Mag STC for Cessna R/TR182

Norman

Norman

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Anyone know of an STC or even a filed 337 to change the mags from the D2000 or D3000 to separate mags? Engine is an O540L3C5D or O540J3C5D. I have a friend who would like to make that change if he can find paperwork for approval.
 
Awesome I will prolly do that when ours dies. Previously only was I saw was through an Stc for a 260 or 300hp injected engine.
 
Doesn't this constitute a major alteration ? Doesn't it require you to replace the accessory case ? thus the designation of the engine?
 
Tom-D said:
Doesn't this constitute a major alteration ? Doesn't it require you to replace the accessory case ? thus the designation of the engine?
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It drops the "D" off the end of the engine model. I imagine you'd have to check the type certificate to see if the separate magneto engine model is approved to be used, unless you're going to do a field approval or an STC to put it on.

I have been under the impression that both the engine case and the accessory case are different, and probably all the accessory gears are different as well. In other words, it would basically require a different engine.
 
mondtster said:
It drops the "D" off the end of the engine model. I imagine you'd have to check the type certificate to see if the separate magneto engine model is approved to be used, unless you're going to do a field approval or an STC to put it on.

I have been under the impression that both the engine case and the accessory case are different, and probably all the accessory gears are different as well. In other words, it would basically require a different engine.
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Its my understanding that there are some engines that can be converted without replacing the crankcase, but still many other parts.
 
bnt83 said:
Its my understanding that there are some engines that can be converted without replacing the crankcase, but still many other parts.
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Crankcase?? or did you intend it to say Accessory case?
In either case this will change the designation of the engine.
To follow, if the designation of the engine is changed can it be used on that aircraft ?
 
Tom-D said:
Crankcase?? or did you intend it to say Accessory case?
In either case this will change the designation of the engine.
To follow, if the designation of the engine is changed can it be used on that aircraft ?
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Right. I think some the entire crankcase has to go, others not. Probably all accessory cases have to go. Example, is the O-320-H2AD crankcase common with any other engine? I don't think so.

I really feel lycoming should be selling a kit with a new dataplate for eligible engines.

Cessna should write a service letter telling owners which engines can replace the duel mag ones, and then revise TCDS to include them.
 
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Norman said:
Anyone know of an STC or even a filed 337 to change the mags from the D2000 or D3000 to separate mags? Engine is an O540L3C5D or O540J3C5D. I have a friend who would like to make that change if he can find paperwork for approval.
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I can't find any STC that will get this done.
 
If you have a "D" engine Lycoming (with the dual mag) you can't simply change out to two independent mags. The accessory housing and the crankcase are physically different. You would need an STC for a different engine type that would have two independent mags.

Personally, I would go with the Electroair ignition option. That gives you electronic ignition (a benefit) and then gives you two independent mag sources.

For what it's worth, I've never liked the dual mag. I've seen lots of problems with them. There should be two independent sources of ignition on our engines.
 
Yup. Afraid to say you're stuck with the Siamese mag. Swapping accessory cases changes the designation of the engine, and most TCDS unfortunately tie you to just the D suffix engine. On those where the airplane came in both variants, swapping the engine out can be accomplished, but it's equally uneconomical unless the sucker is run out. Other than some late run Saratoga's, and the m20J, I haven't seen a Siamese engine airplane model that offered the non-D variant as part of the standing TCDS.

The reason you can't find paper STC that allow engine swaps for this purpose is as stated above, it's extremely uneconomical to swap entire cores just to gain a new accessory case, which is why the market never clamored for it. BUT, now that the Siamese mags are orphaned, there will come a time where the market will be forced to come up with an allowance to all these airplanes waiting to get grounded for lack of parts. It wouldnt surprise me if they managed to paper fix it to where you could swap engines for non D variants at overhaul.

