This week we take on our first system on the show and we believe it is the first of many. Pilots do a magneto check before every flight and hopefully we give you some things to consider next time to you do your check!
This week Bobby and Wally discuss a system for the first time and believe it will be the first of many. Each time we fly we do a magneto check and as Wally says, he hopes we change the name to an ignition check. There are a lot more things we are checking besides the magneto and hopefully you learn a few things this week. Let us know what you think and please share the show with a friend. Thanks!
Welcome to behind the prop podcast where each week. We will bring you stories lessons and some tips from behind the prop. Please subscribe wherever you listen to podcasts pre show checklist microphones, check out check complete recording all channels checked and verified pre-show checklist complete tower Bravo. Tango papa is holding short ready for departure Bravo Tango Papa, you are clear for takeoff. Have a great show your clear for takeoff and Wilco Bravo Tango Papa.
What's up Wally? Hey bobby, how are you? I'm good. This has been a ton of fun doing the show. We've got a ton of topics to cover. Thanks for everybody who have taken time to submit a show idea for a free behind the prop coffee cup. We will be shipping those out and you probably already got him by the time. You're hearing this episode And we would love to hear more ideas if you have ideas for the show. Please don't hesitate to shoot us an email. I can be reached at bobby at behind the prop dot com and while it can be reached at Wally at behind. The prop dot com. Sin your show ideas and we will add them to the list. We've been having a lot of fun. Well, I think. I have while I have you been having fun. I've been having a blast. We had our first guest on a couple of weeks ago. We have more guests lined up in the future. This is Kind of I'll say reinvigorated an old guy who was looking for a new fun way to give back And I’m pretty sure it's doing the same thing for wall as well. This week is all about the ignition. System and a magneto check We've had ideas that we would do systems and things like that throughout spattering throughout the podcasts shows that we do and this is really the first kind of systems item. We're going to cover a feel like I’m way behind the power curve as two guys. Sit in a room. One of us knows a lot more about it than the other. And that would be Wally. But I think I have a view from fly school owner’s perspective on what things continuously kind of happen. How we think about it How things do get broken and get fixed. And while it has a view of a pl- airplane owner himself and things that he sees in check rides that we're to kind of run through today for sure so we're going to kind of give an overview of the way we think about the ignition system in a magneto. Check that we're going to talk about common things. We both see With pilots renters. Check right candidates in what happens that either throws them off or causes them problems. We're going to talk about some best practices as it relates to troubleshooting and resolving some of the symptoms that you may uncover and then we're going to tell you a little story that Might help you all be a better pilot moving forward while he gives us cause you do know a better than me kind of almost from ignition switch through the system kind of walk us through the way you think about the ignition system in the magneto check and then we can dialogue a little bit about how we do the magnet check. And what the checklist says. But let's start with an overview of the ignition system. I'm going to. I'm going to do my best to make this Extremely basic. I'm not an amp. I'm not a mechanic. But I do operate these airplanes and Hopefully I operate them safely. So you know on a check ride I am required to a private and commercial and required to cover three systems. One of the systems is engine or power. Plant is the way it's listed in the acs well within the power plant system There's a subsystem called the ignition system. That is You know usually when we think of ignition, we think of of starting the engine but in fact the ignition system is. What's igniting the fuel which is making the pistons within the cylinders which is eventually turning the propeller so the ignition system is constantly working within the airplane so the basically the components of the mcnish the ignition system are You know you've got the you've got the switch which we all have right in front of us. There's a starter which actually starts the airplane but once the airplane gets going. I and we're talking about traditional airplanes. We're not talking about an electronic ignition. Airplane We have a magneto system And the root word in magneto is magnet so basically, I’ve magnets turning around which are Providing power to the spark plugs which are igniting. The fuel air mixture was in within the cylinder.
