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Mags: IRAN Or Exchange?


AlexLev

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On 7/9/2020 at 7:57 PM, GeeBee said:

Think about it. How long until the cast housing stretches? You can put all the new "guts" in, but when you are finished, you still have a cast housing that is taking a beating, from the bearing races to the seal seats, to the threads the screws turn into, not to mention the flanges which are bolted down with steel billets. Also for whatever reason, many places check the coils but do not replace the coils. Seen a lot of recently O/H mags come up with a bad coil, because they test good on the bench until you heat stress them then it all goes bad. After 1000 hours, I want a new coils and a new coils are about 400 bucks. Add in the rest of the parts and labor and you might as well buy new. Plus when it goes bad, there is no head scratching and "I'll send it back for a rework", you get a new magneto. IMHO, in a SE airplane, the gods of high tension electricity must all  be simultaneously appeased for their wrath of each is mighty. 

My Bendix have 32XXTT (many IRANs) and we’ve seen no evidence of housing “stretch”. Indeed this is the first I’ve heard of it. AFAIK we’ve had one in flight failure (coil shorted to case), other than that they have been unremarkable, which is to say almost no effect on dispatch reliability.

Edited by Shadrach
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Here’s the inside of one of the new electric ignition system posted by a Comanche owner. I don’t remember the exact details, but it was a new unit with 100+/- hours when it shed the teeth from the gear.

Clarence

E652EB69-9CFE-4113-8606-7BA38B3A5450.jpeg

Edited by M20Doc
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9 hours ago, Shadrach said:

My Bendix have 32XXTT (many IRANs) and we’ve seen no evidence of housing “stretch”. Indeed this is the first I’ve heard of it. AFAIK we’ve had one in flight failure (coil shorted to case), other than that they have been unremarkable, which is to say almost no effect on dispatch reliability.

Ahhhh, the coil.....

 

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1 hour ago, M20Doc said:

Here’s the inside of one of the new electric ignition system posted by a Comanche owner. I don’t remember the exact details, but it was a new unit with 100+/- hours when it shed the teeth from the gear.

Clarence

E652EB69-9CFE-4113-8606-7BA38B3A5450.jpeg

As far as that unit goes, I am not a buyer. I have seen too many problems with it.

 

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Does anyone have any experience with the brand new Kelly dual mag? 

from their website...

In 2018, KAES introduced the completely new manufacture D2000/D3000 magnetos featuring 100% new parts.   Kelly takes pride in that we support 25,000 owners of engines with the Dual magneto and we provide a magneto with numerous key improvements over the original D2000/D3000 magnetos.

  • All aluminum frame to replace troublesome magnesium frames. The aluminum frame is stronger, longer lasting and far less likely to crack or corrode like the original magnesium frames.
  • All new distributor block and gears. Thousands of these parts have been installed with tens of thousands of flight hours accrued over the past 20 years.
  • All new coils, condensers and contact points.
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11 hours ago, MikeOH said:

Not even sure you could pull accident data like this, but I'd be curious to know how many in-flight engine stoppages have been due to failed points?  Probably pretty low as one mag would really already have to be out.

Not really the point. How many taxi backs to the hangar for a bad mag check? A lot.

 

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11 minutes ago, PTK said:

Does anyone have any experience with the brand new Kelly dual mag? 

+1

I’d love a pirep on these too. I’m due for a 500-hour this year, and I’d be very tempted to go with a new unit if they’re better. 

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57 minutes ago, toto said:

+1

I’d love a pirep on these too. I’m due for a 500-hour this year, and I’d be very tempted to go with a new unit if they’re better. 

They went with aluminum rather than magnesium for cost savings no doubt. But Mg is superior to Al  for casting to tighter precision and tolerances. I don’t know what they mean by “...troublesome magnesium frames...” I’m not versed on mag construction. Are magnesium constructed mags troublesome?  It was my impression magnesium is superior to aluminum for these things. It is also about 1/3 lighter. Does it even matter what the frame material is?

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1 hour ago, GeeBee said:

Not really the point. How many taxi backs to the hangar for a bad mag check? A lot.

 

Do you have data to support that?  Or are you just throwing out some bull$h!t to support a weak (nonexistent) point?

In 31 years of flying piston airplanes, the only times I've ever taxied back for a bad mag check had nothing to do with the magneto, but with a fouled spark plug.

