Auto-Towing - why is this not more popular?

Dan, a pulley tow launches a glider just fine - but then you need to reset for the next launch. Often, this means untangling the rope. Straight auto tow or winch launch rarely tangles the rope.

There are very few pulley tow operations in the world and cycle time is the usual reason why they gave up on pulleys and moved on to winch launch.


On Monday, October 5, 2015 at 9:16:28 AM UTC-6, Dan Marotta wrote:
I once flew for an ESPN video on flying (Secrets of Speed).* One of
the launch methods used was an auto pulley tow wherein the pulley
was mounted to the receiver on the back of the car and the cable was
staked to the ground near mid field.* The car drove in the takeoff
direction during the launch and, with the 2:1 advantage of the
pulley, it was every bit as exciting as a winch.* The car drove at
about 1/2 the speed of the glider.* We were using a 3,400' runway
and I don't recall the release height, though it was not as high as
a winch with a full runway length of cable.




On 10/5/2015 5:01 AM, GB wrote:



Good question. Seems to me reverse car tows(fixed pulley windward car drives toward the glider) would be the way to go. Has there been any sailplane work with car mounted pay out winches? Pay out winches are what the hangglider and paraglider community have mostly settled on using. Both of these solutions somewhat mitigate the space needed to auto tow.






--

Dan, 5J

On Monday, October 5, 2015 at 5:59:07 PM UTC-6, WB wrote:

I'm an enthusiastic advocate of ground launching, however, at least in the U.S., tow planes provide operational flexibility that winches and auto launch do not. Towplanes can operate out of fields that are too short/narrow for ground launch operations (getting your winch line out of trees is no fun). Try to take a winch somewhere besides the home field. It can be anything but straightforward to insure a winch for transport and operation anywhere but your home field. Getting permission for ground launching at a different field can be difficult (someone else mentioned in another thread about the lost opportunity to have glider operations to ever be accepted as normal in the U.S.). Not to mention being able to choose a launch height, aero retrieve/transport of gliders, contest towing, etc.

We do need more ground launching in the U.S., but most of our clubs and commercial ops cannot afford time and/or money to do both aerotow and ground launch other than as an occasional exercise.

All of these objections to winch launch have been put to rest. If you want to see small field winch operations, use Google Earth to look at European, particularly German, glider airports. Many are as short as 1000m and surrounded by trees. Just pick club names from OLC and enter them in the GE search field.

Winch launch will never drop the rope anywhere except right in front of the winch unless the rope breaks which is getting very rare with ultra-strong ropes.

If a pilot really thinks a distant tow is necessary, then use a sustainer from a winch launch.

SSA group insurance offers winch coverage for traveling to and operating at any airfield.

From the guy who ran the Cadilac auto-tow camp last year...

"Auto-tow pointers" - Cadillac, MI camp

Gliders: ASW12, ASK21, ASW15, RS15, and some others
Tow vehicle: Late model Ford Fairmont, V8, 305 cubic inch
Tow rope: Initially, dacron 1500 ft The next year spectra 1500ft
Runway length 5200 ft (field elevation - 800 msl)
Average altitude gain 1000 to 1200 ft (occasionally 1500ft)
Get away rate for cross country: 75%

Highlights:
Six pilots auto-tow launch endorsed in one day and a 12-year annual (Thank you Stan & Carol)
Over 100 hours of XC in the 12 from auto-tow in 1 yr

Lowlights: introduced to a club with many solo pilots, not many tow pilots, and left the unit with them for a year. They never used it!

Auto-Tow unit description: 1500 ft.rope on a reel powered by a Ford starter motor 1950's vintage (exposed shaft beyond motor housing) controlled by a dead man type switch. Reel in time about 1 minute. Easily fits in trunk. The emergency release mechanism is a larger copy of Schweizer tow release mounted to a hitch with a rope to the driver. The driver has radio communication to glider. The driver is any person that is willing. The driver is instructed to accelerate smoothly until glider lifts off and then add 5mph unless told otherwise. Normally, this meant (after glider lift off) full to the floorboard (and to remember that the runway does have an end!).

Note: the glider has a window that, if looked out of, shows the whole operation. So remind the driver as you see her, or him nearing the end.

