Maintaining your magnetos
Magneto inspection periods
When should I have my mags inspected ?
This is one of the most frequent questions we hear from G.A owner/operators, usually in a tone of concern as the enquirer is often expecting a prohibitive quote with the answer.
Fortunately OEM service manuals take the guess work out of the equasion.
Most general aviation magnetos on a typical Lycoming or Continental piston engine either use Slick or Bendix magnetos.
The magneto manufacturer (O.E.M) specifies periodic inspection intervals and maintenance procedures which are defined in the Manufacturer's Master Service Manual.
Your aircraft P.O.H. also details how to perform a "mag drop" check when you do your pre-flight run-up.
If you get a mag drop you need to get your mechanic to find out the cause. If it leads to a faulty mag that would be a good time to get your mags inspected by an approved repair station.
An annual inspection by your A&P or AME/AMO every 100 hrs operational time or 12 months calendar time will usually identify if your magnetos need inspection.
Your mechanic or the aircraft owner should be keeping a record of the date of installation, hours on the mag at installation and how much time you have got left until your next 500 hr inspection.
The 500 hr inspection will involve the following:
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Mag removed and inspected
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A.D.s and S.B.s checked for compliance
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Mag opened & cleaned.
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External/internal corrosion dressed.
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Individual components, bearings, seals and gaskets inspected/replaced.
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Impulse coupling inspected.
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All springs & some hardware replaced.
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Coil, capacitor, contact breaker and distributor block assembly inspected & replaced where neccessary.
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Replace any worn parts, seals, lock washers, gaskets and damaged hardware.
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Mag reassembled, bench tested, quality control approved.
This inspection should be done by a specialist.
We will buy your used magneto cores if they are
re- usable.
Runout magnetos that are recently removed and within current specifications are sought.
We will buy them from you subject to an acceptance inspection so please download a core credit form below. Fax or e mail the form to us and we will arrange shipping.
When should my mags be overhauled?
Manufacturers of both Bendix and Slick magnetos have published recommended service times when your magneto should be overhauled.
Magnetos must be overhauled when your engine is overhauled and should not have a greater in- service time than the T.B.O hour limit for the engine on which they are installed.
Magnetos must be overhauled after a lightning strike on the aircraft, a sudden stoppage, prop strike, overspeed or immersion.
TCM Continental also specify a 4 year calendar time overhaul for Bendix magnetos irrespective of operational time.
The overhaul procedure will involve
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the removal of the mag from your engine
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mag opened ,cleaned, inspected, N.D.T where required
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some major components, bearings, seals and gaskets replaced
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impulse coupling inspected or replaced
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springs replaced, coil, capacitor, contact breaker assembly and distributor block assembly inspected or replaced
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all worn parts, seals, lock washers, gaskets and damaged hardware replaced
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Mag bench tested and quality approved.
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All A.D.s & S.B.s complied with.
Magneto Exchange Service
The Magworx hangar and modern magneto component shop is open for business at Pitt Meadows Airport (CYPK)
We are set up to turn around a set of mags for 500 hr inspection within 3 working days for typical basic training aircraft.
We can get them out in 1 day in case of real emergency but also hold re-manufactured mags on the shelf for loan whilst yours is being repaired.
Another fast turnaround option is our offer of a re-manufactured exchange magneto service.
You can get ignition-related parts or spares from our Magshop.
Inventory includes ignition harnesses, spark plugs, magneto drive gears, gaskets, grommets, mounting hardware, batteries and the list is growing daily.