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26 minutes ago, Andy95W said:

Do you have data to support that?  Or are you just throwing out some bull$h!t to support a weak (nonexistent) point?

In 31 years of flying piston airplanes, the only times I've ever taxied back for a bad mag check had nothing to do with the magneto, but with a fouled spark plug.

I have to agree.  In more than 35 years as a maintainer, outright failure of a magneto is surprisingly rare.

Clarence

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29 minutes ago, Andy95W said:

the only times I've ever taxied back for a bad mag check had nothing to do with the magneto, but with a fouled spark plug.

+1

A failed mag check for me has only ever been caused by a fouled plug. 

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I had a bad condenser that manifest only when heated.  It still sparked but just weak.  Weak enough that it manifest as an inability to start until the accessories came back to ambient temperature.  Found out after mx I stopped for gas and had to spend the night in a pilot lounge.   .  

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6 hours ago, M20Doc said:

I have to agree.  In more than 35 years as a maintainer, outright failure of a magneto is surprisingly rare.

Clarence

Yup. Never scrubbed a trip for a bad mag. Bad plugs? Yes. Shorted harness? Yes. Bad Voltage Regulator? Sure...My anecdotal experience is that the Bendix 200 series mags on our plane are probably the most reliable system on the aircraft. 

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6 hours ago, GeeBee said:

Probably about 6 or seven in 8k hours. I used to fly checks at night, lots of bad leads rotors etc. which is caused by guess what? Bad mag. That is just me. Now think about 25 airplane fleet every night.

 

Hmm, what I think about is that you were flying for a company that wasn't big into maintenance:o That's nearly one failure per 1000 hours. YIKES. And, I really wouldn't count bad leads as a mag failure. Poor maintenance, yeah.

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10 hours ago, Andy95W said:

Do you have data to support that?  Or are you just throwing out some bull$h!t to support a weak (nonexistent) point?

In 31 years of flying piston airplanes, the only times I've ever taxied back for a bad mag check had nothing to do with the magneto, but with a fouled spark plug.

In your hostility, you missed the point, or points (pun intended). You are not going to see an engine quit due to a mag failure, because......ta da! There are two of them. You are more likely to see a return to base in the case of a mag failure, than an engine failure because most pilots are unwilling to risk flight on one system.  

Glad to see you have 31 years, but I have 20 more than that, 47 in fleet operations, so let us not get too caught up in mine's bigger and seek a larger truth. Mags suck.  They have lots of failure points that require attention and put out a weak spark in comparison to modern systems.

 

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20 minutes ago, MikeOH said:

Hmm, what I think about is that you were flying for a company that wasn't big into maintenance:o That's nearly one failure per 1000 hours. YIKES. And, I really wouldn't count bad leads as a mag failure. Poor maintenance, yeah.

As an FAA friend once said to me. "IF I wanted to retire, I would go to the. small plane air cargo ramp at LAX or MIA and just start in. I could generate enough violations to last a career." I flew for several companies in that time period, and the operation of Part 23 aircraft in daily scheduled operations is a perilous one. The airplanes are not designed for that kind of use and it shows quickly. In the 70's flying jobs were not easy to come by (lots of VietNam vets), multi time was a god send, and a dismissal from a crap operator would be the end of airline dreams. Things were not always as fat as they are now. Back then, you were expected to complete the mission, or they would get someone else very quickly. I worked for on operator who would fire a pilot who shut down engines and could not restart, even if it was a starter failure. You were expected to leave them running, during loading and unloading.

 

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1 hour ago, GeeBee said:

In your hostility, you missed the point, or points (pun intended). You are not going to see an engine quit due to a mag failure, because......ta da! There are two of them. You are more likely to see a return to base in the case of a mag failure, than an engine failure because most pilots are unwilling to risk flight on one system.  

Glad to see you have 31 years, but I have 20 more than that, 47 in fleet operations, so let us not get too caught up in mine's bigger and seek a larger truth. Mags suck.  They have lots of failure points that require attention and put out a weak spark in comparison to modern systems.

 

In my search for flying hours, I've also had to fly some crap airplanes.  Not as many or as bad as you've done, but I get it.

Since you've been posting on MooneySpace, you've contributed a lot of good information and a number of solid opinions.  But your opinions about magnetos are based upon your own very unique experiences.  Those are very different from the experiences of people here who have flown airplanes with magnetos that received basic proper maintenance.

