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Which sustainer system would you chose for your sailplane?



 
 
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  #21  
Old September 25th 12, 04:21 AM posted to rec.aviation.soaring
bumper[_4_]
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Posts: 434
Default Which sustainer system would you chose for your sailplane?

On Sunday, September 23, 2012 10:16:30 AM UTC-7, John Cochrane wrote:



From an engineering standpoint, I don't really see why the electrics

don't also charge the battery. If you climb to 3000', in 20 minutes,

surely running the prop in generator mode for 20 minutes or so,

doubling your sink rate temporarily, should recharge the batteries?

This could make a 3000' capacity enough for self launch and

retrieve!.



John Cochrane


John,

I'm not an engineer by any stretch, but your question seems to presume 100% effeciency. Even under ideal circumstances propellers are closer to 80% - - so that would be at least a 20% loss on both discharge and charge.

Then there's the heat loss due to friction and resistance of leads and internal motor windings. Couple that with battery heat generation and loss due to internal resistance and chemical processes on both charge and discharge. All this may have one pointing downhill charging batteries for longer than might be comfortable. I get uncomfortable just thinking about it (g).

bumper
ASH26E . . . like those old Mazda commercials, Wankel engine go MMMMMMMMMMMMM!
  #22  
Old September 25th 12, 04:34 AM posted to rec.aviation.soaring
Craig Funston[_2_]
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Posts: 115
Default Which sustainer system would you chose for your sailplane?

On Saturday, September 22, 2012 10:55:27 PM UTC-7, wrote:
Dear gliderpilots!



Manufacturers are not completely sure which is the way to go. So here you can vote for your favorite sustainer system:



http://www.front-electric-sustainer.com/voting.php



Thank you,



Luka


Regenerative energy derivation from soaring flight has actually been looked at fairly seriously. This is an interesting read on the subject
esoaring.com/regensoaring.pdf

Craig
  #23  
Old September 25th 12, 03:21 PM posted to rec.aviation.soaring
Tim Mara
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Posts: 375
Default Which sustainer system would you chose for your sailplane?

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
Please visit the Wings & Wheels website at www.wingsandwheels.com


wrote in message
...
Dear gliderpilots!

Manufacturers are not completely sure which is the way to go. So here you
can vote for your favorite sustainer system:

http://www.front-electric-sustainer.com/voting.php

Thank you,

Luka



  #24  
Old September 25th 12, 05:00 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
external usenet poster
 
Posts: 1,939
Default Which sustainer system would you chose for your sailplane?

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)
  #25  
Old September 25th 12, 08:43 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 18
Default Which sustainer system would you chose for your sailplane?

Dne nedelja, 23. september 2012 07:55:27 UTC+2 je oseba napisala:
Dear gliderpilots!



Manufacturers are not completely sure which is the way to go. So here you can vote for your favorite sustainer system:



http://www.front-electric-sustainer.com/voting.php



Thank you,



Luka


  #26  
Old September 25th 12, 08:45 PM posted to rec.aviation.soaring
Chris Nicholas[_2_]
external usenet poster
 
Posts: 197
Default Which sustainer system would you chose for your sailplane?

I have a Lak 17A with FES. I had the glider already, so a retrofit
sustainer was the only option. I chose the FES for those features which are
undoubted advantages compared with an internal combustion engine/pylon. My
reasons and the outcome are set out in two articles which are available on
Luka’s website.

For somebody contemplating a new glider, or for a manufacturer
contemplating choices between one route and another, I think there are a
number of unknowns. These include the reliability in starting in the air,
general reliability, relative safety, hazard warning, longevity, ongoing
maintenance costs, battery replacement costs, etc..

My personal opinion, based on very limited numbers of FES and jet, but
rather larger numbers of internal combustion engines, is that:

FES reliability is unproven, but I have no reason to think that it will be
anything other than good. I have a friend with a Lak with a sustainer
engine who has landed out several times after it failed to start in the
air, with of course a considerably higher decision than the FES needs. The
jet is claimed to have a low decision height and quick start up, but I have
heard of one user who is onto his third engine which does not sound like
good reliability to me, if true. I have no idea whether the jet is close to
100% reliable starting in the air.

Lipo batteries based on model aircraft flying and some other applications
have a reputation for occasional disastrous fires. The FES system has
temperature sensors and warnings which give me some comfort. I have a
photograph of fire damage caused to a glider with an internal combustion
engine. The pilot did not know until he was landing or had landed that it
was destroying the fuselage behind the wing. He was very lucky he was not
cruising high at the time. I suspect that the jet has too little service as
yet for anyone to know whether it is better or worse.