Which is making the cylinder the pistons go up and down or side to side which is Eventually turning the propeller so we most airplanes. We have this thing that we do before we take off called magneto check and The one thing that we do is we you know. Most airplanes have tomatoes And we shall one might need off at a time and those reference normally his left and right correct. Correct that I guess for my what I’ve learned you know there's two magneto says each those magnetos have a line a wire that leads from them to each cylinder. Correct at two to each spark plug. He magnate goes to spark plugs. So each let's for demonstration purposes. Let's talk about a four-cylinder airplane so a four-cylinder airplane. We'll have to spark plugs on each cylinder so each magneto is providing power to force spark plugs. So basically when we do the magneto check were shutting off magneto. Which in turn is now shutting off for spark plugs so When we do a magneto check Typical four-cylinder like homer continental airplane is somewhere between seventeen hundred and two thousand. Rpm when we when we switched to one magneto, we're losing somewhere around one hundred rpm so we're losing about five percent power. Is the airplanes still running. It is if everything is working properly. Is it running smoothly. It is Will the airplane fly like this. Could you do this in the air. You could And in fact Some people are advocates for doing a mac. Check in the air But basically you were shutting off half of the spark plugs and each cylinder is now running on one spark plug and again we don't lose half the power we lose maybe five to seven percent of the power. Is that something that's noticeable. It's not but what we're doing is by doing that magneto check. We're checking a whole lot more than the magneto so by doing the magneto check core checking the hall integrity of the ignition system. So if I ever get to be king of world one of the first things. I'm going to do is. We're in a quick columnists and magneto check. And we're going to call it an admission system check and it's in fact. Some of the newer airplanes refer it to it as the ignition system chip. Check as opposed to the magneto check. I think what Younger pilots is if there's a problem during the magneto check they immediately attribute it to the magneto and They'll tax the airplane back. They'll go up to the mechanic and they'll say hey. The left magneto is bad. When in fact it could be a wire and most likely the most likely culprit is a spark plug. And one thing. I try to encourage Younger pilots to do is when you are speaking to maintenance people. Don't tell them what you think is wrong. Rather tell them what the symptom is. It's just like when you go to the doctor You probably don't go into the doctor and say a doctor. I have a. I've got a kidney stone. You may want to say hey. I'm I have pain in my back in. This is what's going on and you'll let the doctor make the diagnosis same. Same with maintenance. If you come in and you say I was doing my magneto check When I was in the left position the engine was running extremely rough. Okay let them make the diagnosis now. If you come in and tell them you got a bad mag most I my. I would venture to say that every mechanic is going to really say well. it's probably not a mag. It's probably a spark plug probably going to say right then in that moment. Did you try to clean the spark plugs. That's the first thing they're going to probably say And I think that's probably as you mentioned the first most common thing that we see in the magneto check rough running engine. That's the symptom the normal culprit first and foremost would be a fouled spark plug. Yeah, absolutely the problem that we have with these. Airplanes is on the ground. These engines run to rich.
So there's too much fuel that is not being burnt so the that fuel turns into carbon which builds up on the sparkplug and it makes the spark plug either less efficient or totally inefficient Where it's not firing at all And if you haven't listened to any of mike bushes podcasts or any of his webinars. I would highly recommend one thing that the You know the whole COVID thing with Oshkosh being canceled This past year I watched a lot of virtual seminars. I'm a big fan of Mike Busch. He's a The maintenance guru for general aviation airplanes and I highly recommend any of his things but he does talk a lot about this and a lot of what I had been saying. My was little bit reaffirmed by Some of his Some of his ideas and thought process so the point is that taxing around on the ground. We're really running these engines to rich and so the fuel goes unburned and it. It does deposit carbon on the spark plug. And that's what happens is so now. When are we going to see this. If we have one spark plug of a cylinder that is not running efficiently under normal circumstances on both. Were never going to know it. Because the other spark plug is working just fine So where we're going to see. It is when we go to the mag check when we shut off that good spark plugs on a given cylinder and now the only one that's running is the one that's running that that may not be working at all or may just be inefficient and the reason for the rough engine is basically the engine is unbalanced one cylinder on one side that is working You know maybe at one hundred percent and the other one at the other side may not be working at all or maybe working at a lesser percentage. So we don't have the equal force of the pistons Balancing the engine out. And that's where we get the rough running engine so again this presents itself in what we call the magneto check and it's not a magneto problem at all. It's a spark sparkplug problem and easily fixable and a lot of the airplanes have a procedure in there for cleaning the carbon. The spark plugs. So I would encourage you to check your h. Or if you don't have anything in the in the POH check the With your mechanic or the flight school or the f. b. o. that you're renting the airplane from so we go through this cleaning