At 17:12 04 June 2006, Eric Greenwell wrote:
While this discussion (which I continue below) is an
interesting one, it
mostly side-steps the RAS response to the announcement
that Lange will
offer an 18 M glider with a gas engine sustainer:

Disappointment.

-To me the disappointing thing is that so much of the
discussion seems to be focused on the motorization
of the self-sustainer version of the Antares 18. There
is a lot more to that aircraft than a way to get home
once you run out of thermals. This aspect seems to
be completely ignored, which is rather strange, since
the goal of gliding is to get somewhere WITHOUT using
the engine.


Nobody seemed excited at the idea that yet another
18 M gas engine
sustainer was going into production, probably because
you can already
get one from Schleicher, Schempp-Hirth, LAK, and DG.
Lange made a
marketing decision, not a technical one, to compete
in this (undoubtedly
larger) market with it's many vendors. They could have
chosen to offer
an 18 M electric sustainer for what I'm sure is a smaller
market, and be
the only vendor, as they did with the Antares.

-As I have tried to explain previously, an electric
self sustainer using currently available (cutting edge)
technology ends up looking very much like the Antares
20E with 18m wingtips. If this is what the market
demands, then why did we have to pull this option from
the market?

The Antares is a very desirable glider, and I would
be very happy with
it. I love the idea, and that is why the Lange 18 M
with a gas engine is
such a disappointment.

-Have you ordered your 20E yet? If the price is the
issue, then:
1: Find out what the real price of the 20E is, the
real bottom line price.
2: Concider that, using current technology, the 18E
price would have to be similar
3: Order a 18S, and wait with installing an engine.






I think this is a very narrow view of what a sustainer
can do and how
they are really used. Don't many European pilots often
take a winch
launch, then use the sustainer to get to lift 20 or
30 miles away?

-And how often do they suffer from engine trouble?

I know some pilots (USA and elsewhere) count on the
sustainer to get them
home in areas where sea breezes and other effects routinely
kill the
soaring near home late in the day. Our club has this
problem, and a
sustainer that provided 3000 feet of climb would be
plenty to overcome it.
Apis and Silent both offer self-launching electrics
with about 1500
meter climb capability. After a typical launch, they
would have even
less climb left than the 1000 meters I suggest would
be adequate for an
electric sustainer. So, there are designers who seem
to think that many
pilots could be happy with much less than 3000 meters
to get home!

-How many Apis and Silent self-launching electrics
do you think have been built? What are their overall
performance.. -As gliders

I am convinced that future technical developments will
allow us to go electrical also for the self sustainer,
but for now the required technology is not available.
Until then, I am afraid we will have to settle on stinky
technology

Andor