My Mags are getting close to a 500 Hr inspection. any recommendations where to go? Also, is it best to go for an overhall or an ‘IRAN’ and what is the typical cost of either.
It would depend on which type of magneto’s. For example Slick magneto’s are usually inspected, while Bendix magneto’s get inspected or overhauld. Some manufacturers copy the Bendix recommend 4 year interval for overhaul.
IMHO it doesn’t make sense to ship magneto’s all the way to the USA. There are quality shops in Europe as well. I sometimes help out Vliegwerk Holland. There component guy is doing magneto’s, starters and alternators only for over 30 years.
They charge about $700 for the D3000 dual mag.
This is not possible for an overhaul when using orginal parts. Either you recall the price incorrect or something gets skipped.
When shipping these kinds of parts, have them packed very carefull and use a quality courier. I have seen parts coming in damaged due to poor packing.
After watching a Mike Busch Webinar about slick magnetos (which have plastic cogs), I am now much more worried about my ignition system………….sometimes I think it’s better to live in blissful ignorance as I had imagined dual mags would not both fail in a way that they could massively screw up the timing.
A very useful tip with Slick Mags ……….if your engine massively starts misfiring………. turn off one mag, then the other as the teeth on the cogs may have sheared off and one mag could be massively mistimed. Out of a few instances of that happening in the U.S, not one pilot did tried this and they ended up with forced landings/ trashed the planes…………….I am absolutely sure I wouldn’t have tried that either as (a) I wasn’t taught that and (b) I’m 99% sure that scenario is not mentioned in the “Aircraft Technical” exam.
I fly over water quite a bit and the thought of old crumbly plastic cogs doesn’t fill me with confidence………….especially if it’s like the plastic trim parts in my 39 year old cabin! I’ve got about 200 hours before my IRAN but I think I might do my mags early as at least I’ll know it’s been done properly……….I’ve only owned the plane for 250 hours.
USD 1,000 will look very cheap when you’ve conked out & are gliding half way over the channel at 50 degrees North!
Thanks for the links for the IRAN shops in Europe guys -
A Fantastic Forum, it’s helping me lots!
After watching a Mike Busch Webinar about slick magnetos (which have plastic cogs)
All magneto’s have some form of plastic gears. Broken tooths on the gears are extremely rare on fixed wing aircraft. On helicopters they are far more common on Bendix magneto’s. Therefor some operators send them in for regular gear change, which will prevent this kind of situation.
Currently an issue on slick magneto’s (which I personally favor over Bendix / TCM) is that the distrubution gear finger is loos (firing to a random cylinder). It seems these manufacturers are always try to save a few pennies. As this didn’t happen before. Bendix/TCM is IMHO less robust, far more sensitive for issues trough vibration, or sometimes even stupid design, such as on a dual magneto, where both cams are installed with one screw, on a axle with keyway. On Slick magneto’s, you can not adjust the cam. Of the Bendix/TCM IMHO the 1200 series magneto’s are best, they are large, VERY powerfull and less vibration depended then the smaller family.
What I always find amazing, is that quit a lot of people and companies ignore manaintence on such an important system. Although it is quite common in some countries to have a mechanic performing these inspection, they will be unable to find all possible faults before something goes wrong. One needs specialised tools, and a test bed to do a proper job.
A while a go a magneto was send in for analysis as it was running rought, this was a slick magneto, where an allen key/wrench was found inside the distributor. Likely this was used as incorrect tooling for timing, forgotten about, and turned right into the distributor housing.
AFAIK the reason for plastic gears is to ensure that if something “downstream” of the said gear fails, the gear will shear off, protecting the (metal) gears in the accessory gearbox which all kinds of essential other stuff like the other mag, the camshaft, etc allowing the other mag to drive the engine.
This idea is considerably compromised in the D3000 single shaft dual mags, of course…
The vac pump also has a plastic coupling, for the same reason. You don’t want to bugger the engine if the vac pump jams.
What I always find amazing, is that quit a lot of people and companies ignore maintenance on such an important system. Although it is quite common in some countries to have a mechanic performing these inspection, they will be unable to find all possible faults before something goes wrong. One needs specialised tools, and a test bed to do a proper job.
Example: Recently I saw a EASA certified maintenance shop replacing breaker points in a Slick.
When I asked if they had the e-gap tool I got a blank stare and then they explained that just setting the point gaps did the job.
You need to check both the Efficiency Gap AND the points gap to get these mags set-up properly .
I can’t see why you would want to want to send two slick Mags to the USA for the 500 hour check when you can send them to NMA in Wokingham?
Thanks for the replies to my very old thread!
I’ve owned my PA 28 for 3 years or so and I have got 306 hours on my Slick Mags
The mags were checked as part of the purchase deal along with a new prop and some other items which needed sorting. I have absolutely no reason to doubt the competency of the maintenance organisation that did the work …….in fact I did one owner assisted Annual with them and they were very, very good.
Over the last 3 years I have done numerous oil changes every 25 hours with no metal, I have boroscoped the engine every 6 months and I am familiar with most parts of my plane having done 3 owner assisted Annuals.
However “Mags IRAN” are the one of the few item I have never personally been involved in and that worries me over long water crossings. I am tempted to have at least one mag comprehensively overhauled in the next 12 months and have this fitted and timed by my present engineers.
Based on the experiences of a friend, there is no way I would send this to NMA as mentioned above. I’m tempted to use Peter’s firm in the US but any other recommendations?
I’d like to get a rebuilt mag and then send mine as an exchange but perhaps I should get one from a “chop shop” and have a rebuilt one permanently on the shelf. I like the idea of staggered replacements so that both are not replaced at one Annual – it seems safer.
As I said, any comments or recommendations?
I am about to send my spare mag to QAA again. I am merely waiting to combine it with something else so as to make the DHL shipping cost a bit less extortionate