Austro engine reliability and safety

[mfdutra]

I’ll get more details when we can do a better post-mortem.

Hey neema, any news on the post-mortem?

[neema]

Nothing. Checked in with the shop again. Sort of gave up on it.

[neema]

Alright, nudged my shop after Marlon checked in and they had a report to send over.

It's thorough. A whole teardown and inspection: release torque checks, hypotheses on probably cause, photos closely identifying all relevant components, records review, etc

The #4 piston failed with a hole through the top of it and a crack propagating from the top surface down the side. The hole likely a product of the crack. The hypothesis is that my prior set of injectors caused

It had multiple valve bridge cracks in the cylinder head (crack between intake and exhaust valve).

Injectors were microscopically analyzed and all checked out nominal. The blame was on the prior set of injectors that I had. We took a little time to make the injector swap when it was an SB because it was an SB and not an AD. Their hypothesis is that prior injectors were streaking or pooling on the piston head and essentially causing hot spots and the failure took a few hundred hours to materialize.

We swapped one engine's injectors earlier than the other for reasons I can't exactly remember--might have been a shortage of injectors at the time or I was upset about the cost. Unsure. The engine that failed had injectors swapped around 1300 hours engine time.

Interesting observation they made is that my oil temps were notably warmer that what's typically seen. No direct correlation to anything there except mentioning that it couldn't help with respect to fatigue/wear and tear. I always fly in the green arc but the upper end of the green arc gets pretty warm. It gets hot (HOT) in California during the summer. Nature of the beast.

Some pics from the report below:

[Boatguy]

Is the bottom line that the injectors were changed at 1,300hrs instead of the now mandatory 900hrs?

[mfdutra]

Thanks so much neema. I'm really glad they went deep to understand what caused such a catastrophic failure. So now we have a proper evidence as to why we must replace those damn injectors at 900 hours. It's just so frustrating they cost a fortune through Diamond.

[michael.g.miller]

Yeah the markup on injectors is truly criminal, even by aviation standards! I wish they would make the price more reasonable for a required part.

[Soareyes]

Honorable and welcome that they provided you a detailed analysis as compared to say, Continental who would swallow up your broken engine never to be heard from again.

[ememic99]

…Continental who would swallow up your broken engine never to be heard from again.

What’s the basis for this statement?

[Boatguy]

How about posting the entire report?

[neema]

Russ, sorry for the delayed response. Here you guys go.

https://www.dropbox.com/scl/fo/vu57l9a0 ... 42swo&dl=0