I am a student pilot currently just working on my PPL. Thank you so much for doing such a great explanation of the magnetos! I am fairly mechanically inclined, but have never actually seen a magneto other than being mounted in the plane. I understood the concept of how and why they worked but your video helped reinforce that learning and giving me a deeper understanding of the actual how and why.
I remember when a magneto went stupid in my dad's plane. We were on a cross country up into a remote grass airstrip for some airplane camping, and we landed for some fuel. After refilling the plane, he did the mag check and on one side the engine ran really rough, as if it was only running on three cylinders. Fortunately there was a mechanic on hand and our trip was only delayed by 3-4 hours. Moral of the story... even if you were flying half an hour ago, do the preflight and engine runup again. Just in case.
I'm training to be an AME and just studying this for a test. You did such a good job explaining that P-lead and condenser compared to my textbook, this was extremely helpful!!!
@@williammickelson403 pretty sure you need to be able to troubleshoot ignition systems. This includes inspecting mags (like the breaker points, p-leads) and mainly timing the mags to the engine, or so my engine teachers say 🤷♂️
Second year student Aviation Technology here (AMT Cat A holder/studying for Cat B). This video helped me A LOT on understanding how a magneto works and what components it holds. Even better so then they explain in school/my course material! Just found your channel, great work! Thank you very much!
Just the way it failed it was working on and off. The way the airplane had been acting lately I had suspected it for a while, but could never duplicate any problems on the ground with an A&P around until finally it was totally dead and we just pulled it off.
@@paradiseroad6405 And if one mag is bad the engine is only running on one plug not both! In mag check if you turn off the bad mag there won't be a drop because it's already not running on 2
Magnetos have a special memory for me. I was in my magnetos class when the first plane hit the WTC on 9/11. I watched it all on TV for a bit before I went to lab. I was overhauling one of these when the towers fell. I was also a pilot and my wife couldn't reach me so she was freaking out a bit since they grounded every plane in the country.
We were doing a 100 hour on a Cess. 172 R model and the left mag pulled a wire off. The A&P stripped the wire threw a new loop on it and we cowled it’s. Test run as im you guessed what’s going to happen . We started it up and did a run up. Right was fine but the left would imidiatly kill it. Well what we didn’t know was that the wire we stripped was 2 in 1. So after we separated the 2 and re wired it ran flawlessly. My point behind the strong. CHECK YOUR WIRING ! then ....DOUBLE CHECK ! Lol. Thanks great post.
When you change the brakes on your car, you just let the caliper hang by the brake line, don't you? I was so distracted by the back of the housing flopping around hanging by the condenser wire, wondering when that poor solder joint was going to give up the ghost that I couldn't concentrate on what you were saying. Interesting video though, I definitely learned something so thanks for that!
I'm guessing removing the P lead but that doesn't answer the how to start it. Just more how to make it not stop. Also, I didn't quite understand the coil and magnet generating power part. I wonder if a diagram or animation of this would help viewers understand it better? Great video btw!
did you watch the video? the question I was replying to was "what would you do if you were out in the Everglades and lost your keys, but needed to get home and make your engine run?"
The P-Lead holds your engine off via the ignition. If you disconnect the P-Lead, you essentially disconnect the ignition "Off" switch and then you can manually push the prop over to start it after pushing mixture full rich. Look up some safety videos some time, they show it happening unintentionally. Scary Stuff.
A forum mentioned that the Right mag is disabled by the ignition switch when in the START position. This is apparently a safety feature due to the Right mag having no impulse coupler, and thus, not the best suited (and can cause damage) for initially starting the engine. If this is true, does that mean you should first only disconnect the Left mag P-Lead, and once the engine is running (after hand prop), then remove the Right mag P-Lead to allow the engine to run on both L & R Mags. Also my instructor never explained fully the reasons for checking deadcut (thats what he calls it). Am i right in thinking that this is simply to ensure each mag grounds itself via the P-Lead when switching between the Right and Left Mag. Does the ignition off position ground both the L&R mags?. Lastly, if switching from Both to the Right Mag you experience no RPM reduction, would this suggest that either the Right Mag P-Lead was not grounding properly or that the ignition switch itself was faulty?.