FES Battery replacement costs are likely to be 200-500 units of currency a
year on average, maybe less. Electric motors are usually very reliable. I
don’t know about the control system. My friend with the internal
combustion engine is having cracking problems with his exhaust system.
Others have too. I don’t know what other routine or sporadic maintenance
costs are involved. I don’t suppose anyone can say what they will be for
the jet, although for someone to be on his third motor is not an
encouraging sign.

I’m certainly very happy with my decision. The range is okay, as an early
adopter I don’t have some of the features now available, but it was the
right decision for me at the time. For other people, and in the future,
there may be good reasons for different choices. In my opinion, nobody can
yet know.

Chris N



  #27  
Old September 25th 12, 08:47 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 18
Default Which sustainer system would you chose for your sailplane?

To what altitude can the LAK climb?

LAK17A FES can climb about 1500m
LAK17B FES can climb 1250m

Regards,

Luka
  #28  
Old September 25th 12, 09:18 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Which sustainer system would you chose for your sailplane?

In the US, the FAA required a type rating for any turbine-powered aircraft.
Lately, it seems, they now a Letter of Authorization, to fly a jet powered
glider. This letter must be renewed annually with a checkride. Seems a bit
extreme for me.

Note: My information about the jet glider comes from an acquaintance who
just checked out in the Bonus Jet self-launch glider based at Moriarty, NM.


"Chris Nicholas" wrote in message
...
I have a Lak 17A with FES. I had the glider already, so a retrofit
sustainer was the only option. I chose the FES for those features which
are
undoubted advantages compared with an internal combustion engine/pylon. My
reasons and the outcome are set out in two articles which are available on
Lukaâ?Ts website.

For somebody contemplating a new glider, or for a manufacturer
contemplating choices between one route and another, I think there are a
number of unknowns. These include the reliability in starting in the air,
general reliability, relative safety, hazard warning, longevity, ongoing
maintenance costs, battery replacement costs, etc..

My personal opinion, based on very limited numbers of FES and jet, but
rather larger numbers of internal combustion engines, is that:

FES reliability is unproven, but I have no reason to think that it will be
anything other than good. I have a friend with a Lak with a sustainer
engine who has landed out several times after it failed to start in the
air, with of course a considerably higher decision than the FES needs. The
jet is claimed to have a low decision height and quick start up, but I
have
heard of one user who is onto his third engine which does not sound like
good reliability to me, if true. I have no idea whether the jet is close
to
100% reliable starting in the air.

Lipo batteries based on model aircraft flying and some other applications
have a reputation for occasional disastrous fires. The FES system has
temperature sensors and warnings which give me some comfort. I have a
photograph of fire damage caused to a glider with an internal combustion
engine. The pilot did not know until he was landing or had landed that it
was destroying the fuselage behind the wing. He was very lucky he was not
cruising high at the time. I suspect that the jet has too little service
as
yet for anyone to know whether it is better or worse.

FES Battery replacement costs are likely to be 200-500 units of currency a
year on average, maybe less. Electric motors are usually very reliable. I
donâ?Tt know about the control system. My friend with the internal
combustion engine is having cracking problems with his exhaust system.
Others have too. I donâ?Tt know what other routine or sporadic maintenance
costs are involved. I donâ?Tt suppose anyone can say what they will be for
the jet, although for someone to be on his third motor is not an
encouraging sign.

Iâ?Tm certainly very happy with my decision. The range is okay, as an
early
adopter I donâ?Tt have some of the features now available, but it was the
right decision for me at the time. For other people, and in the future,
there may be good reasons for different choices. In my opinion, nobody can
yet know.

Chris N




  #29  
Old September 25th 12, 09:33 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 18
Default Which sustainer system would you chose for your sailplane?

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...gelfliegen.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
  #30  
Old September 26th 12, 09:30 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 18
Default Which sustainer system would you chose for your sailplane?

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



As there was a lot of votes today for JET (I think good article on link above helps) I think I need to lighten some more advantages of FES:

-Light gliders like Silent, AS13.5, Apis becomes with FES real selflaunchers with comparable or even better climb rates than if equiped with combustion retractable engines.

-Even when FES is installed on 18m glider, max climb rate is much better than it is achived with JET or Solo.

-As it is slower than JET you do not pass thermals too quickly, but you can do some turns to center (under power or even without, at normal thermaling speeds) and preserve energy. Actually is it suprising how much energy is even in weak thermals.

-You can use it in mountains, on the ridge to help you climb above the peaks. Even that you have motor you still feel it as soaring, so not bad feling...

-FES is possible to use even in horizontal flight trough (not too heavy) rain (ventlation is prefared to be closed) without fear to damage proppeller blades up to about 3500 RPM.

-Only at FES start is instant, so it can save you out of unladable valleys.

Regards,

Luka
 




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