Engine reliability

[Paulseaone]

I'm a prospective buyer - I love the DA42/ DA50 / DA62 numbers, they fit my mission perfectly. On Controller.com there are 3+ recent vintage DA62s with one or more new engines. My rough guess is 50% of the used but relatively new DA62s have had engine issues so bad they needed new engines. The need to re-engine an airplane every few years seems like a fatal flaw just on calendar down time, let alone expense.

The DA42 engine issues are well publicized, but it's not clear there either that those new engines are lasting either.

What are owner's experiences here?

[TimS]

There was a recent AD which has caused a lot of engine replacements that was the result of a manufacturing defect.
You are likely seeing the result of this in the market place right now.

Tim

[michael.g.miller]

Welcome to the Diamond forum!

The diesel engines are much more complex than a typical Lycosaurus. They have a gearbox, a turbocharger, and liquid cooling. Before even beginning to talk about the ECUs and associated sensors. So there's a lot more to fail.

In addition, Austro has had a bear of a time taking over manufacturing from Mercedes Benz, with some serious piston issues requiring replacement of a fair number of engines.

I've owned my 2006 DA42NG (re-engined in 2013 to Austros) for ~2 years, with engines around TBR. I'm happy to chat with you about my engine experiences. I've flown my plane around the world and had my fair share of issues.. luckily none too far from civilization.

[Boatguy]

Welcome to the Diamond forum!

The diesel engines are much more complex than a typical Lycosaurus. They have a gearbox, a turbocharger, and liquid cooling. Before even beginning to talk about the ECUs and associated sensors. So there's a lot more to fail.

They also eliminate some common failure points of legacy aviation engines. There are no magnetos, no spark plugs, no lead in the fuel (or oil), and less issues with properly installing cylinders. Oil changes are only every 100hrs. When I was considering the purchase of an SR22T, I was advised by two different shops to expect to do a "top end overhaul" after 900hrs. Austro's also have some major expense at 900hrs when they get new injectors.

Tim and Michael have mentioned the poor transition from MB to Austro manufacturing and the resultant need for the factory to replace a number of engines. Some of those engines not replaced are now on a "watch list" for the duration of their expected life. If you're looking at used planes you should check the serial numbers against the ADs to know if those engines are on the watch list (i.e., monitoring engine oil analysis) There were also some transition problems which manifest themselves in the high pressure fuel pump and oil pump.

Your question opens a pandora's box of controversy. You're going to get lots of comments, mostly fueled by folklore and anecdotes. None of us can provide any factual data because only Austro has the hard data and they don't share.

What we can factually tell you is that an Austro engine has shifted virtually all of the engine management from the pilot to the engine control computers. This was done in automobiles about 40yrs ago. When was the last time you drove a car with a choke? Or a car that didn't have a microprocessor controlling the fuel injection, automatically adjusting each squirt of fuel to the ambient pressure and temperature conditions? The Austro is a modern auto engine in an airplane and it reduces pilot workload. Here's a good example.

This morning I flew from coastal California to Bishop (KBIH). Bishop is at 4,124' nestled between the Sierra's and White Mountains, each rising sharply to 14,000' on either side of the Chalfant valley in which Bishop is located. I crossed the Sierras at 16,000' and descended to KBIH by pulling back the throttles and dropping the nose to 800fpm. No concerns about shock cooling, no changes in mixture along the way, no engine management. I dropped off my wife about 10:30am as the day was beginning to warm up, and departed with a DA of 6,000' +. I climbed straight from 4,124' to 16,000' at 1,000-1,200fpm with my power initially at 94% burning 18.4gph. Somewhere around 14,000' the power gradually dialed back to around 88% under engine computer control. No step climbs, no cooling issues, no mixture changes, no engine management. When I arrived at 16,000' I pulled the throttles back to 75% and cruised home burning a total of 14.4gph with a TAS of 180kts (and a 20-35kt headwind component as a I rode some mountain waves). You can look at it yourself on FlightAware.