One of my driving criteria for selecting the arrow over better book performers such as the m20j or 177rg was my aversion to the shared drive dual mag. Time and time again it has been shown that it's not the case gearing that fails, it's the flimsy and heated components on the mag side that do, plus the all too common clamp slide out post MX. Sharing the housing, the drive AND the retaining clamps is just dumb. Don't kid yourself, you're flying on one mag with the Siamese. The only way I fly behind a Siamese mag, is if I have two Siamese mag engines LOL.
 
Dual mags can still be overhauled. no emergency forcing the issue.
 
Tom-D said:
Dual mags can still be overhauled. no emergency forcing the issue.
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Yes they can... For now... My aero club just had one overhauled a month ago, very few people want to work on them. This overhaul was $2k (Plus a $1k core charge). Then 10 hours later, it was sent back to the repair station to do it again. The internal shaft had actually twisted (3rd part info here) and it would no longer time correctly.

Luckily, they covered it under warranty the second time... Probably next year, the whole engine (Lyc O-320-H2AD) will be off at TBO, and getting replaced with a 180hp conversion.
 
thomasdr72 said:
Yes they can... For now... My aero club just had one overhauled a month ago, very few people want to work on them. This overhaul was $2k (Plus a $1k core charge). Then 10 hours later, it was sent back to the repair station to do it again. The internal shaft had actually twisted (3rd part info here) and it would no longer time correctly.

Luckily, they covered it under warranty the second time... Probably next year, the whole engine (Lyc O-320-H2AD) will be off at TBO, and getting replaced with a 180hp conversion.
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Won't it be nice when the FAA allows dual electronic ignition and fuel injection retro fits to certified engines..
we are hoping for hell to freeze over too.

It's not like it isn't a impossibility
http://sdsefi.com
 
thomasdr72 said:
Yes they can... For now... My aero club just had one overhauled a month ago, very few people want to work on them. This overhaul was $2k (Plus a $1k core charge). Then 10 hours later, it was sent back to the repair station to do it again. The internal shaft had actually twisted (3rd part info here) and it would no longer time correctly.
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If you're a mechanic, why didn't you just open it up and fix it? I'd bet the shaft itself didn't "twist". More likely would be that the cam to open and close the points slipped, as it is a tapered press fit (no keyway).

I really don't understand all the hatred for these magnetos or why someone would avoid working on one. It's just another magneto, the principles are the same as the separate ones and the manuals are readily available to work on them.
 
mondtster said:
I really don't understand all the hatred for these magnetos or why someone would avoid working on one. It's just another magneto, the principles are the same as the separate ones and the manuals are readily available to work on them.
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The impulse spring is the weak link. If it corrodes (and they do) it can break, sending both mags to full retard, where the power loss is almost complete.
 
Dan Thomas said:
The impulse spring is the weak link. If it corrodes (and they do) it can break, sending both mags to full retard, where the power loss is almost complete.
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I was meaning from a mechanic's standpoint, working on them. But yes, a broken impulse and all spark being retarded would indeed be a problem.
 
Tom-D said:
Won't it be nice when the FAA allows dual electronic ignition and fuel injection retro fits to certified engines..
we are hoping for hell to freeze over too.

It's not like it isn't a impossibility
http://sdsefi.com
Click to expand...

That's what the Lycoming iE2 is. It would be allowed today if you went through the certification effort.

The main issue is that once you use airframe power to power the ignition and fuel system, now you need some sort of backup that will allow you to keep flying in case of a failure. There are different ways one can go about this.

I would make it all electronic if I could, but I'd also significantly increase the complexity of the electrical system to provide appropriate redundancy.
 
air boss from AERO is the best place to get that mag
 
mondtster said:
If you're a mechanic, why didn't you just open it up and fix it? I'd bet the shaft itself didn't "twist". More likely would be that the cam to open and close the points slipped, as it is a tapered press fit (no keyway).

I really don't understand all the hatred for these magnetos or why someone would avoid working on one. It's just another magneto, the principles are the same as the separate ones and the manuals are readily available to work on them.
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It was another shop's baby to deal with, something I didn't have time to do... I'm only a consultant to operations there, as I don't have enough time be a paid employee ;-)
 
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