Every mag ive ever seen or heard of would have been involuntarily thrown at the ceiling if you were holding it in your hand and messing with the shaft like that. The spark is usually much much stronger than what it seems your working with. I would recomend no one try this at home. (Maybe the airplane stuff has such less power? I doubt it we are still trying to ignite gasoline in a cylinder at a specific time with less compression than a more modern engine)
Basically, if you worked on your own pre-electronic ignition car, you would be familiar with this functionality . Points, condenser, rotor, and cap from the car; magneto from your lawnmower.
There is not a coil of wire on two sides...........there is one coil wrapped with another coil over it..........fine wire over thick wire...........it steps up the voltage and gives you 10,000 volts to jump a sparkplug..
I was fine with you saying that the magnetos produced "sparks" instead of electricity until 4:00 when you started talking about the hot spark wearing down the distributor. There is no spark inside the magneto, and the damage is entirely from friction.
If you take a look inside the distributor on the mag (i.e. cutaway) you will see the sparks (electricity) jumping to the posts in the distributor to flow through each wire to the spark plug. Those sparks (high temperature) caused local areas on the posts to change state and develop that build up that it pretty high resistance and would not allow the electricity to flow through to the plug wires and to the plugs.
I am not yet a Flyer but I am mechanically inclined......I guessed that you would remove the kill circuit(P leads) and hand turn the prop............then quickly get the hell outta the way
Magnetos produce electricity not sparks. The spark is produced by the spark plug. The magneto connects to the spark plugs and sends electricity at a precise moment and to the precise spark at a given time.
Why in the world not replace these early 1900s artifacts with solid state. Last car I had with a point and distributor cap was a 1964 American Rambler with a flat head switch.
If an aircraft suffers a complete total electrical power loss the solid state system fails also. Magnetos are completely autonomous and require nothing but the engine turning to make spark. A total aircraft electrical failure will not lead to an engine failure......
remove the primary leads to both magnetos, master on ,rotating beacon,prime 2x have a qualified person at the controls,call contact,use flats of hands and rotate in direction of rotation to the left,step back and continue stepping back hahahaha.A screwdriver on an ignition,might be illegal to the administrator.You guys remembered the day mr denver crashed,I saw a picture of him with a pair of pliers that morning on the long ez.so nawing and hacking I kinda frown upon as a licensed wanta be airframe powerplant mech,give me a motorcycle or car and truck,thats a different story,it just takes time and effort,dont get mad,its sad.
flexairz It is used for reliability reasons. When a battery on a car dies the engine dies too, the spark is provided by the battery. When the engine on an aircraft dies the engines still works, magnetos create their own spark.
It isnt just magnetos. The average modern farm tractor engine is light years ahead of any GA recip engine technology wise. If it weren't for FAA regs and insurance liability issues, the average Lycoming or Continental GA engine would sell for $3000 tops, not $40k and up.
Johnny Appleseed Correction: the battery is primarily intended to power the starter. It can also power the electrical system for a while with the engine off. The alternator is what's intended to power the electrical system and recharge the battery after starting. Same as in your car.
@@6h471 , great reply thank you (I know this is a 2 year old comment). I see this "old technology" complaint all the time regarding GA engines. There is a REASON why "things are the way they are" and YOU perfectly explained it. The costs involved in bringing a up to date general aviation engine are HUGE but the demand for general aviation has been in a downward spiral for decades now. And I do understand the "cost of all things related to flying" is a large cause of the decline in General Aviation from the peak years. But nobody is going to spend tens of millions of dollars, or more, just so I can have a modern cheap engine. There just isn't a large enough profit margin anymore due to the exact reasons YOU noted; insurance liability issues and cost of certification through the FAA regulations.
