Diesel vs Lycoming

[Manfred]

I have been reading through the forum for a while and have to say: very, very useful information here.
And a very friendly environment !

I am about to buy a DA40. I have some 500 hours in my Motorglider (Stemme) and other planes (C172, PA32) and will get my IFR rating soon - I hope. I am looking for an IFR trainer (to practice IFR flights after I got my rating) before moving up to an DA42 in some years ...

Flying the Stemme with a glide ration of 1:50 any engine failure (except after the first minutes after take off) on a Stemme would be a non-event as I do ALL my landings with power off. Hence I am a bit paranoid using a normal single engine plane. I was first looking into the Cirrus SR20 (because of the parachute) - but two feature of the DA40 are too temping:
- short field capability
- very docile flight characteristic
The latter will be probably as big a safety feature as the parachute: a substantial number of fatal accidents occur flying in the traffic pattern (low and close to an airport: stall / spin). Here, a parachute is useless. And the Cirrus more dangerous.

However, having to rely on an engine, I would feel more at ease using a Lycoming compared to an Austro Diesel. But that is just a gutt feeling. I my opinion the diesel needs too many auxiliary parts to keep it running (electricity, ECU, fuel pump, + ?). The Lycoming needs only one magneto (one out of two) to get me to the next airport.

Having said all this:
How is your opinion about the reliability of the Austro Engine (I would not consider Thielert) versus Lycoming.

Thanks for your input !

Manfred, Koblenz (Germany)

[Kai]

Manfred,

if the DA40NG seems tempting to you because of the short field capability, it seems the difference is only 80 metres take off roll to the SR20. Nevertheless, a DA40 is always a better option for people who focus on safety. Much has been speculated about the reasons why the DA40´s safety record is so much better than of a Cirrus SR20. Personally, I believe the DA40 attracts better pilots, has a lower landing speed and in a DA40 you don´t do shit just because you have a parachute.

When it comes to comparing the reliability of a Lycoming to an Austro Engine, you are comparing one of the oldest and most tested engines to a very new one (in aviation terms). I cannot give you any help here on the Austro Engine but inflight engine failures were few and it seems the NG-operators are quite happy with it.

This thread might be of interest to you: viewtopic.php?t=5468

[robert63]

Manfred,

each person has a different approach to safety.
You say that an engine failure with the Stemme is a non-event and I absolutely agree except if this happens over the North Atlantic and no land within reach.
Flying a single engine aircraft over flat land and during the day is also pretty safe, even though a lot of fatal accidents happened under such conditions. I am scared of flying a single engine aircraft during night and/or IMC conditions with fog on the ground and this is the reason why I have a DA42. I'm also scared of flying into embedded CB which happened once and then I needed on board weather radar plus satellite weather.
We flew nearly 500 hours during the last 2 years in our DA42NG which is then 1.000 hours of Austroengine time and there was no issue at all. I think the DA42NG is a very safe airplane, however, several fatal accidents occurred as with almost any other aircraft. You have to find your acceptable safety level for yourself and need to balance it with what you can afford. If money is no issue a triple engine jet aircraft with a safety pilot always present would be quite safe.
A Lycoming engine might be a little bit safer than the Austroengine but still an engine failure may occur any time. There was a very interesting article in the recent German "fliegermagazin" about an Austrian couple flying a C182 from Arizona to Argentina doing 46 legs in 15 countries and 16.000 NM. They flew over sea and areas with no chance for a safe landing without any problems, but 5 minutes before the final touch down in Florida their engine quit overhead the city, they crash landed on a street and luckily survived with minor injuries.
They are planning for a new trip, but this time in a Seneca with 2 engines.
Apparently their safety levels changed due to experience and they are considering a twin engine aircraft to be safer than a single engine which was acceptable before.
IFR single engine operation is rather safe during daylight, over flat land and with not too low ceilings. Then I think that the Austroengine is equally safe than the Lycoming.
IFR operation during the night with low ceilings leaves you with no options in case your single engine quits unless you are really high and have an IFR equipped airport really close plus you need to be a very good pilot.
To put yourself into such a condition requires that you are willing to take a high risk, no matter what kind of engine it is. Any engine may fail and since there is almost no option the outcome will be catastrophic.
Even though I consider our DA42NG a very safe aircraft we use survival suits and life rafts on long oceanic flights just to have options in case that the very unlikely happens.
So it is all about never running out of options and you can figure it out by yourself.

[Manfred]

Thanks for your opinions so far.

Yes, very true: running out of options is the real problem. High Reliability is only postponing the point in time when you better do have an option to get down safely.

However I think that this post is pointing to some issues with the Austro Engine:
viewtopic.php?f=17&t=5638


Manfred

[Ajh]

Hi Manfred,
Your focus is safety. Out of curiosity, do you think the Thielert is less reliable than am Austro?

[robert63]

Yes, but as Kai said it is a very new engine speaking in aviation time frames. My feeling is that it performs very well when taking this into consideration.
We couldn't have done some of our trips due to Avgas unavailability, our flying cost would be much higher due to high consumption and high price. We like that we can fly an approach with full power until 2 miles final and have no issues with shock cooling. And I enjoy that it always starts immediately no matter if hot or cold. My feeling is that in total we get a better deal with the AE. And a somewhat lower failure rate doesn't solve the problem of a catastrophic outcome in case that it happens. I don't like to sit in an aircraft for hours during night and heavy IMC and watch the engine instruments praying for no failure and sweating at the slightest changes in sound.

[ThomasD]

Manfred,

And BTW, my experience is that the Lycoming DA40 is well powered (particularly with the PowerFlow exhaust) whereas the Diesel versions are quite underpowered - particularly important during take-off I feel (where you want to get as high as you can as fast as you can).
I have found that the Lycoming does ~140KTAS at 8.1 USG/hr @ FL100, so is reasonably efficient. I must admit, as a safety feature I also like the fact that it runs with no external electrical input and no fuel pump running (I have tried switching off the master switch & alternator on the ground - not a hiccup at all)
And any maintenance shop is familiar with the Lycoming and it may be cheaper to maintain than either Diesel?
(And the Lycoming probably has a longer TBO and I think quite a bit cheaper to replace than either the Austro or the Thielert, when the time comes so this offsets a reasonable amount of the extra fuel cost of AVGAS - apologies, not tracked the Diesel engines so my comments may be uninformed - someone on here may have done the maths to see what the difference in total running cost is over 2,000 hours?)

If you plan to fly a lot to places with limited or no AVGAS then that makes the decision for you of course, but otherwise from a personal viewpoint I am more comfortable with the Lycoming with regards to reliability (based upon my limited understanding and experience).

Tom

[Erik]

Is there a financial reason why DA40 first or is it a pilot training reason?

With your experience, I would think it reasonable to simply move straight the DA42 and train in that airplane you plan to own and fly for a long time. Then the rest of the question is mute.

[Manfred]

Hi Erik !

I am new to the IFR world. I don't even have a IFR rating today. Maybe I don't like it ? In that case I rather have made a investment in a DA40 than a DA42.
And, hey, let me have something to look foreward to after I bought the DA40

[Erik]

Ah - if you might not like it - then sure - dip the toe in first.

Believe it or not - it is possible to get a ME rating ONLY on a license and then you would not even be allowed to fly SE. There exist people with that kind of rating.