I only do a mag check before the first flight, if I go land somewhere, then take off , I dont do it again.
From now on that will change.
Was flying my 182 in Costa Rica, its flying better than before, super smooth and quite (new muffler) hands off too.
Since the first flight left mag drop was a bit higher than what I liked it, I called the mechanic and he told me to bring it whenever I can, 5 flights later, I am near his shop and decide to fly there, also because I needed a new CHT probe installed, and the nose gear strut was a bit low.
He fixed everything and I asked him, to just come and see the mag drop.
When performing the test the engine quit, it did quit every single time.

Mag was removed, we opened and it is full of metal, the bearing had failed.
On the last flight it felt a bit rough, jus a bit, we were flying formation making videos so I was more concentrated in watching lead plane.
Landed and found out the restaurant we were going was closed, mechanic shop was 20 NM away,so I took off (no mag check) and flew there.
Lesson learned, DO THE MAG CHECK, also they can fail even at 20 hrs since overhaul.

I was bummed because was not going to be able to fly the rest of my stay, but fortunately someone had a Bendix mag from a O 520 Continental that will lend it to me.

It depends, but generally, I do one mag check per flying day. Redundancy of essential systems is why these things have two totally independent ignition systems.

Some days at work, I’d have five, six or more stops. Lots of those in places where getting a mag and mechanic delivered would be tough.

The bigger issue I see with mag checks is prop damage, which can be mitigated by proper pilot technique, but I often see pilots in backcountry settings doing pre flight run ups which make me cringe.

Magnetos are amazingly durable, all things considered.

MTV

I can attest personally to the redundancy of mags. Not recommended and those with better sense would have quit, but I flew two week or fifty hours on one mag at 200' AGL over both open country and Class B congestion on one mag. Brenco Aerial Patrol did maintenance on a budget. Mike will nail me because I could have hurt innocent people in cities, but I really needed the job.

2 Mags are redundant but performing a mag check after each engine start takes a few seconds and is part of my go no decision before taking off. Having a modern engine monitor allows a lot more information besides just a faulty magneto. I have had a mag fail early in the engine life - around 100 hours. It ran just fine that morning. Failed on the afternoon flight. Doesn't happen often either but nor do engine outs. I think it is also just good to have the engine at 1700 RPM for 20-30 seconds before making a takeoff just to check oil pressure/gauges and hear that it sounds good rather than making the call on the roll. As for the prop damage during the run-up I perform it on the taxi at slow speed so I don't suck a rock into the prop.

I am not flying commercially where I am making 5-6 stops a day either - well unless I am doing some serious strip bagging. Maybe I would feel different making that many stops. For me doing a run-up before each flight is just another part of redundancy - Which is what aviation safety is all about.



Josh

Good post and part of why I like my Horizon P 1000 tachometer with blinking red light if a mag has a problem. I have 4 Bendix mag's right now---two with some age that I'm running and two on my spare Pponk. Still I keep tormenting myself with putting a Surefly SIM on since it seems like a good idea but can still have problems.

I usually on check first run of the day on a rolling mag check with the cub. It is important to have proper 500 hour inspections and proper overhaul of your mags done at recommended time interval. Any time you see a noticeable drop in RPM at mag check just stop and figure out what the cause is. A proper all cylinder EGT/CHT will pay for itself in fuel and diagnostic matinance cost i the first 500 hours. The new electronic mags are no guarantee of problem free flight, buddy just had his fail at 20 hours while breaking in his new IO550. If you fly remote it is hard to beat a Bendix mag, seem someone has one laying on a shelf or on a plane waiting parts.
DENNY

I do one run up per day, unless something feels off

When you did your run up what how did your EGTs compare between L & R mag?


Also benex all day

Had a mag start to let go on my IO520, it had slicks when I bought it, I swapped over to bendex, ain’t nobody got time for slicks

mtv wrote:It depends, but generally, I do one mag check per flying day. Redundancy of essential systems is why these things have two totally independent ignition systems.

Some days at work, I’d have five, six or more stops. Lots of those in places where getting a mag and mechanic delivered would be tough.

The bigger issue I see with mag checks is prop damage, which can be mitigated by proper pilot technique, but I often see pilots in backcountry settings doing pre flight run ups which make me cringe.

Magnetos are amazingly durable, all things considered.

MTV

That’s not been my experience

Engine attached stuff wise, mags crapping out are up right there with dry vacs

If remote, you have the engine run ruff, or your engine instruments looked off, or the engine just didn’t feel like it normally does, would you not do a run up? and if one of your two mags was bad would you still fly?

motoadve wrote:Since the first flight left mag drop was a bit higher than what I liked it,

On the last flight it felt a bit rough,

,so I took off (no mag check) and flew there.

I don’t typically check my mags on subsequent flights when the turns are quick. However, that is when the engine is behaving normally and my engine analyzer shows me the normal EGT fingerprint of dual mag operation. I wouldn’t characterize the situation described as something reassuring me of normal engine function.

