Mini-Winch for FES

On 3/4/20 7:38 AM, Paul Remde wrote:

Any thoughts...? 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

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 Friday, March 6, 2020 at 4:20:40 PM UTC-8, wrote:
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

Chip,

I talked to a JS pilot at Little Rock that does that regularly. He and his wife have it pretty well dialed in.

As I understood the initial discussions, I didn't hear anyone proposing launching with FES running. They would just use the belly hook on the aircraft for the initial launch and then start the FES. Not a bad option if you have enough runway to leave options.

Waiting for spring...

Craig Funston
JN