I am a student pilot currently just working on my PPL. Thank you so much for doing such a great explanation of the magnetos! I am fairly mechanically inclined, but have never actually seen a magneto other than being mounted in the plane. I understood the concept of how and why they worked but your video helped reinforce that learning and giving me a deeper understanding of the actual how and why.
Glad it helps! Fly Safe!
1:06 I got a chuckle at that engine part pun. "so for starters, this is a magneto" lol
I remember when a magneto went stupid in my dad's plane. We were on a cross country up into a remote grass airstrip for some airplane camping, and we landed for some fuel. After refilling the plane, he did the mag check and on one side the engine ran really rough, as if it was only running on three cylinders. Fortunately there was a mechanic on hand and our trip was only delayed by 3-4 hours. Moral of the story... even if you were flying half an hour ago, do the preflight and engine runup again. Just in case.
I'm training to be an AME and just studying this for a test. You did such a good job explaining that P-lead and condenser compared to my textbook, this was extremely helpful!!!
why do you need to know how a magneto works to be an ame? seems a little out of place
@@williammickelson403 pretty sure you need to be able to troubleshoot ignition systems. This includes inspecting mags (like the breaker points, p-leads) and mainly timing the mags to the engine, or so my engine teachers say 🤷♂️
yeah for some reason i was thinking AME as Aviation Medical Doctor. I now know it means a mechanic lol
Disconnecting the "P Lead" would do the trick I guess :)
Second year student Aviation Technology here (AMT Cat A holder/studying for Cat B). This video helped me A LOT on understanding how a magneto works and what components it holds. Even better so then they explain in school/my course material! Just found your channel, great work! Thank you very much!
Disconnect the small wires on the mag. So it keeps running. Great videos!!
Cool video...but here's another pop quiz question: why did you get a 100rpm drop when you ran it on the other magneto, if this one was dead?
Just the way it failed it was working on and off. The way the airplane had been acting lately I had suspected it for a while, but could never duplicate any problems on the ground with an A&P around until finally it was totally dead and we just pulled it off.
...because firing one plug in the combustion chamber instead of both slows the flame propagation and the engine slows down slightly...
@@paradiseroad6405
And if one mag is bad the engine is only running on one plug not both! In mag check if you turn off the bad mag there won't be a drop because it's already not running on 2
Magnetos have a special memory for me. I was in my magnetos class when the first plane hit the WTC on 9/11. I watched it all on TV for a bit before I went to lab. I was overhauling one of these when the towers fell. I was also a pilot and my wife couldn't reach me so she was freaking out a bit since they grounded every plane in the country.
We were doing a 100 hour on a Cess. 172 R model and the left mag pulled a wire off. The A&P stripped the wire threw a new loop on it and we cowled it’s.
Test run as im you guessed what’s going to happen . We started it up and did a run up. Right was fine but the left would imidiatly kill it.
Well what we didn’t know was that the wire we stripped was 2 in 1.
So after we separated the 2 and re wired it ran flawlessly.
My point behind the strong. CHECK YOUR WIRING ! then ....DOUBLE CHECK ! Lol.
Thanks great post.
Great video i wish my instructor at school explained it so well
Always happy to help!
When you change the brakes on your car, you just let the caliper hang by the brake line, don't you? I was so distracted by the back of the housing flopping around hanging by the condenser wire, wondering when that poor solder joint was going to give up the ghost that I couldn't concentrate on what you were saying. Interesting video though, I definitely learned something so thanks for that!
Lol, that mag is just for instruction. Being that I'm not an A&P, if I take something apart, it won't ever go back on the airplane.
Lol. That thought crossed my mind too, but wasn’t so distracted that I wasn’t enjoying the crap out of this video.
disconnect p lead and hand/rope the prop to start
Disconnect the P lead and hand prop the engine.
Good video. That's why we pre-flight!
Amazing vid
Great video!
Also disconnect the p lead and you can run it without the key am I correct for that question?