Squash wrote:

motoadve wrote:Since the first flight left mag drop was a bit higher than what I liked it,

On the last flight it felt a bit rough,

,so I took off (no mag check) and flew there.

I don’t typically check my mags on subsequent flights when the turns are quick. However, that is when the engine is behaving normally and my engine analyzer shows me the normal EGT fingerprint of dual mag operation. I wouldn’t characterize the situation described as something reassuring me of normal engine function.

That.

After flying medevac for years, I just don’t screw around with stuff.

Unless me staying there and waiting for part, or hitching a ride out, is going to put me at a greater risk due to conditions (also lots of simple sat messaging solutions these days if out of walking or phone range) I’m not going to launch over dense trees with a sick plane, especially since I really like myself, my plane, and since my certificate is how I keep my fridge stocked with good food

We’ll, not really, I normally go out to eat lol

NineThreeKilo wrote:

mtv wrote:It depends, but generally, I do one mag check per flying day. Redundancy of essential systems is why these things have two totally independent ignition systems.

Some days at work, I’d have five, six or more stops. Lots of those in places where getting a mag and mechanic delivered would be tough.

The bigger issue I see with mag checks is prop damage, which can be mitigated by proper pilot technique, but I often see pilots in backcountry settings doing pre flight run ups which make me cringe.

Magnetos are amazingly durable, all things considered.

MTV

That’s not been my experience

Engine attached stuff wise, mags crapping out are up right there with dry vacs

If remote, you have the engine run ruff, or your engine instruments looked off, or the engine just didn’t feel like it normally does, would you not do a run up? and if one of your two mags was bad would you still fly?

Ummm, is that intended to be insulting, or???

If I ever had a rough running engine ANYWHERE, I figured out what the problem was before I launched. A brand new Cessna 185 fouled injectors frequently, and that thing shook like hell when that happened, and it happened frequently for over the first 200 hours. I got good at landing on a lake, pulling the top cowl, finding the offending injector and cleaning it.

I’ve cleaned a LOT of spark plugs due to rough running engines.

I’ve never had a magneto failure, either in a work or personal airplane, but writing that will likely jinx me now.

There’s this thing called “maintenance” , which, when carefully and regularly completed will prevent MOST magneto problems.

Or, maybe I’m just lucky…..

MTV

mtv wrote:

NineThreeKilo wrote:

mtv wrote:It depends, but generally, I do one mag check per flying day. Redundancy of essential systems is why these things have two totally independent ignition systems.

Some days at work, I’d have five, six or more stops. Lots of those in places where getting a mag and mechanic delivered would be tough.

The bigger issue I see with mag checks is prop damage, which can be mitigated by proper pilot technique, but I often see pilots in backcountry settings doing pre flight run ups which make me cringe.

Magnetos are amazingly durable, all things considered.

MTV

That’s not been my experience

Engine attached stuff wise, mags crapping out are up right there with dry vacs

If remote, you have the engine run ruff, or your engine instruments looked off, or the engine just didn’t feel like it normally does, would you not do a run up? and if one of your two mags was bad would you still fly?

Ummm, is that intended to be insulting, or???

If I ever had a rough running engine ANYWHERE, I figured out what the problem was before I launched. A brand new Cessna 185 fouled injectors frequently, and that thing shook like hell when that happened, and it happened frequently for over the first 200 hours. I got good at landing on a lake, pulling the top cowl, finding the offending injector and cleaning it.

I’ve cleaned a LOT of spark plugs due to rough running engines.

I’ve never had a magneto failure, either in a work or personal airplane, but writing that will likely jinx me now.

There’s this thing called “maintenance” , which, when carefully and regularly completed will prevent MOST magneto problems.

Or, maybe I’m just lucky…..

MTV

No insult

And maintenance, I have seen 2yr old planes pampered with mx, under warranty and also owners who don’t have a issue spending money “just make it right” have mags take a dump


Im highly, like super highly surprised for the level of hours you apparently have that you never had a mag take a dump, it’s possible, but man that’s some near lotto odds if you have over 2,000hrs or so in pistons

Only high time guys I know who haven’t enjoyed a shit mag have been people who ended up and stayed in the turbines early on and don’t GA much

I think my flight from the beach town I stopped at, to the mechanic shop was made with just one mag.
It was only 20NM , over some water, if I did a mag check and found the faulty mag , I would have climbed to high altitude to do this flight, instead of doing a sightseeing flight at 1500ft.

motoadve wrote:I think my flight from the beach town I stopped at, to the mechanic shop was made with just one mag.
It was only 20NM , over some water, if I did a mag check and found the faulty mag , I would have climbed to high altitude to do this flight, instead of doing a sightseeing flight at 1500ft.

I’m all for calculated risk, but damn

If you got a mag out out, you should have known it

And if flying with an dead mag on that engine, that’s no bueno

So if the mill shits out shortly after rotation?

You got one small engine…and it’s sick..

