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Which sustainer system would you chose for your sailplane?
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September 26th 12, 11:46 PM posted to rec.aviation.soaring
Chris Davison[_2_]
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Posts: 4
Which sustainer system would you chose for your sailplane?
Think of this in terms of cars, would you rather have an electric car or a
jet
car?? Every pilot out there secretly wants to be a jet pilot...
Benefits? Who cares!
My vote goes for the first technology that can be fitted to a Libelle!
Chris
At 20:33 25 September 2012,
wrote:
Dne torek, 25. september 2012 18:00:15 UTC+2 je oseba Eric Greenwell
napisala:
On 9/25/2012 7:21 AM, Tim Mara wrote:
For performance, low weight, LOW drag, simplicity and safety. JET!
More manufacturers are developing or exploring Jet sustainers. Quite
simply
the lack of moving parts, the very low weight to power output and
when
properly configured to have the computer take the pilot out of
decision
making of the actual operation of the engine the reliability of
operation
make the Jet the best possible solution. The HpH 304 Jet doesn't
require
massive, heavy and possibly hazardous batteries, doesn't require
start-up
and operation or typical reciprocating engines, no priming, no
chocking,
decompressing or diving to windmill and engine to start, no high
parasitic
drag (the jet engine expended has actually less drag than the landing
gear
down), no wind milling propellers, and short time from switch on the
switch
off and stored, literally seconds to start so even at low altitudes
can
be
operational in seconds and without the high drag of a propeller is a
non
issue when it might be necessary to glide the extra distance to make
a
safe
landing with an extended powerplant.
The Jet does have to be engineered right from the start and have
systems
that are completely monitored and controlled by a computer system to
take
the operator error possibility away and this is what has likely
delayed
the
release of the Jet sustainers from most manufacturers. Having flown
just
about al types from simple 2 cycle ultra-lites to small corporate Jet
aircraft I can see potential issues with operators not fully trained
in
Jet
engine operation without the development of a computer based system
to
control the operation of the jet engine. With the HpH system the
controller
monitors all aspects of the engine from start-up to engine cool down
and
stowage, it is simply refined ...
regards
Tim makes some excellent points for the jet sustainer, but every one of
them also applies to the FES. Sure, it's got those "possibly hazardous
batteries", but it does not have those "possibly hazardous 8 gallons of
fuel".
This illustrates the problem with the current voting choices, offered
without any description of each systems attributes. Even a dealer does
not tell us the important differences between two of the three choices,
so how can the average "voter" make an informed choice?
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
I will write here just a few attributes of the FES which I think are the
most important:
-reliable start, full power available in 1s, switching off also very
quick
-no smell in cockpit, no oil on fuselage
-small noise outside and inside of cockpit
-low vibrations
-good max climb rate about 2,5m/s at 22kW for LAK17A (depend on weigh
of
glider)
-very efficient system (only 4kW of power is neccesery for horizontal
flight) which gives about 100km of range
-big advantage is that 12V power is available from main baterie pack,
(DC/DC converter) so you have finally enough power for Radio,
Transponder,
PDA, Vario etc, acctually for the whole flying season
-all 12V Pb batteries can be removed (this mean usually minus 5kg)
-only about 50kg of additional weigh - 5kg of Pb= 45kg
-no change of drag or CG position during engine run
-according Idaflieg test results, drag of propeller blades is really
minimal (official results published in winter)
-very chaep charging of batteries, outside of glider
-virtually maintenance-free
-price in range of Solo sustainers
Articles about FES:
http://www.front-electric-sustainer.com/articles.php
Very good article about recent JETs:
http://www.psr-jet-
system.com/___010_content_EN/___030_Download/20120116_-
_The_Turbine_-_better_than_its_reputation_-_Segelfliegen.pdf
There is not much about Solo sustainers but here is one:
http://www.trb.8m.com/
So now is up to you to take some time to read and decide which one you
would choose!
Regards,
Luka
Chris Davison[_2_]
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