Thatcher Smith wrote:
I would be grateful for any opinions, web searches don't seem to reveal
much...

I am considering purchasing a self-launcer, likely in Ventus, ASH26, or
DG808 guise and would like to know:

-do those of you who operate these or similar machines ever lose
soaring days due to malfunctions in the power system?

Fewer than the number of days I have lost because either the tow plane
was broken or I couldn't find a tow pilot.

-are there large price and/or operating cost differentials between
these three?

Yes.

-are there reliaibility differences?

In my opinion, motorgliders are, by their nature, prototypes. DO NOT
expect the level of engineering and reliability that you would
associate with high volume production aircraft. I have seen failures
that made it clear that the manufacturer did not do design testing that
lasted more than a couple of hours of engine time. I would not by a
motorglider that had not been used less than 5 years. Go to a
convention and you will see very pretty machines that look like they
have been meticulously engineered. Wait until you see these same
machines after they have been used 2-3 years!

I am not saying that the engineering is bad (although I can say have
seen examples of bad engineering), it is just that so few of these
things have actually been built that it takes time for the bugs to be
worked out - which is mostly done by the owners!

-are there build quality/longevity differences?

Yes!

-is it difficult to find informed persons to service the power system?

Where do you live? If you are in Europe, no. Elsewhere, yes!

Generally, you will not need to worry about an overhaul, since this
usually takes 25 years of steady use. But there can be failures of
various support systems. I, for instance, had to replace my starter
this winter. The orginal starter motor was no longer available. The
replacement (which, thankfully, I was able to order locally from an
auto parts store!) required fabrication of a new mounting bracket and
machining of two others. A day or two and the job was done. Other
issues have arisen concerning the availability of spare parts for
ageing engines that have been out of production for a number of years.


Thank-you


--
Thatcher Smith