Mini-Winch for FES

How about taking the running gear from a salvaged Tesla or similar? A
quick look found several in the $10K range and I'm sure you could find
something for less.Â* Also, simple research (looking at one website) says
that the Tesla's battery provides around 400 VDC which is fed to an
inverter to provide the AC voltage to run the motor(s).Â* Surely someone
could put together a battery bank (assuming the car's batteries are not
functional) or even have a 480 V 3-phase service installed to run the
motors.

Now, we just need someone to build the hardware to connect the motor(s)
to the drum.

Or buy a ready-made winch.

On 3/4/2020 12:21 PM, ian wrote:
On 3/4/20 7:38 AM, Paul Remde wrote:

Any thoughts...?Â* I'm just dreaming about the future of gliding...

Speaking as a winch instructor. One requirement for a safe winch
launch is for the glider to always be in a position to make a safe
landing in the event of a launch failure. Thus the launch profile must
be such that by the time that you are too high to land straight ahead
you have sufficient height to fly a small circuit and land back on the
runway. You also want some overlap between the two options to take the
stress out of decision making. If you winching into zero or low winds,
a 180 deg turn and landing "downwind" is also an option.

If you are winch launching a sustainer, the requirement must be for
the glider to launch, release, attempt an engine start and then still
be in a position to make a safe landing if the engine fails.

What you do not want, is to make a habit of releasing over the
downwind threshold, to low to fly a circuit back over the runway. (Yes
this is accepted for aerotow. But the launch failure rate is much
lower and simulated launch failure training is done in light winds
which allow landing downwind.)

One option is a conventional ground launch, car or winch to say 1000'
AGL. Glider can then fly a circuit, start the engine on downwind and
be in a position to land if the engine does not start. This would work
for any sustainer technology. The ground launch is an "existing art"
and you can get training and ratings for it. There are also
established clubs with the means to provide the launch.

Next option is the "launch to 100'". This must be done such that you
can release, attempt an engine start and still be able to land
straight ahead if it fails. A variation involves deploying and even
starting the engine before launch, with a pylon mounted engine, like a
jet, but not possible with FES. This saves some time for the engine
start and reduces the risk of a start failure. These launches have
been done, but you wont easily find an "approved procedure" accepted
by manufacturers and authorities etc.

Last comment, is do not assume that FES cannot suffer a launch
failure. They have safety control systems and all it would take is one
contact breaker "trip" to spoil your day. Also remember that any
battery energy you use to get from 100' to "start of soaring" will not
be available for a retrieve later in the day.

But yes, this could be the future of gliding ...

Ian

--
Dan, 5J

On Wednesday, March 4, 2020 at 2:39:29 PM UTC-5, Dan Marotta wrote:
How about taking the running gear from a salvaged Tesla or similar? A
quick look found several in the $10K range and I'm sure you could find
something for less.Â* Also, simple research (looking at one website) says
that the Tesla's battery provides around 400 VDC which is fed to an
inverter to provide the AC voltage to run the motor(s).Â* Surely someone
could put together a battery bank (assuming the car's batteries are not
functional) or even have a 480 V 3-phase service installed to run the
motors.

Now, we just need someone to build the hardware to connect the motor(s)
to the drum.

Or buy a ready-made winch.

On 3/4/2020 12:21 PM, ian wrote:
On 3/4/20 7:38 AM, Paul Remde wrote:

Any thoughts...?Â* I'm just dreaming about the future of gliding....

Speaking as a winch instructor. One requirement for a safe winch
launch is for the glider to always be in a position to make a safe
landing in the event of a launch failure. Thus the launch profile must
be such that by the time that you are too high to land straight ahead
you have sufficient height to fly a small circuit and land back on the
runway. You also want some overlap between the two options to take the
stress out of decision making. If you winching into zero or low winds,
a 180 deg turn and landing "downwind" is also an option.

If you are winch launching a sustainer, the requirement must be for
the glider to launch, release, attempt an engine start and then still
be in a position to make a safe landing if the engine fails.

What you do not want, is to make a habit of releasing over the
downwind threshold, to low to fly a circuit back over the runway. (Yes
this is accepted for aerotow. But the launch failure rate is much
lower and simulated launch failure training is done in light winds
which allow landing downwind.)

One option is a conventional ground launch, car or winch to say 1000'
AGL. Glider can then fly a circuit, start the engine on downwind and
be in a position to land if the engine does not start. This would work
for any sustainer technology. The ground launch is an "existing art"
and you can get training and ratings for it. There are also
established clubs with the means to provide the launch.

Next option is the "launch to 100'". This must be done such that you
can release, attempt an engine start and still be able to land
straight ahead if it fails. A variation involves deploying and even
starting the engine before launch, with a pylon mounted engine, like a
jet, but not possible with FES. This saves some time for the engine
start and reduces the risk of a start failure. These launches have
been done, but you wont easily find an "approved procedure" accepted
by manufacturers and authorities etc.

Last comment, is do not assume that FES cannot suffer a launch
failure. They have safety control systems and all it would take is one
contact breaker "trip" to spoil your day. Also remember that any
battery energy you use to get from 100' to "start of soaring" will not
be available for a retrieve later in the day.

But yes, this could be the future of gliding ...

Ian

--
Dan, 5J

How hard could it be?
Sigh
UH

On Wednesday, March 4, 2020 at 3:04:34 PM UTC-5, wrote:
How hard could it be?
Sigh
UH

Yep! How hard could it be?
https://www.youtube.com/watch?v=R--m0NDR0j8

I did watch a live demo of a high-performance jet sustainer glider using an auto tow on a short rope (IIRC, a conventional aerotow rope) to get the sailplane moving fast enough to spin up the jet and get off the ground, at which point (less than 100 feet) the pilot released and climbed away, with plenty of room to land straight ahead on the [hard surface] runway if necessary. Pretty impressive. But no interference with an FES prop to worry about.

