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)

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

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

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

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

For me electrical sustainer in a glider is the perfect solution. It links in to the spirit of the sport, beter than a turbine. But the propellor on the nose feels slightly off.... Especially when you consider the bugwipergarages becoming standard on the topsailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pilon whit this nice foldable propellor you have engineered? Or am I the only one who has this uncomfortable feeling?

Secondly adding 45 kg to the non- lifting parts is a bit of a stretch. I contacted a manufacturer who was very kind to talk more than 30 minutes on the subject. But changing this limit on existing planes seems very far fetched. Any news in this area?

Marco

On Sep 26, 6:06*pm, wrote:
For me electrical sustainer in a glider is the perfect solution. It links in to the spirit of the sport, beter than a turbine. But the propellor on the nose feels slightly off.... Especially when you consider the bugwipergarages becoming standard on the topsailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pilon whit this nice foldable propellor you have engineered? Or am I the only one who has this uncomfortable feeling?

Secondly adding 45 kg to the non- lifting parts is a bit of a stretch. I contacted a manufacturer who was very kind to talk more than 30 minutes on the subject. But changing this limit on existing planes seems very far fetched. Any news in this area?

Marco

I also have an issue with modification to the front of the fuselage
where the tow hook is (at least in my glider) and another point is
that this is an important area not to be tempered with in crash
resistant cockpits. I have no problems with the added weight due to my
good eating habits .

On Thursday, 27 September 2012 00:06:31 UTC+2, wrote:
For me electrical sustainer in a glider is the perfect solution. It links in to the spirit of the sport, beter than a turbine. But the propellor on the nose feels slightly off.... Especially when you consider the bugwipergarages becoming standard on the topsailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pilon whit this nice foldable propellor you have engineered? Or am I the only one who has this uncomfortable feeling?

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open 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 associated with pylon mounted systems.

If I had the money for a self launcher or sustainer equipped glider it would 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 things that operate at high temperatures and need to be maintained regularly. A brushless electric motor can literally run for years with a decent set of bearings. That means less hassle and maybe lower maintenance costs over the long run depending on the battery technology being used.

A sustainer option would suite me perfectly. I don't need to operate autonomously and a winch launch to 1500 feet is cheap ($4.70 USD) and preserves power for when I may need it.

On Friday, January 8, 2016 at 1:40:33 AM UTC-5, Surge wrote:
On Thursday, 27 September 2012 00:06:31 UTC+2, wrote:
For me electrical sustainer in a glider is the perfect solution. It links 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 bugwiper garages becoming standard on the top sailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pylon with this nice foldable propeller you have engineered? Or am I the only one who has this uncomfortable feeling?

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open 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 associated with pylon mounted systems.

If I had the money for a self launcher or sustainer equipped glider it would 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 things that operate at high temperatures and need to be maintained regularly. A brushless electric motor can literally run for years with a decent set of bearings. That means less hassle and maybe lower maintenance costs over the long run depending on the battery technology being used.

A sustainer option would suite me perfectly. I don't need to operate autonomously 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 sized EDF. Unless of course, you want to make the fuselage larger, but that add's wetted area and reduces the performance.

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