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We found significant metal debris on the magnetic plug of our 915 Eurofox at the first 25-hour oil change, as did a sister gliding club with an engine 1 serial number different. Our experiences since then have been almost identical.

CFS, the UK Rotax agents requested that we remove the gearbox and send it for inspection as the most likely source of the metal. They stripped the gearbox and there were signs of the overload-clutch slipping, but it was confirmed that the debris did not come from the gearbox. This means that 2 engines each had the same 2 distinct problems – a slipping overload clutch and metal debris from an unknown source, which suggests a serious quality issue in Rotax’s manufacturing, assembly or QA processes.

The gearbox was returned with a new overload clutch and we were requested to do a 30-minute ground run and re-check the magnetic plug. If it was clear, then the aircraft was to be flown for a further 25 hours and another oil + filter change performed. In both cases, there was more metal debris after the 30-minute ground run, with one more than the other.

Has anyone else experienced this problem as it’s hard to imagine only 2 engines would be affected ? Also, the BUDS logs did not show any overspeed events, so the clutch must have been slipping, but not excessively. This may be a widespread problem that no-one knows about yet, but what are the long term implications ?

Disappointingly, CFS supposedly obtained approval in writing from Rotax to replace our engine and bizarrely withdrew this option, insisting we flew it for a further 25 hours – so much for “no-compromise warranty” !

11082_1_Eurofox 1 - 25hr oil change 1.jpeg (You do not have access to download this file.)
11082_1_Eurofox 1 - 25hr oil change 2.jpeg (You do not have access to download this file.)
11082_1_Eurofox 1 - 25hr oil change 3.jpeg (You do not have access to download this file.)
11082_1_Eurofox 1 - 25hr oil change 4.jpeg (You do not have access to download this file.)
11082_1_Eurofox 1 - 25hr oil change 5.jpeg (You do not have access to download this file.)
11082_1_Eurofox 2 post 30min ground run 1.jpg (You do not have access to download this file.)
11082_1_Eurofox 2 post 30min ground run 2.jpg (You do not have access to download this file.)
  • Re: Metal debris after 25 hours – 2 Engines

    by » one week ago


    Yikes. Most of that looks to me like machining swarf, but how would that much ferrous swarf get into an aluminum engine case?

    I don't think I would fly that engine beyond gliding distance from the departure runway until it's determined to be undamaged or is replaced.  Is CFS offering to pay for the fuel so you can circle the airport for 25 hours, or do they prefer that you to risk your aircraft and your health at your own expense?  I'm guessing the latter.


  • Re: Metal debris after 25 hours – 2 Engines

    by » one week ago


    I totally agree Eric - and of course it's the latter !


  • Re: Metal debris after 25 hours – 2 Engines

    by » one week ago


    Hi All

    I am familiar with the new gearboxes used on the type 915 and 916.  The material I believe is from that part of the engine.  The clutch packs are assembled by many pieces and there are circlips, clutches (2) and the overload clutch system as well.  One look at this and the amount of parts it is easy to imagine some swarf from all those parts.

    The good bit here is that the magnetic chip detector is as the oil is drawn back into the crankcase (not into the oil pressure side) and it is then returned via crankcase blowby gases to the oil tank.  Any materials would have to pass the tank, the oil cooler, the oil pump and the oil filter to get into any critical engine parts like lifters or crank and cam bearings.  I believe you are pretty safe in that respect.  The overspeed i doubt would create the pieces, it is likely left over from assembly.  The 25 hour inspection is to find exactly this type of think before you do long oil changes.  

    Not sure that will make you feel any better but if they could not find anything with the gearbox inspected then it may have already cleared any materials.

    Cheers


  • Re: Metal debris after 25 hours – 2 Engines

    by » one week ago


    I agree with RW. 

    You could change the oil and then go fly and check the magnetic plug every 5 - 10 hours and see if this has stopped during its first 25 hours of use or gets worse.

    Checking the mag plug every 5 hours would be pretty easy.


    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell


  • Re: Metal debris after 25 hours – 2 Engines

    by » 16 hours ago


    What are everyone's thoughts on the need to replace the oil cooler ? The MML states "If the oil circuit is contaminated, replace the oil cooler and flush the oil circuit. Proper judgement requires years of experience in repair of piston engines."

    and my Line Maintenance Course Notes are even more emphatic:

    “It is absolutely necessary to renew the oil radiator if there are any contaminations in the oil circuit or you found chips in the oil filter or on the magnetic plug”

    but CFS says it is not necessary...

    Cheers

    43409_2_MML - Oil Cooler Replacement.png (You do not have access to download this file.)
    43409_2_Line Maintenance Course - Oil Cooler Replacement.jpeg (You do not have access to download this file.)

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