At 14:52 08 January 2016, Charlie M. UH & 002 owner/pilot
wrote:
On Friday, January 8, 2016 at 1:40:33 AM UTC-5, Surge
wrote:
On Thursday, 27 September 2012 00:06:31 UTC+2,

wrot=
e:
For me electrical sustainer in a glider is the perfect
solution. It
lin=
ks in to the spirit of the sport, better than a turbine. But
the propeller
=
on the nose feels slightly off.... Especially when you
consider the
bugwipe=
r garages becoming standard on the top sailplanes. We are
spending more
and=
more on reducing drag. Then this minor addition feels
going against the
fl=
ow. Why not a small pylon with this nice foldable propeller
you have
engine=
ered? Or am I the only one who has this uncomfortable
feeling?
=20
How about FES in an EDF (electric ducted fan)
configuration instead of
py=
lon mounted FES? The EDF could be mounted in the
fuselage with doors than
o=
pen and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon
mounted system?
Would a smaller prop size make it less efficient and
impractical?
The one advantage would be the removal of most of the
pitching issue
asso=
ciated with pylon mounted systems.
=20
If I had the money for a self launcher or sustainer
equipped glider it
wo=
uld be FES due to simplicity, reliability and safety.
From a safety perspective I presume a battery fire would
tend to be more
=
isolated in a crash whereas with combustible fuel you and
the glider could
=
become engulfed in flames within seconds as fuel is
splashed around.
As battery and fuel cell technology advances, alternative
energy storage
=
upgrades could be a possibility without having to purchase
another glider.
I don't like the smell of gasoline or jet fuel nor the
complexity with
th=
ings that operate at high temperatures and need to be
maintained
regularly.=
A brushless electric motor can literally run for years with a
decent set
o=
f bearings. That means less hassle and maybe lower
maintenance costs over
t=
he long run depending on the battery technology being
used.
=20
A sustainer option would suite me perfectly. I don't need
to operate
auto=
nomously and a winch launch to 1500 feet is cheap ($4.70
USD) and
preserves=
power for when I may need it.

With retractable gear, mixers/controls, etc., not much room
for a decent
si=
zed EDF. Unless of course, you want to make the fuselage
larger, but that
a=
dd's wetted area and reduces the performance.


I'd agree with most of the above: gasoline is certainly a
hazard in a crash but Lithium batteries are not exactly "safe"
in a crash, they too can burn and the combustion products
are very hazardous. Then there's the problem of several
hundred volts DC at large...
See:
http://www.bea.aero/fr/enquetes/2012/2012.semaine.36.pd
f