Bad time to have a Mag problem

[airborne]

Picked up my 2010 XLS from its second annual on Friday (at KHGR). Normally I would make a quick hop back to KJYO as a shake down, but had to go 250 miles south with the wife and a neighbor for a funeral. VFR trip went fine, and the airplane performed well. Yesterday, we had to make the return in IMC. I was in the soup at 1,500 ft and climbing to 5,000 when I caught a little hesitation in the plane. Everything was green, but it just didn't seem quite right - temps were a bit off and I stayed rich. Being in rain and IMC didn't help for the 1.5 hour trip back to KHGR.

Finally broke out and landed with my passengers. Opened the canopy and put my hand on the sill to exit, only to get a palm full of fresh oil. Stepped out to see the left side of my bird covered in oil exiting from under the cowling. Inspection revealed the outboard retention nut and clamp missing from the magneto. The unit had begun backing away from the engine housing, hence the oil bath. Some folks take great comfort in dual mags, but if the unit comes away from the drive gear, it will get quiet in a hurry. Needless to say, I was not pleased to have been IMC with this going on up front.

Amazingly, the retention nuts are not wired, but utilize a star washer and only 17 ft-lb torque. I found an old Service Instruction (not for DA40) that illustrates this problem on Mooney/Cardinal.
http://www.lycoming.textron.com/support ... I1508B.pdf

Word to the wise, pull your cowling every so often, and never assume an annual means your plane is 100% healthy!

Safe flying

[CFIDave]

Really glad things turned out OK.

I *used* to take our plane to the same place (HAS at KHGR?) for service back when our plane was under warranty, since they were a Diamond Service Center. But went elsewhere after multiple poor repair/maintenance issues with them occurred -- none as serious as yours or faults happening while flying.

Unfortunately many other places or independent A&Ps I've used for maintenance over the last 3.5 years of ownership have also resulted in shoddy/incomplete/incorrect work, including:
- an incorrectly-timed mag that fired on the exhaust stroke (creates a nice backfire!)
- destroyed chrome on the spinner due to use of the wrong tape to protect against cowling scratches (shop had to buy me a new spinner)
- a prop that leaked grease right after being serviced to replace MT blades (a prop shop did this)
- re-mounting of a prop "upside down" from original so that a new dynamic balance was needed
- when installing new mags, rewiring of the ignition system so that the Slick Start was disabled and the aircraft wouldn't start in the winter (which the shop tried to claim was "pilot error" in not knowing how to start the plane!)

As each of these issues was fixed, I got "educated" more about the plane. But what was really instructional was participating in an "owner-assisted annual" last year, where I got to help take much of the plane apart and put it back together. As a result I now feel comfortable changing my own oil/filter and have replaced spark plugs. If you've got the time, I highly recommend participating in the annual inspection process.

[Steve]

As each of these issues was fixed, I got "educated" more about the plane. But what was really instructional was participating in an "owner-assisted annual" last year, where I got to help take much of the plane apart and put it back together. As a result I now feel comfortable changing my own oil/filter and have replaced spark plugs. If you've got the time, I highly recommend participating in the annual inspection process.

Doing my tenth owner-assisted annual right now. I couldn't agree more. Nothing like having two sets of eyes looking at each critical item. I also do my PMCF (Post-Maintenance Check Flight) in VMC, and in close proximity (gliding distance) to my field. The next flight is a 40-50 NM hamburger run, before I consider the aircraft "cleared" for all operations.

Steve

[GLDAS]

That Cardinal / Mooney M20K (201) configuration is the single shaft driving two mags. It's redundant-ish. Had you lost the shaft in a 201, you would have known right quick! Of course, the single shaft has half the likelihood of failure, so maybe it's more reliable! Mr. Market thinks otherwise, it seems, since that configuration is not in widespread use. Here are J. Mac's thoughts on the topic http://macsblog.com/2012/11/is-one-and- ... gs-enough/

-dan
dan@greatlakesdiamond.com

[airborne]

Dave

Who did you go to for your owner-assisted annual? That is a great option for some peace of mind...

[CFIDave]

Dave

Who did you go to for your owner-assisted annual? That is a great option for some peace of mind...

Someone I know recommended an independent inspection-authorized mechanic (based at KHEF Manassas) who was willing to come to my hangar at KJYO to perform the annual inspection there. The good news was that he was less expensive and the annual went very well as we relied extensively on the DA40 Aircraft Maintenance Manual (AMM). http://www.diamond-air.at/da40-180_amm_ ... 73ab0.html

The bad news is that a few months later when I used him to time a mag, he caused it to fire during the exhaust cycle and create engine backfires during an engine runup. I had to pay Landmark at KJYO (now ProJet) to re-install the mag and time it properly. After that experience I obviously wouldn't recommend this mechanic again.

I'm still trying to figure out what to do for my annual next month, but ProJet at KJYO and Aero Services at KOKV have both told me they permit owner-assisted annuals; I'm likely to try one of them. Since the plane just turned 5 years old, it will also require the dreaded rudder cable replacement.

[Rick]

I'm still trying to figure out what to do for my annual next month, but ProJet at KJYO and Aero Services at KOKV have both told me they permit owner-assisted annuals; I'm likely to try one of them. Since the plane just turned 5 years old, it will also require the dreaded rudder cable replacement.

Dave, half an hour SW of you, at KSHD, is Classic Aviation. They are a Diamond Service Center, and I have been doing owner-assisted annuals there since 2008. They did the rudder cable replacement on my '04 (as well as several others I know of), and are a joy to work with and very reasonable. PM me if you want more info.

[Lance Murray]

So much for torque specs, ground run and leak check.