indicates that the mag rotor generates a voltage of thousands of volts in the coil. Actually, the magnet motion creates a voltage well less than 100 volts. The spark voltage is induced when the points open to break the primary circuit. And the mag can still be turning but NOT MAKE ANY SPARKS if the points aren't opening or are too corroded to conduct primary current.
Hi Jerry, you are correct. The spinning magnet creates alternating current across the primary circuit of the coil, creating its own magnetic flux. The sudden opening of the points collapses that flux and a high voltage current is induced in the secondary circuit. The points are mechanically timed to open at the perfect position (called E-Gap) right as the current is beginning to alternate. As you expect with anything mechanical, this "internal timing" can drift and improper E-Gap is a common cause for a no-spark magneto. Hard to get to this level of technical detail in a short video, but certainly, if anyone wants additional information on the operation of a magneto please feel to reach out! - Zach
Dude does not know that the magneto turns on when the p-lead becomes ungrounded. At first I thought that he misspoke when he said that the mag was grounded with the start switch turned to start, the first guy responded with a incredulous "oh really". He then started to describe that the ground check is to check that the p-leads was "not grounded". That confirmed that the dude does not know what he's talking about. The look on the middle guy's face while he's trying to bite his tongue says it all.
The "world famous director of maintenance".............
Wow! Great explanation! Thanks so much for the information. It’s extremely helpful to a beginner like myself to understand this stuff! Be well guys!
Glad it was helpful! Thanks for watching, Michael!
My plane (Beech 23, O-320 D2B) uses a shower of sparks for starting instead of an impulse mag. It sounds different when the engine is cranking or when you pull it through by hand.
Amazing explanation!!! Thank you so much
Glad it was helpful! Thanks for watching, Priscilla!
The P lead is to "ground out" the magneto so it won't be able to fire.
Yes, and this helps prevents accidental starts. Thanks for watching!
If anyone has watched NHRA drag races, same spark concept. For the guys had an F10, F20 or F30 IHC tractor or an old 2 banger Jonny Pop, (John Deere) same concept. Heck your lawn mower, as simple as it is uses magnets to create a spark, rather crude but still, its a magneto.
Great Video! Nice to see Zach! Is this video protected? I would like to request permission to use it in an Part 147 A&P Basic Training Curriculum...Please advise.
A simple way to avoid the kickback would be to do the mag ground check at 1700 rpm instead of at idle before shutdown. A lot of checklists (especially for fuel injected engines) specify around 1700 rpm and then mixture cutoff. Although I believe this was written to fully drain the fuel injector lines to prevent vapor lock, I'm sure it could be adapted to do a mag check before cutting the mixture. Does this sound right?
If the RPM is high when you cycle the mags off and on, you have the very real potential for an exhaust backfire which can severely damage the engine. That is why some POHs specify that if the ignition is turned to OFF accidentally during an after-start runup, you should let the engine quit and restart it normally.
It is definitely safer to do shut-down ground checks at low RPM, just do it quickly. It's not something I do every time I fly, but I try to do it a few times a month. Treating all props as if they are desperate to start is the only way to ensure prop safety - the shut-down mag check is just an additional safety measure. It's also nice to know that if you needed to kill the engine 'instantly', you could do so by turning the key to OFF (versus waiting for mixture idle-cut to burn off all the fuel.)
Great content, thanks! btw check your camera. I can see some white flashing lines from time to time. And maybe add one more lamp. It's little too dark.
Wow these guys know their stuff!
Wonderful. Good refresher for me.
Glad you enjoyed it! Thanks for watching!
Great explanation thanks learned a lot
More about mechanics!
The explanation of the magneto ground check wasn't really clear to me. What is the purpose, to dissipate the energy in the magneto or something else? I understand the process, but why? And if it's done right does it lessen the likelihood that the prop is hot? Thanks for a great series. I'm looking forward to your next one!
You're checking that the magneto ground actually works before somebody finds out the hard way.