For those of you that think this technique is not proper well, ok. For those that are willing, this is a way to launch sailplane with: 1) less cost and 2) no need for a tow pilot or tow aircraft. This auto-towing technique is ideal for any "club" with a willing group of two or more. Oh yes, the safety checks were performed on all gliders used. They all had properly functioning, carefully inspected tow releases.

sidenote - one fine lady got to boast that she jerked three guys off and kept them all up at the same time

Sean (still shaking my head at the sidenote).
7T

On Monday, October 5, 2015 at 6:18:15 PM UTC-6,
http://www.coloradosoaring.org/think...ey/default.htm

Reverse pulley is the best way to autotow. Cotswold no longer does this, but did so for about 30 years.

Frank Whiteley

wrote:
Dan, a pulley tow launches a glider just fine - but then you need to reset for the next launch. Often, this means untangling the rope. Straight auto tow or winch launch rarely tangles the rope.

There are very few pulley tow operations in the world and cycle time is the usual reason why they gave up on pulleys and moved on to winch launch.


On Monday, October 5, 2015 at 9:16:28 AM UTC-6, Dan Marotta wrote:
I once flew for an ESPN video on flying (Secrets of Speed).* One of
the launch methods used was an auto pulley tow wherein the pulley
was mounted to the receiver on the back of the car and the cable was
staked to the ground near mid field.* The car drove in the takeoff
direction during the launch and, with the 2:1 advantage of the
pulley, it was every bit as exciting as a winch.* The car drove at
about 1/2 the speed of the glider.* We were using a 3,400' runway
and I don't recall the release height, though it was not as high as
a winch with a full runway length of cable.




On 10/5/2015 5:01 AM, GB wrote:



Good question. Seems to me reverse car tows(fixed pulley windward car drives toward the glider) would be the way to go. Has there been any sailplane work with car mounted pay out winches? Pay out winches are what the hangglider and paraglider community have mostly settled on using. Both of these solutions somewhat mitigate the space needed to auto tow.






--

Dan, 5J

On Monday, October 5, 2015 at 7:32:02 PM UTC-6, Sean Fidler wrote:
From the guy who ran the Cadilac auto-tow camp last year...

"Auto-tow pointers" - Cadillac, MI camp

Gliders: ASW12, ASK21, ASW15, RS15, and some others
Tow vehicle: Late model Ford Fairmont, V8, 305 cubic inch
Tow rope: Initially, dacron 1500 ft The next year spectra 1500ft
Runway length 5200 ft (field elevation - 800 msl)
Average altitude gain 1000 to 1200 ft (occasionally 1500ft)
Get away rate for cross country: 75%

Highlights:
Six pilots auto-tow launch endorsed in one day and a 12-year annual (Thank you Stan & Carol)
Over 100 hours of XC in the 12 from auto-tow in 1 yr

Lowlights: introduced to a club with many solo pilots, not many tow pilots, and left the unit with them for a year. They never used it!

Auto-Tow unit description: 1500 ft.rope on a reel powered by a Ford starter motor 1950's vintage (exposed shaft beyond motor housing) controlled by a dead man type switch. Reel in time about 1 minute. Easily fits in trunk. The emergency release mechanism is a larger copy of Schweizer tow release mounted to a hitch with a rope to the driver. The driver has radio communication to glider. The driver is any person that is willing. The driver is instructed to accelerate smoothly until glider lifts off and then add 5mph unless told otherwise. Normally, this meant (after glider lift off) full to the floorboard (and to remember that the runway does have an end!).

Note: the glider has a window that, if looked out of, shows the whole operation. So remind the driver as you see her, or him nearing the end.

For those of you that think this technique is not proper well, ok. For those that are willing, this is a way to launch sailplane with: 1) less cost and 2) no need for a tow pilot or tow aircraft. This auto-towing technique is ideal for any "club" with a willing group of two or more. Oh yes, the safety checks were performed on all gliders used. They all had properly functioning, carefully inspected tow releases.

sidenote - one fine lady got to boast that she jerked three guys off and kept them all up at the same time

Sean (still shaking my head at the sidenote).
7T

The former Enstone GC in the UK used autotow for several years. Parafil was used as it could be dragged along the tarmac without appreciable wear. Parafil is not pulley friendly (they tried). It was easily spliced.
Case study, http://linearcomposites.net/media/pa...e_study_13.pdf

The club moved on to winches before we wore out the parafil. 1500ft plus launches were done on a 500m length using an XJ-6 Jaguar with 275hp. We just pulled it back to the launch point at 65mph. Near tangled though we did snag a couple of things in the tall grass on the north side of the runway.