At work I also fly a decently powered twin jet, put you in the back of your seat on t/o powerful, if just one of the two engine was having issues I’d stand down

To each their own

Personally Id have paid to have the AP drive out if it was that close, or rent a car and pick him up, and swap it on the ramp it were me, heck I’d buy the dude lunch after too

To me it’s one thing to jump a crap battery in a VFR ship with mags, or fly with a nav light out or something, but these ain’t old school diesels, or turbines, if the plugs ain’t sparking you ain’t going to be flying for long

NineThreeKilo wrote:

mtv wrote:

NineThreeKilo wrote:

mtv wrote:It depends, but generally, I do one mag check per flying day. Redundancy of essential systems is why these things have two totally independent ignition systems.

Some days at work, I’d have five, six or more stops. Lots of those in places where getting a mag and mechanic delivered would be tough.

The bigger issue I see with mag checks is prop damage, which can be mitigated by proper pilot technique, but I often see pilots in backcountry settings doing pre flight run ups which make me cringe.

Magnetos are amazingly durable, all things considered.

MTV

That’s not been my experience

Engine attached stuff wise, mags crapping out are up right there with dry vacs

If remote, you have the engine run ruff, or your engine instruments looked off, or the engine just didn’t feel like it normally does, would you not do a run up? and if one of your two mags was bad would you still fly?

Ummm, is that intended to be insulting, or???

If I ever had a rough running engine ANYWHERE, I figured out what the problem was before I launched. A brand new Cessna 185 fouled injectors frequently, and that thing shook like hell when that happened, and it happened frequently for over the first 200 hours. I got good at landing on a lake, pulling the top cowl, finding the offending injector and cleaning it.

I’ve cleaned a LOT of spark plugs due to rough running engines.

I’ve never had a magneto failure, either in a work or personal airplane, but writing that will likely jinx me now.

There’s this thing called “maintenance” , which, when carefully and regularly completed will prevent MOST magneto problems.

Or, maybe I’m just lucky…..

MTV

No insult

And maintenance, I have seen 2yr old planes pampered with mx, under warranty and also owners who don’t have a issue spending money “just make it right” have mags take a dump


Im highly, like super highly surprised for the level of hours you apparently have that you never had a mag take a dump, it’s possible, but man that’s some near lotto odds if you have over 2,000hrs or so in pistons

Only high time guys I know who haven’t enjoyed a shit mag have been people who ended up and stayed in the turbines early on and don’t GA much

I guess you just hang out with unlucky folks…..

Just hanging out in the real world of working pilots and not “content creators”


I’m still a little star struck, you come off as you have like 10,000+hrs in radials and other pistons, you have NEVER had a mag failure??

NineThreeKilo wrote:

motoadve wrote:I think my flight from the beach town I stopped at, to the mechanic shop was made with just one mag.
It was only 20NM , over some water, if I did a mag check and found the faulty mag , I would have climbed to high altitude to do this flight, instead of doing a sightseeing flight at 1500ft.

If you got a mag out out, you should have known it

Exactly. If you have an engine analyzer, and especially if you cruise in "normalized" EGT mode, diagnosing any ignition problem whether it be one plug or an entire magneto is easily identified. And if you do an in-flight mag check with a faulty mag, your engine will quit when you shut off the good mag. The restart procedure for a dead mag and a dead engine is not as simple as turning your other mag back on either unless you are so fast that you don't run into a problem. Read the article by Deakin. Mixture lean. Then mags back on before bringing the mixture back in.

NineThreeKilo wrote:Just hanging out in the real world of working pilots and not “content creators”


I’m still a little star struck, you come off as you have like 10,000+hrs in radials and other pistons, you have NEVER had a mag failure??

“Content creator”.

I love it! Believe what you like.

Sorry I’m not living up to your vision for me.

MTV

motoadve wrote:I think my flight from the beach town I stopped at, to the mechanic shop was made with just one mag.
It was only 20NM , over some water, if I did a mag check and found the faulty mag , I would have climbed to high altitude to do this flight, instead of doing a sightseeing flight at 1500ft.

If you were flying on one Mag you would have had elevated EGTs on all 6 cyldiners by at least 50F along wtih hotter CHTs. Did you notice anything unusual on the engine monitor during that flight ? Would have been even more noticeable on the climb out. It could have crapped out on the ground after you landed too. Another reason to check both L/R magneto function before takeout - is just to ensure they are set to both. I know you can visually check it but it always nice to see a rise and fall in RPM/EGT.

Is there are downside to checking the mags after each engine start ?


Josh

The restart procedure for a dead mag and a dead engine is not as simple as turning your other mag back on either unless you are so fast that you don't run into a problem. Read the article by Deakin. Mixture lean. Then mags back on before bringing the mixture back in.

I was riding in a 68 Chevy Impala with a cousin that was acting crazy. We turned the key off on her and you should have heard the bang when it was turned back on. I don't think we blew the muffler though.