Just for clarification - when you do a quick grounding check (key off/on) you are looking to see/hear that the engine starts to die. IF the engine does not start to die when you turn the key off, the mags are always hot when they should not be. Which means the engine could start inadvertently (during preflight or moving the plane etc.). As an example you could try this on your keyed lawn mower or snowblower if you have one.
Patrick C. Thanks this is a much better explanation for someone not knowledgeable (most pilots) to understand.
@@patonbike - Just thought I'd add to your comment. It doesn't necessarily mean one of the mags is always "live" as you said. It could also mean that since start up you were only operating on one mag (the mag you switched to) the entire time, so the other mag is not operating at all.
You want to see a reduction in engine rpm when you switch to each of the magnetos individually so you know that both mags are functioning together. You are also checking the P lead, or grounding system of the magnetos which is used to keep the mags from functioning. If the P lead (s) are not correctly connected, the engine could start up while hand turning the prop on the ground during maintenance or simply moving the prop during an inspection etc.
I had a mag go out on me over the water a couple of weeks ago on a local training flight! Crazy! You sure can't train for those types of failures.
indeed. as Russell said, 'glad you made it back" its funny how many pilots will acquiece and take off knowing 1 magneto had a 150 rpm mag drop during his check. thats all fine and dandy, until your one good magneto craps out on you, and your continued good health depends on that poorly running, last magneto. moral is not to compromise on a safety related item.
So when you do a run up, check both mags, and your RPM drops for both, does that also confirm the mags are grounded?
Ok, thats what i thought, thanks!
Sounds like you guys know how the magnet part works, but you don't have an idea of how the generated electricity is developed or works or the difference between voltage and current. The difference between the ground and hot, and does the ground kill the voltage or actually connect the ground side of the magneto to chassis. Does the ignition switch apply a ground to the hot side to kill the spark when set to OFF or does it actually connect the ground to the magneto when set to ON,
Is hot mag/prop why you use mixture to cutoff and not just ignition off, when shutting down?
Can't start with no fuel even if it were grounded/hot
Yes. The engine still requires a fuel/air mixture to start.
Great work BUT you did not explain AT ALL how to do a hot prop check CORRECTLY??
Wow amazing video thank u so much
Sorry to nit pick, but it's "magnetos" (plural) not "magneto's" (posessive).
not not picking at all - proper spelling = credibility
No, Magneto owns the plane. Its Magneto's plane.
@@StrokeMahEgo x-men unite!
in other words, the magneto turns your plane into a windmill to generate electricity and keep the engine running?
That's one way of thinking it! Thanks for watching! Fly safe!
I did a magneto check this morning on my C172 and found that one of the magneto was hot. Can I still go ahead and fly or should I get it check by a mechanic?
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So then why still need an alternator? And how come cars have alternators instead of magnetos, magnetos seem more efficient?
To charge the battery up after start up
But if you turn off the engine you can't turn it back on since battery is dead.
You hear these guys rambling on about a lot of nonsense. It really isn't a kickback issue caused by timing when doing a mag or ground check. What really happens when you turn off the sparks, the engine continues to spin and pump unburned fuel into the exhaust. When you turn the ignition back on, the fuel in the exhaust pipe is ignited by the hot exhaust from the running engine. A loud bang can be heard. Sometimes when people have a lot to say, they're just trying to sound smart but in reality, they really don't know what they're talking about.
Needs some graphics
I want to make sure my tea leaves are not grounded? Wh a t?
Magneto's reliable? with 500 hour tbo one can't hardy call that reliable.. a modern ECU works for thousands of hours with no problem.
until it doesn't.... plenty of cars die while driving due to ignition failure. I think dual redundancy is the real source of reliability, not necessarily the mags themselves.
Champion does recommend inspection of magnetos every 500 hours and overhaul every 12 years or 2000 hours. Our engineers are presently working on developing the next generation of piston ignition systems with the expectation of reducing service intervals.
Electronic ignitions also allow for weight savings (even with backup batteries) in addition to better power and economy. And can be integrated into a FADEC for real-time ECU adjustments.
I suspect magnetos remain in heavy use in aviation mostly because of certification and installation costs for alternatives.
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