process and then we do another matching. So we're checking the whole ignition system again and we don't have the rough running engine we we've probably cleaned that carbon deposit off. All things are good and we move forward. I've seen a lot of different things happen. We'll what are some other common things we might see We've talked about the wires. The wire would act exactly the same because it wouldn't beginning fire to that system. Meaning that spark plug so we would have that same imbalance in the engine but we wouldn't be able to clean the wire. Obviously if the wires bad right we're never going to be able to solve that from the cockpit as a as a pilot I've seen I’ve seen this. We're actually a cylinder presented itself for the first time that we had a cylinder issue. I think it's been within the last year. We had a ring that that had come off cylinder that we didn't know we weren't aware of it but it presented itself in the magneto check in the and here. We are the cleaning process. Obviously, he's not going to replace the ring on a cylinder but we have the same rough running engine very similar symptoms. Some that have been around a long time was. I can't believe they're unable to clean that right. Well that's a. There's a point where you can't clean and the cylinder actually was the problem when we were placed the cylinder and we went on any other thoughts or ideas that we would see common things that we might uncovered during a magnetic check. Now that that That is the most common. And what. I hear when I Discussed this with applicants on check. Rides is I will present this situation to them and They'll say well. The magneto is fouled. Well it's not really the magneto It's the spark plug now in. The big scheme of things are we. Is it just terminology.
Thing or You know did we not understand the system. Probably don't understand the system Do we need to understand the system to safely. Fly the airplane. No I don't. I don't think we do it. Sure helps things and as an aircraft owner cheer helps when you're when you're talking to your mechanic but One story That all share. I had an applicant and Young lady coming in for a private pilot check ride and She did a really nice job. Lou flew the airplane very well. The ground portion went really well but she told me the story about how She was prepping for her check. Ride and I. It was springtime so that who was getting warmer and she called her cfi and she asked her CFI. He would mind if she brought her daughter along with her for this particular flight. They were doing their prep right before the check ride so she was You know far along in her private pilot training and the agreed to let her bring her daughter so she came out and they got an airplane. They're in a one seventy-two and End model one seventy-two. If I’m not mistaken and They taxied out and they did their run up. Everything appeared fine and They started their offer all and she said to her instructor. The airplane doesn't feel right it. It doesn't feel like it's right It's making enough power and his comment to her was well. You've got your daughter in the back and you know she's one hundred pounds and you're just not you're not used to that and she said okay and so they took off and During the climb out she reiterated her instructor that it just didn't feel right. It didn't the airplane didn't seem to have the power that it normally has and his comment to her was well. It's you know it's also getting warmer. You got an extra hundred pounds and last time you flew. It was fifteen degrees cooler so we have less performance and she said well okay all right and they kept flying so Just think about that for a little while and think about what you might think might have been the culprit. There was there was a slight issue and It all turned out fine because obviously she came back and earned her private pilot certificate. Just a couple weeks after that. But I’m going to leave that there and Let you guys think about that. I believe wall. He's going to give you the answer to that story next week on our show. Yes, and if you have some ideas about what might be the problem Just shoot me. An email at Wally at behind the prop dot com. So the other common thing we did we did mention it. Was that the magneto itself could be bad and I. I challenge people. Because I’ve done some done a little bit more systems digging as the fly school owner than I ever did as a private pilot or instrument pilot and I don't think many people know what a magneto looks like it and I don't think I want you to know what it looks like when you pull out of the box, I want I want you to go on the google somehow some way and find some pictures of a magneto and what it looks like. It's actually a spinning item. It spinning the whole time. And then there's four leads on a four-cylinder engine there's four leads and as that magnet goes by those leads it creates a spark which travels down that wire to the spark plug in essence creating a fire and the cylinder of the piston works inside of that cylinder The timing in the magneto could be office. Well I think Too often. If I bought a magneto every time someone told me that a magneto was bad or as you said a magneto was fouled broke Because it's not necessarily. The magneto is broken completely. But that timing can be fixed. And that's where you might see an unusual drop in one side or the other. So I might have that hundred and twenty-five rpm drop in one side and one hundred eighty in the other that would that would indicate. There's probably something a little off a little. Askew could be the magneto and as a flexible owner. I would challenge you to not say both magnetos are bad. Come in and talk about the symptoms on the left. I had a hundred. Rpm drop on the right. I had one hundred eighty. Rpm drop Is that it should be looked at by a professional. And I would say this to if you're out doing your run up and you see that Everyone of us has a cell phone with us and Taken a video of that mag check To actually showed the mechanic.