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16 hours ago, M20Doc said:

Here’s the inside of one of the new electric ignition system posted by a Comanche owner. I don’t remember the exact details, but it was a new unit with 100+/- hours when it shed the teeth from the gear.

Clarence

E652EB69-9CFE-4113-8606-7BA38B3A5450.jpeg

So far the tales of trouble with the electronic systems seem to be outnumbering the success stories in my observation.    I think they're not quite ready for prime time yet.   It might take another generation or two to get it right, but the factory FADEC/electronic systems may get their first, like the Lycoming iE stuff, or the smaller manufacturers like UL.

 

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12 hours ago, EricJ said:

So far the tales of trouble with the electronic systems seem to be outnumbering the success stories in my observation.    I think they're not quite ready for prime time yet.   It might take another generation or two to get it right, but the factory FADEC/electronic systems may get their first, like the Lycoming iE stuff, or the smaller manufacturers like UL.

 

I think lyc is piggybacking on Surefly though... don’t they offer an electronic mag with some of their engines that’s simply a rebranded SF?

I like my SF so far, but time will tell...

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Most the problems I am seeing with electronic are mechanical, not electrical.

The largest producer of aircraft gasoline powered engines right now is Rotax. Are they using magnetos? Hear of a lot of ignition problems with Rotax? 

You can continue to defend magneto ignition, invented in the 19th century to run our airplanes in the 21st century. We should demand better because we should be getting better 20 years into the 21st century. So many good things would come out of a hotter and longer spark for the efficiency and longevity of our engines. If I were a cylinder or valve manufacturer, I would be cheering on fixed timing, magneto ignitions.

 

 

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Mags have served their purpose for very very long time. The motorcycle industry started migrating away from them in the late 70’s, some of the very early CDI ignitions (capacitor discharge ignition) had early failure rates due to heat but it was quickly resolved. Now they are mostly all digital ignitions and fuel injected which allows some serious timing to be cranked in resulting in more power. Hell, you can change the fuel MAP on dirt bikes with an app on your phone via Bluetooth. Top Fuel dragsters use some serious electronic mags with rare earth magnets that are hell for stout, I’ve heard that the horsepower needed to drive the 2 mags, 2 fuel pumps and the blower on a Top Fueler is more than a NASCAR engine can produce. If you have never seen a Top Fuel Dragster run in person you owe it to yourself at least once, 12+ gallons in less than four seconds, not as efficient as our Mooneys but the seating position is very close :D

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1 hour ago, GeeBee said:

Most the problems I am seeing with electronic are mechanical, not electrical.

The largest producer of aircraft gasoline powered engines right now is Rotax. Are they using magnetos? Hear of a lot of ignition problems with Rotax? 

You can continue to defend magneto ignition, invented in the 19th century to run our airplanes in the 21st century. We should demand better because we should be getting better 20 years into the 21st century. So many good things would come out of a hotter and longer spark for the efficiency and longevity of our engines. If I were a cylinder or valve manufacturer, I would be cheering on fixed timing, magneto ignitions.

 

 

Well, other than you, I don't hear of a lot of ignition problems with those ancient tractor mags you so despise, so I'm not sure what your point about Rotax proves??  Frankly, I've heard about more issues with a VERY small data set of E-mag users.  Back to the original start of this debate: I don't think the FAA is anywhere near "crazy" denying dual E-mag installations. Pretty prudent and smart, IMHO.

I'm still waiting for a cogent argument about what benefits variable timing brings to a stationary engine.

IIRC, you change out mags after a couple of overhauls due to your fear of a deteriorating coil.  You do realize that E-mags still have a coil, right?  The only thing all that added electronics bring to the party is to replace a SINGLE component: the points.  My understanding is that these are NOT multiple coil systems so you still have a rotor and high-voltage spark plug wires.

Yes, it allows variable timing....as I've stated, I'm just not seeing the big advantage . I'll concede that you get easier starts.  So, those that install ONE E-mag I get it.

Oh, on the 'hotter spark' thing.  There is no reason a conventional points system cannot be designed with a larger coil for more energy; that is not a 'feature' that requires an E-mag.  Also, keep in mind that while you could design a system that would clear just about any fouled plug, should you?  If you have chronic fouling, something else is wrong.  Personally, I wouldn't want that hidden by a 'hotter, longer spark.'. I suspect that the original engineers that designed aircraft mags understood all of this and optimized size/weight/spark energy to fit the application.  In other words, they were good engineers, not professors desperate to apply new technology to every application they could find.

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