I also watched an FES ASW 27 self launch a few years ago from a hard surface runway. Also pretty impressive.

Chip Bearden
JB

On one level I think this is an interesting idea. The concept of a low
level launch and climb away on FES is one that I've
heard others raise, but always in relation to aerotow.

The norm in a winch launch is to gently transition to a 45 degree climb in
a way which ensures you can always recover to a safe attitude and
subsequent landing. This transition typically happens at 30' - 100'. In
principle, if there was enough demand, I think it would be possible to
develop a lower powered winch, and a shallower climb to release, but from a
safety perspective, you would need to be able to ensure that if the FES did
not start, you could always land safely. Given the likely release height,
this would need a long enough run to land ahead safely from any failure.
The dynamic would be very site specific.

While any 'lower powered winch' might be slightly cheaper than one which
could launch to higher heights, most of the engineering would be very
similar, and my guess is not much cheaper. The days of low cost, self help
winches have largely gone in Europe, with the reality being that while
these were cheap(ish) to build, they could be quite dangerous. The modern
equivalent are much, much safer to operate (ground operations and flying
wise) but expensive. IIt;s an interse think for most US operations with
limited winch experience, the learning curve for even the most modern kit
would be steep.

Also factor in that most high performance gliders will want to get airborne
fully ballasted. This increases the likelihood of a launch failure, and
might make a safe landing from a failure much more interesting. I have
thousands of winch launches, and train others to recover from failures, but
always choose to fly my ballasted Ventus from aerotow. It's just about the
risk balance.

It's an interesting idea, and is certainly possible in my view, but I don't
really think it's commercially viable option where there is no existing
infrastructure. At our club, with all of the winch launching
infrastructure in place, the small number of FES equipped gliders choose to
go to the top of the winch launch (we would charge the same anyway). Lower
launches would save some fuel, but mixing lower launched with higher ones
would be a pain, and save no time.

Overall, I think a low level aerotow might be a much better option.


While winch launching is very common in Europe,

At 05:38 04 March 2020, Paul Remde wrote:
Hi,

This is just a thought... =20

I=E2=80=99ve recently been extremely interested in the FES (Front
Electric
=
Sustainer) sailplanes. They are becoming quite popular. Even very
high-pe=
rformance racing sailplanes like the Ventus 3 are being sold with FES
syste=
ms installed.

I am the U.S. dealer for DG/LS and they offer the LS8e neo with FES and
the=
new DG-1001e neo with FES prototype will fly very soon. It will be the
fi=
rst 2-seat sailplane with FES. I would love to trade my DG-1000S in for
a
=
DG-1001e neo with FES, but so far my DG-1000S co-owners aren't ready for
th=
at upgrade.

I'm not very experienced with winches and certainly not an expert on such
m=
atters, but I think there may be a nice market for a very small electric
wi=
nch designed to get an FES-equipped sailplane just up to 100 feet
=E2=80=93=
high enough to use the FES to climb to the first thermal. Even
self-launc=
h capable FES sailplanes would benefit from a small winch because they
woul=
d save much more of the sailplane's battery for use later in the flight -
s=
ince the initial takeoff roll requires a lot of power.

You can see an interesting video showing an FES-equipped sailplane taking
a=
n autotow to about 100 feet he=20
https://youtu.be/pTeNKM2cXQk=20

I would think that an electric winch could get a glider to 100 feet quite
e=
asily and be quite small and relatively inexpensive. The rope needed
would=
be much less, and the drum could be much smaller =E2=80=93 I imagine.

A "level ground bungee launch" to 100 feet would be another interesting
opt=
ion. But I would think that would have risks from by the bungee snapping
o=
r coming loose and hurting someone.=20

Any thoughts...? I'm just dreaming about the future of gliding...

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

I'd rather take my chances on something that would accelerate the glider 0-50 knots in 50 meters with the FES running from the very start of the roll. This would increase available runway ahead for launch failure and conserve a bit of battery power. Fully automated with pilot pushing the go button..

How much runway do you need to self-launch a heavy two place FES when there is sink and windshear present?

I'd rather take my chances on something that would accelerate the glider 0-50 knots in 50 meters with the FES running from the very start of the roll. This would increase available runway ahead for launch failure and conserve a bit of battery power. Fully automated with pilot pushing the go button.

You just need to an old aircraft carrier catapult!

Have you ever seen an FES propeller extended?Â* There's no way I'd
attempt a launch either by air, auto, or winch with that prop spinning!Â*
Now, a catapult launch might just work and it might just rip the landing
gear off the ship.

I wonder if Mark would post that video of the solar electric prototype
glider model catapult test launch.Â* Hint:Â* The fuselage flew a short
distance but the wings remained at the takeoff point.

On 3/4/2020 11:22 PM, son_of_flubber wrote:
I'd rather take my chances on something that would accelerate the glider 0-50 knots in 50 meters with the FES running from the very start of the roll. This would increase available runway ahead for launch failure and conserve a bit of battery power. Fully automated with pilot pushing the go button.

How much runway do you need to self-launch a heavy two place FES when there is sink and windshear present?


--
Dan, 5J

Well with the right hill and some head wind...
https://youtu.be/zdCGb9-vjck

Bungees?Â* We don't need no stinking bungees!
https://www.youtube.com/watch?v=lbRAqPxd49E

On 3/5/2020 8:47 AM, Mike N. wrote:
Well with the right hill and some head wind...
https://youtu.be/zdCGb9-vjck

--
Dan, 5J