Because I I’m not I’m not stupid. I know as a pilot. I come in and I tell mechanic stupid things and this news. I walk away. They're rolling their eyes at me But video videos really helpful Anytime I have situations like that. Actually use it with our airline you know strange head-scratching indications it's really easy. Just pull out your eye powder pull out your phone and take a ten-minute clip. I mean a ten second video clip of what it's doing and Usually you can. You can email or text at the somebody in that. That picture is worth a thousand words. No doubt and that's a great tip I would highly recommend that for anything that you see if you Happened to see a problem with a cylinder on a on a in the inflight once hotter than the other take a video of that it could be an indicator. It could be a real problem but it's going to help your flight school and your mechanic by having that information as you saw it readily available for them so I guess the last best practice I think I share Wally is. There's I’ve had a lot of cfi's come through here and the and those cfi's had varying personal minimums right. I've had cfi's that if it was if it was a fifth more than fifty delta. They weren't going to fly that aircraft for the day. Some have a hard line on the POH. Which I would be my hardline. Probably unless I heard something right what would what would you. Would you have a pilot create personal minimums around what they're going to see and do with magneto jack. If I can't clean it, I’m not going. I mean that's a that's a pretty simple one but what would your thoughts be from a mentor to some of these younger pilots on how you would reflect on a magneto check. That might not go just right. I would go by the numbers in the p. o. h. And obviously if it's if it's running rough the engine should run smooth so a rough a rough running engine To me means it's an unbalanced engine You know these the oh most of these engines are oh three twenties or three sixties or maybe an I o the those. Those letters actually mean something if you have an I do. The I stands for injected. It's means its fuel injected airplane Not going to be any carburetor. He there's no carburetor If it's just an oh My one Seventy-two as an oath three twenty stands for opposed and what that means The root word of opposed his opposite the cylinders are opposite of each other and the reason that the engines win running Properly run smooth. Is that the Action of the pistons are counteracting each other their opposite of each other. So if one piston is not Operating properly That causes basically that engine to be unbalanced and that's what causes a rough engine rough feeling engine so don't feel obligated to go. That's kind of. I think are tip to you right as is half someone else. Take a second look. Have someone jump into a run up with you and make sure that they do the magneto But don't just assume that it's just one spark plug make sure someone looks at it still rough And you can't clean it by the by the flight. Schools or the FBO does procedures Hopefully learned a little bit about the ignition system. Today we're going to do more systems like this pieces at a time. And hopefully as people want to learn more about systems and come back and listen to all these episodes and learn more. Today I happened to have learned something myself which is which is good If you want to learn more about the ignition switch the system in general. There's all kinds of information in the airplane flying. Handbook and your p. o. h. Those are the two places to look. I anything to wrap with today while they know that you made a great point bobby and talk about the airplane flying handbook. There's so many great resources out there. I remember as a new private pilot many years ago. sitting at home sitting up in in in my bed with the tv. On and I. I reached down and I found my f. a. r. a. m. and I started reading the aim and I just remember it was a light bulb moment in my flying career. I remember thinking. Oh my gosh. There is a lot of good stuff in here. And I still to this day. I so many resources out there.
But I go back to the airplane. Flying handbook to some of the books boy. If you want to learn the ignition system. It's not an it's not a six-chapter dissertation on how the ignition system works. It's about a page in an act page and a half. It's actually fairly easy reading. And it's really good stuff yet. Used those books. We talked about the aim a couple of weeks ago. It's a wealth of information and to too few too few people actually open it up and really read it. Yeah, but it's got a lot of really good information in there with that. We'll wrap as always fly safe and stay behind the prop.
That's the show. Bravo Tango Papa, we are clear the active Runway and would like to taxi to park Bravo Tango Papa taxi to parking great show. Have a nice day. Taxi to park. Thanks you to Bravo Tango Papa. Thanks for listening to Behind The Prop please follow us on social media @BehindTheProp or visit our website at www. Behind the prop.com until next week. Fly safe everyone.