Surely the Austro DA42 is the perfect IFR tourer fie Europe….but nobody seems to motivated by them?
I would say the DA62 is a better prospect. It really does make the DA42 look decidedly average.
However the Diamonds don’t “count” because, like my VW diesel, they have always had turbos 
The “turbo issue” is an issue on the air cooled Lycos and Contis which have problems with heat dissipation at high power settings, causing these engines to have a reduced life.
They also have a low critical altitude. FL120 or so.
The current generation of turbocharged aviation diesels is not “aviation-turbocharged”, they are based on automotive-type turbodiesel engines. Nothing wrong with that, but not quite the same. Car diesels tend to be turbocharged because in a Diesel engine, detonation is not an issue and hence it has a higher overall compression ratio (==> more efficient), more power from the same displacement, and more power at higher RPM where Diesels need a LOT of air (they run very lean).
Yes, but Austro work without requiring clyinder work multiple times pre TBO. The US dinosaur turbos require constant visits to Maintenace faculties to keep working.
Turbos are wonderful when they are part of a reliable system. But if it has mags and a turbo, it’s not reliable – this is the only reason pilots want NA.
Raindeer wrote:
Yes, but Austro work without requiring clyinder work multiple times pre TBO. The US dinosaur turbos require constant visits to Maintenace faculties to keep working.Turbos are wonderful when they are part of a reliable system. But if it has mags and a turbo, it’s not reliable – this is the only reason pilots want NA.
Again I think many here overstate the challenges of turbocharged avgas engines. It isn’t that bad. I think they are more challenging but not to the extent described by some (mostly NA owners).
Remember I have no horse in this race. All of your internal combustion engines are on the brink of failure as far as I am concerned :)
Turbo or not, you can‘t even see us from FL410 ;-)
Jason – didn’t you at one point have a piston PA46? They have the worst possible reputation for this. I used to know a pilot in the USA who used to fly a PA46 full-time doing night organ delivery and they were changing cylinders every few hundred hours. In recent years the wisdom is that operating “deep LOP” addresses this issue well but by all accounts the engines still don’t get anywhere near TBO without chucking the whole top end away.
Peter wrote:
Jason – didn’t you at one point have a piston PA46? They have the worst possible reputation for this. I used to know a pilot in the USA who used to fly a PA46 full-time doing night organ delivery and they were changing cylinders every few hundred hours. In recent years the wisdom is that operating “deep LOP” addresses this issue well but by all accounts the engines still don’t get anywhere near TBO without chucking the whole top end away.
Yes. I had no trouble with the plane at all. Flew it LOP and was careful with temperatures. They typically do need work before TBO that is true. But that may be a cylinder not a full top end. And I think much depends on how you fly them.
PA46 full-time doing night organ delivery and they were changing cylinders every few hundred hours.
Well if you fly balls out with cylinder temperatures in excess of 400℉ all the way to your flight level and lean according to the manual you will get in trouble. It is easy to pick the examples that corroborate your views.
And quite a few of those turbocharged planes are flown by people who do not know a** from t*ts and have absolutely no mechanical understanding. They will fly strictly according to manufacturer’s procedures and lean according to the guidance provided by lean assist without questioning the resulting temperatures. So the engines end up flown with everything forward in the climb all the way to FL200, then in cruise at 85% BHP with CHTs in the very high 300s or low 400s because they are at 100℉ ROP.
Here is my pet example: Mike Busch has had tremendous success with operating his C310s engine to 200% of TBO with IIRC only 2 cylinders replaced out of 12. I am sure there are plenty NA big bore Continentals that require extensive cylinder work way before TBO. I recently saw one (SR22) at a shop in Pontoise with all cylinders out. Even a Lyco IO360 may need cylinder work way before TBO and one I know has had at least 2 cylinders replaced.
So it is not that clear cut. Clearly NA engines are a lot more forgiving than turbos and are harder to trash. Clearly when work needs to be done on a turbo engine you sometimes need to remove intercoolers or admission pipes in order to get to where you need and therefore the maintenance cost will be higher just for that reason, and on top there are more parts to maintain.
Both NA and turbos can be screwed up but turbos are more fragile than NA because it easier to abuse them, and they do cost more in maintenance because there is more hardware under hood.
Whether you want one or the other depends on your flying. In my case I clearly am more happy with the performance provided by a turbo. I looked hard at DA42 for a while because of the availability of diesel and the more robust engines (compared to TSIO550) but in the ended the balance tilted in favour of the TSIO550