I'm guessing removing the P lead but that doesn't answer the how to start it. Just more how to make it not stop. Also, I didn't quite understand the coil and magnet generating power part. I wonder if a diagram or animation of this would help viewers understand it better? Great video btw!
That was a really informative and useful video - thanks!!
pull the P lead and keys don't matter.
Cool video. Thanks for the visual explanation! It helps to understand when your in groundschool.
Glad it helps! Share us with your friends on FB and around the airport!
Remove the P-Lead and the Mag will not short to ground (i.e. override the key)
Pop off the p-lead and hand prop the engine
Dittos.
if you lost the key, you can't turn the ignition.
did you watch the video? the question I was replying to was "what would you do if you were out in the Everglades and lost your keys, but needed to get home and make your engine run?"
The P-Lead holds your engine off via the ignition. If you disconnect the P-Lead, you essentially disconnect the ignition "Off" switch and then you can manually push the prop over to start it after pushing mixture full rich. Look up some safety videos some time, they show it happening unintentionally. Scary Stuff.
A forum mentioned that the Right mag is disabled by the ignition switch when in the START position. This is apparently a safety feature due to the Right mag having no impulse coupler, and thus, not the best suited (and can cause damage) for initially starting the engine. If this is true, does that mean you should first only disconnect the Left mag P-Lead, and once the engine is running (after hand prop), then remove the Right mag P-Lead to allow the engine to run on both L & R Mags.
Also my instructor never explained fully the reasons for checking deadcut (thats what he calls it). Am i right in thinking that this is simply to ensure each mag grounds itself via the P-Lead when switching between the Right and Left Mag. Does the ignition off position ground both the L&R mags?.
Lastly, if switching from Both to the Right Mag you experience no RPM reduction, would this suggest that either the Right Mag P-Lead was not grounding properly or that the ignition switch itself was faulty?.
Every mag ive ever seen or heard of would have been involuntarily thrown at the ceiling if you were holding it in your hand and messing with the shaft like that. The spark is usually much much stronger than what it seems your working with. I would recomend no one try this at home. (Maybe the airplane stuff has such less power? I doubt it we are still trying to ignite gasoline in a cylinder at a specific time with less compression than a more modern engine)
where's the link for the "under the cowl" video?
Basically, if you worked on your own pre-electronic ignition car, you would be familiar with this functionality . Points, condenser, rotor, and cap from the car; magneto from your lawnmower.
One question. If you turn the ignition to just the left magneto. Does it turn off that magneto or does it turn off of the right magneto?
This was a great video. Thanks for all you do!
Glad it helps! Be sure to share us with your friends on facebook and around the airport!
Nice use of the seatbelt
Great eplanation keep it up mate
There is not a coil of wire on two sides...........there is one coil wrapped with another coil over it..........fine wire over thick wire...........it steps up the voltage and gives you 10,000 volts to jump a sparkplug..
...yep...it's a transformer...
cut the p line. no free lunch though. you will have to starve the plane of fuel to stop the engine.
How do you check-out the Capacitor &/or Coil using your multimeter ? My Mag is grounded at the "P" lead & not firing . , , Help !
If it's grounded a the P lead it's not going to spark.
Remove the P-lead wires and start up the engine manualy.
know nothing about aircraft electrical stuff but from what you said.. remove p leads .. now am i ready to fly?
If the p leads break or are disconnected and the prop turns the engine will start (assuming there's also fuel flowing)
Would you check the other magneto for wear/ issues at this point?
I was fine with you saying that the magnetos produced "sparks" instead of electricity until 4:00 when you started talking about the hot spark wearing down the distributor. There is no spark inside the magneto, and the damage is entirely from friction.
If you take a look inside the distributor on the mag (i.e. cutaway) you will see the sparks (electricity) jumping to the posts in the distributor to flow through each wire to the spark plug. Those sparks (high temperature) caused local areas on the posts to change state and develop that build up that it pretty high resistance and would not allow the electricity to flow through to the plug wires and to the plugs.
