Diamond DA42 reliability

Hello Forum. I have placed my order for a DA42 and been promised delivery by August this year, so with normal delays and paperwork hiccups, I should be legal to fly by October at the latest. I have also decided to accompany the ferry pilot from Vienna to Thailand as this will be a great way to get familiar with the aircraft.

The bad news is that since placing the order, I am hearing some pretty dire reports about the general reliability of this aircraft. What I have heard so far is:-

To much reliance on the battery to run the engines. (I know this has been partiality addressed since the infamous landing gear crash.)
Gearbox failures.
Poor cooperation between the engine manufacturer and Diamond.
Poor availability of spares.
Swap out of gearboxes at 300 hrs
Swap out of Engines at 1,000 hrs

I got most of the above from two different UK companies who between them own 5 DA42s, and who told me that they could not recommend it at all. They have owned the aircraft for two years, so clearly these are older versions with the 1.7L engine, not the newer 2.0. I am willing to believe that any new design will have teething problems which over time get resolved, but I would really like to hear from current owners about what their experiences have been so far.

On paper this aircraft looks great for what I want, but I am worried I may end up with an unreliable expensive aircraft.

If you own a DA42, I would like to hear from you. Please also include how many hours you already have on the aircraft.

Many thanks in advance.



I do not own a DA42, but had dinner last night with a friend who does. He said that support for any engine problems has been very poor. It has gotten so bad that Diamond has announced that they will build their own engines in the future. There was a very good article about the situation in Aviation Consumer, suggest that you give that a read. They did a survey of Thielert engine owners (in all aircraft), and a summary of that survey was:

[quote=“Aviation Consumer”]What emerged was a sharp-edged dichotomy. On the one hand, owners seem to love the Diamond airframes and generally give the company praise for customer support. And every owner we communicated with seems enthralled with the idea of economical diesel power. But the majority told us they found the reality of diesel reliability to be a disappointment.

Googling DA42 and reliability revealed a Canadian AD.

tc.gc.ca/aviation/applicatio … 7-0182.pdf

No DA42 experience here.


Thanks, the article kind of confirms what I have been hearing, although to be fair it relates to the 1.7L engine.

I would like to hear from anyone using the newer 2.0 engine, to see if this has addressed the issues raised.


Probably a little early for data points on the 2.0 engine?

One article I read shows the engine was announced to be installed in the DA42 in February 2007? 11 months not that much time assuming that first 2.0 engine was even flying

avweb.com/eletter/archives/a … tml#194362


The College flight training program in Provo, UT has some & I understand that they have the newer engines. Google UVSC aviation and you could get an email address to contact them.

Diamond CEO said that they know of 22 in flight stoppages…

22 ?? Blimey !! I don’t wan’t that shit!!

The DA42 is ugly, slow (they promised 200kts but 150kts is more like it), and the engine’s are really really bad. I doubt they can fix all that in the 2.0, besides, even with the 2.0 version: if you have an complete electrical faillure, your engines are BOTH gone… i don’t like that feeling. I rather like the old WWII design of dual magneto’s and everything else can fail but your engine will keep on running…

You’d think with a diesel that it would be rock solid and run forever even without electricity. I have an old Benz with 400,000 running strong and it’ll keep chugging away with out an alternator or battery. I guess its the whole FADEC thing. I suppose if its reliable enough for turbine aircraft, you’d think they’d manage to get it working for a piston.

I can tell you though that she does run beautifully on a single engine.

Very interesting picture. What camera settings / lens type did you get to get both the engine and background sharp at whatever speed that plane flies?

Usually close ups of the engine like that leave the background blurred and also the ground wouldn’t be that crystal clear just from moving?

First impression was the engine was superimposed over the background somehow as depth of field looks unrealistically crystal clear.


You just need to take the photo either with the largest aperture (lowest f-stop) your lens can do and/or in the brightest light possible. The combination will let you have a really low exposure time so there’s no blur. Minimal/no zoom helps get a lower f stop too if you’ve got your camera on auto.

This particular photo I used my Sony DSC F717.


Plus I addes a century optics wide angle adapter.

With a narrow aperture and the wide angle lens the depth of field was increased to keep the focus near infinity.

I understand that is being fixed very quickly with the addition of a back-up battery which allows the flight to continue even with both alternators failing. The only case where the engines failed when both alternators failed was in a plane which had a completely dead battery, which they jump started, and then had an alternator failure. You should not fly any airplane, even with dual magnetos, with a dead battery, as an alternator failure in most singles (which only have one alternator) will leave you with no electronics. (The engine will keep running.)

What he said, except I think you want a high f-stop, or closed aperture. But that cans till be accompshed with bright light and minimal zoom.

But in this particular picture, there’s no blur because the prop is stopped.

Just pull your mixture all the way back and then snap the picture.

Except the prop won’t stop in Allen’s sundowner, it’ll most likely just windmill.

I figured no prop blur since the engine was off, it was the no ground blur that intrigued me.

I figured to reduce or eliminate the ground blur from motion it would take a higher then normal shutter speed but that usually darkens the picture from lack of exposure.

The trick to the picture really was the wide angle lense :smiley:

And very nice picture considering you don’t get the “fisheye effect” most commonly seen in wide angle lense pics.


No feather prop option in my Sundowner so I’d suspect it would windmill.

My luck Waz is that it wouldn’t “relight” when going full rich :smiley: so I will leave that to those braver then me.

Or take up gliding that doesn’t require a prop!


Just barely noticeable, but look closely and you can see the curvature of the earth… at what… only 2,000 feet! :smiley:

I noticed that but I was “guessing” the altitude to be around 5 to 7K based on the size of the farm houses.

Of course, even at 5K, you don’t exactly see the curvature of the earth :smiley:

Good photo contest, guess the altitude :laughing:

And only Magnetoz has that answer!


Yeah - your guess is probably closer than mine.