[mfdutra]

I had 4 years of Cirrus ownership before moving to a new DA62. No matter how much I write here, I can’t describe how much better is to operate these Austro engines. The Cirrus was a nice airplane and I really like it, but I don’t miss those engines. It’s 2023 and people are still suffering to hot-start, monitor CHT, EGT, finding the right mixture, careful not to run in the red box, wasting an absurd amount of fuel so the engine doesn’t melt on climbs, dealing with magnetos breaking all the time, fouled spark plugs, lead contaminating everything. No thanks!

I’ve had a cylinder blow up in flight, resulting in an emergency landing. Engine on warranty. Cirrus showed the middle finger and didn’t pay anything.

We’ve discussed innumerable engines failures on COPA, for all sorts of reasons. Most CAPS pulls are because of engine failures.

Don’t expect the Austros to be of any turbine reliability. But Continental and Lycoming aren’t any better either.

Just pray for not having an engine failure right after takeoff. Once you have some height, an engine failure on a Diamond twin is merely an inconvenience, if you are well trained.

[TimS]

I had 4 years of Cirrus ownership before moving to a new DA62. No matter how much I write here, I can’t describe how much better is to operate these Austro engines. The Cirrus was a nice airplane and I really like it, but I don’t miss those engines. It’s 2023 and people are still suffering to hot-start, monitor CHT, EGT, finding the right mixture, careful not to run in the red box, wasting an absurd amount of fuel so the engine doesn’t melt on climbs, dealing with magnetos breaking all the time, fouled spark plugs, lead contaminating everything. No thanks!

I’ve had a cylinder blow up in flight, resulting in an emergency landing. Engine on warranty. Cirrus showed the middle finger and didn’t pay anything.

We’ve discussed innumerable engines failures on COPA, for all sorts of reasons. Most CAPS pulls are because of engine failures.

Don’t expect the Austros to be of any turbine reliability. But Continental and Lycoming aren’t any better either.

Just pray for not having an engine failure right after takeoff. Once you have some height, an engine failure on a Diamond twin is merely an inconvenience, if you are well trained.

Just curious, because I believe you switched in the last couple years.
Skip the capital cost aspect. How do the Diamond Twin and SR22 compare in terms of operating costs with and without an engine reserve?
For a very long time, even as CMI/Austro have improved the engines, the general consensus was the OpEx of a DA-42 and a SR22 without reserve gave the edge to the Diamond while including the reserve the edge went to SR22. In both cases, the edge was only a few percentage points, so it was not significant. (This was using schedule maintenance numbers)

Tim

[Rich]

The Austro is a modern auto engine in an airplane ...

Well, sort of. In this century I have owned 3 motorcycles, 2 pickup trucks, 1 straight gas engine car and 2 Prius's (Prii?). I still own a motorcycle (30,000 miles), a pickup (180,000 miles) and a Prius (72,000 miles-previous one traded in at 128,000) - all have ECU's, the Prius and the bike having the most onboard computer involvement. In all those years and hundreds of thousands of miles of the previous and current vehicles in all kinds of weather, the engine components that have been replaced:

Maybe 3 sets of spark plugs.
Nissan Distributor caps. This was the previous pickup that had a funky dual-ignition system.
A couple of alternator belts.

That's it, other than regular oil changes and occasional air filters and coolant flushes. Of course, I don't have to deal with leaded fuel, but I do run the much-maligned ethanol-tainted fuel virtually all the time.

The Austro may be nominally a modern engine, but it falls well short of what we expect of our cars and bikes.

BTW, comparing Austro reliability with big-bore, high power Continental engines is quite a low bar.

[michael.g.miller]

The Austro may be nominally a modern engine, but it falls well short of what we expect of our cars and bikes.

BTW, comparing Austro reliability with big-bore, high power Continental engines is quite a low bar.