Disconnect the P lead and hand swing the prop.
I am not yet a Flyer but I am mechanically inclined......I guessed that you would remove the kill circuit(P leads) and hand turn the prop............then quickly get the hell outta the way
Derek Burkett correct, but make sure someone is on the brakes.
Will there be ANY RPM drop during a R-L Magneto check when ‘no load’ on the engine is present? (E.g. Prop is not installed)
Magnetos produce electricity not sparks. The spark is produced by the spark plug. The magneto connects to the spark plugs and sends electricity at a precise moment and to the precise spark at a given time.
Pop off the p-lead and hand crank the prop
disconnect pea lead / how big is your engine
During preflight its happened to me engine didn't shut off but really rough running...
In that case, you can try leaning and running the engine at high rpm for like 10 seconds or so. If that doesn't fix it... well...
take off the mag test wire.
Why in the world not replace these early 1900s artifacts with solid state.
Last car I had with a point and distributor cap was a 1964 American Rambler with a flat head switch.
If an aircraft suffers a complete total electrical power loss the solid state system fails also. Magnetos are completely autonomous and require nothing but the engine turning to make spark. A total aircraft electrical failure will not lead to an engine failure......
...how much do three alternators weigh compared to two magnetos?...how much power does it take to run three alternators compared to two magnetos?...
install power to side of the mag and turn the prop over the engine should start up dont forget the electric fuel pump if you have one
You should order a new mag
The coil is probably internally shorted..
...it's probably a bad condenser...I found out the hard way about bad condensers many years ago...
What he said. But if you want to have some lolz, just take off the wheels and leave the aircraft sitting on some milk crates. Oo
remove the primary leads to both magnetos, master on ,rotating beacon,prime 2x have a qualified person at the controls,call contact,use flats of hands and rotate in direction of rotation to the left,step back and continue stepping back hahahaha.A screwdriver on an ignition,might be illegal to the administrator.You guys remembered the day mr denver crashed,I saw a picture of him with a pair of pliers that morning on the long ez.so nawing and hacking I kinda frown upon as a licensed wanta be airframe powerplant mech,give me a motorcycle or car and truck,thats a different story,it just takes time and effort,dont get mad,its sad.
Yeah give your AP a six pack of beer and five bucks what the hell.
Nice video, happy to support other aviation channels, see ours.
The nick eh 30 putto song :v
Hand prop it
Magnetos, 1930's technology in 2017...
flexairz It is used for reliability reasons. When a battery on a car dies the engine dies too, the spark is provided by the battery. When the engine on an aircraft dies the engines still works, magnetos create their own spark.
It isnt just magnetos. The average modern farm tractor engine is light years ahead of any GA recip engine technology wise. If it weren't for FAA regs and insurance liability issues, the average Lycoming or Continental GA engine would sell for $3000 tops, not $40k and up.
Johnny Appleseed Correction: the battery is primarily intended to power the starter. It can also power the electrical system for a while with the engine off. The alternator is what's intended to power the electrical system and recharge the battery after starting. Same as in your car.
@@6h471 , great reply thank you (I know this is a 2 year old comment). I see this "old technology" complaint all the time regarding GA engines. There is a REASON why "things are the way they are" and YOU perfectly explained it. The costs involved in bringing a up to date general aviation engine are HUGE but the demand for general aviation has been in a downward spiral for decades now. And I do understand the "cost of all things related to flying" is a large cause of the decline in General Aviation from the peak years. But nobody is going to spend tens of millions of dollars, or more, just so I can have a modern cheap engine. There just isn't a large enough profit margin anymore due to the exact reasons YOU noted; insurance liability issues and cost of certification through the FAA regulations.
@Darren Munsell How many batteries are you going to carry then? 3? 1?
🤔Beware!!! what u buy on eBay.
😂
Well, the condenser is bad just cause you say it is? What about test? Points a little burnt? Ok, complete failure, wait a minute…