To be fair to Austro, we are asking a LOT out of the engines. The ability to operate at 168 hp for an engine designed to max out at 135hp. The ability to routinely operate at 75% power (.75 * 168 = 126hp). That's like operating your car with the pedal to the metal for 2-3 hours each week, with significant temperature / pressure variations. Of course that's no excuse - Austro should have beefed up the engines to support the power, and their solo manufacturing efforts would make Daimler roll in his grave.

But the way in which we operate the engines certainly can explain some of the issues facing Austro engines. I try to operate mine at 60% power ~= 100 hp, to keep it within the parameters of the original engine.

[mfdutra]

Just curious, because I believe you switched in the last couple years.
Skip the capital cost aspect. How do the Diamond Twin and SR22 compare in terms of operating costs with and without an engine reserve?
For a very long time, even as CMI/Austro have improved the engines, the general consensus was the OpEx of a DA-42 and a SR22 without reserve gave the edge to the Diamond while including the reserve the edge went to SR22. In both cases, the edge was only a few percentage points, so it was not significant. (This was using schedule maintenance numbers)

I've only had the DA62 for 6 months, so I can't speak for maintenance yet. And the Cirrus was also new and under warranty, so no big surprises besides the cylinder blow up and they decided it was operator error (repulsive), but it cost me like $3500 to fix.

The incremental cost of a flight on the DA62 is cheaper, as it's more fuel efficient, fuel is cheaper and the oil lasts 4x more. Some people change oil in the Cirrus every 50 hours, but I preferred more like 25-30 hours.

On the engine reserve side, you can't really take 2000 hours out of an SR22T. You're going to do cylinders once or twice before overhauling the engine. Those engines run really hard all the time. An engine swap or overhaul is more expensive than a new Austro, but you only have one to do.

On maintenance in general, the DA62 has an extra powertrain, so it will cost more for sure. It's like having two kids instead of one. And it's more complex, with gear boxes, retractable gear, radar, etc.

IMO, the additional capex and opex of owning a DA62 is in line with the additional capability and utility the DA62 provides.

[krellis]

I had 4 years of Cirrus ownership before moving to a new DA62. No matter how much I write here, I can’t describe how much better is to operate these Austro engines. The Cirrus was a nice airplane and I really like it, but I don’t miss those engines. It’s 2023 and people are still suffering to hot-start, monitor CHT, EGT, finding the right mixture, careful not to run in the red box, wasting an absurd amount of fuel so the engine doesn’t melt on climbs, dealing with magnetos breaking all the time, fouled spark plugs, lead contaminating everything. No thanks!

I’ve had a cylinder blow up in flight, resulting in an emergency landing. Engine on warranty. Cirrus showed the middle finger and didn’t pay anything.

We’ve discussed innumerable engines failures on COPA, for all sorts of reasons. Most CAPS pulls are because of engine failures.

Don’t expect the Austros to be of any turbine reliability. But Continental and Lycoming aren’t any better either.

Just pray for not having an engine failure right after takeoff. Once you have some height, an engine failure on a Diamond twin is merely an inconvenience, if you are well trained.

My Lycoming (experimental airplane) has push button start and EFII - so it starts just like my car, hot or cold. iE2 is available from Lycoming (granted only on a few engines) - but the technology exists. Magnetos are pretty reliable if maintained and spark plugs generally won't foul if you lean properly (especially on the ground). Fine wires help a lot too.

As to Cirrus giving owners the finger when their engines failed - ask the Diamond owners what they experienced with Thielert. As was pointed out, the airframe warranty does not cover the engine. Standard practice in GA.

We have little to no idea about Austro reliability, since the fleet size is still relatively small and Austro doesn't release much data. Still it seems like there have been multiple issues with ECU's, coolant leaks, fuel injectors, cylinder heads, pistons, etc. Plenty of reports on this forum about Austro failures. NA Lycomings and Continentals are very reliable. The turbo models less so.