That engine replaced the 150hp Bedford diesel in one of the ex-ATC winches. Another winch was refitted with the motor and transmission from a stolen Rolls Royce that was burned on the airfield one night.

I don't think the third ex-ATC winch was ever put into service before the club folded.

Maybe some lurker knows the fate of those winches.

Frank Whiteley

Aéroclub; Vol à Voile Montagne Noire
Airflield; LFMG


http://www.hostingpics.net/viewer.ph...945686251o.jpg

The former Enstone GC in the UK used autotow for several years.
Parafil
wa=
s used as it could be dragged along the tarmac without
appreciable wear.
P=
arafil is not pulley friendly (they tried). It was easily spliced.
Case study,
http://linearcomposites.net/media/pa...e_study_13.pdf

The club moved on to winches before we wore out the parafil.
1500ft plus
l=
aunches were done on a 500m length using an XJ-6 Jaguar with
275hp. We
jus=
t pulled it back to the launch point at 65mph. Near tangled
though we did
=
snag a couple of things in the tall grass on the north side of the
runway.

That engine replaced the 150hp Bedford diesel in one of the ex-
ATC
winches.=
Another winch was refitted with the motor and transmission from
a stolen
=
Rolls Royce that was burned on the airfield one night.

I don't think the third ex-ATC winch was ever put into service
before the
c=
lub folded.

Maybe some lurker knows the fate of those winches.

Frank Whiteley

I learned to fly at Enstone in the late 70s but my recollections of
parafil are very different. Once the outer sheath had been worn
through on retrieves the cable broke on about 1 in 5 launches.
Since we were using scrapper cars we mounted the cable
attatchment in the middle of the roof. This solved the problem of
lifting the weight off the rear wheels when towing.
We also built a special which used a Ford Transit pickup with a mid
mounted 4.2litre Jaguar engine. We retained the original axle which
gave us very good acceleration but a top speed of about 60mph.

I now fly at Lasham which used to use Autotow. We now use
modern winches which give better and safer launches to 1700-
2000ft on a normal day. The cost of buying, maintaining and
running costs of autotow were much higher than the winch in the
UK. Gasoline about $7.50 a gallon here. Winch runs on LPG.

At 12:43 06 October 2015, Nigel Pocock wrote:

The former Enstone GC in the UK used autotow for several years.
Parafil
wa=
s used as it could be dragged along the tarmac without
appreciable wear.
P=
arafil is not pulley friendly (they tried). It was easily spliced.
Case study,
http://linearcomposites.net/media/pa...e_study_13.pdf

The club moved on to winches before we wore out the parafil.
1500ft plus
l=
aunches were done on a 500m length using an XJ-6 Jaguar with
275hp. We
jus=
t pulled it back to the launch point at 65mph. Near tangled
though we did
=
snag a couple of things in the tall grass on the north side of the
runway.

That engine replaced the 150hp Bedford diesel in one of the ex-
ATC
winches.=
Another winch was refitted with the motor and transmission from
a stolen
=
Rolls Royce that was burned on the airfield one night.

I don't think the third ex-ATC winch was ever put into service
before the
c=
lub folded.

Maybe some lurker knows the fate of those winches.

Frank Whiteley

I learned to fly at Enstone in the late 70s but my recollections of
parafil are very different. Once the outer sheath had been worn
through on retrieves the cable broke on about 1 in 5 launches.
Since we were using scrapper cars we mounted the cable
attatchment in the middle of the roof. This solved the problem of
lifting the weight off the rear wheels when towing.
We also built a special which used a Ford Transit pickup with a mid
mounted 4.2litre Jaguar engine. We retained the original axle which
gave us very good acceleration but a top speed of about 60mph.

I now fly at Lasham which used to use Autotow. We now use
modern winches which give better and safer launches to 1700-
2000ft on a normal day. The cost of buying, maintaining and
running costs of autotow were much higher than the winch in the
UK. Gasoline about $7.50 a gallon here. Winch runs on LPG.

For info.
The RR engine powered winch is at north wales gliding club, we are
putting it back in service as our chevy powered winch destroyed its
gearbox last sunday with wave all over the site so the pw6 pilot the only
launch of the day managed to get a nice wave flight, so the RR will get
another lease of life starting this week end with a bit of luck.
KF.

I've had a lot of fun Auto Towing at Sunflower in the last few years. Twice when I've had family visiting, we've taken them up in the 2-33 on Auto Tow, with Leah driving and me flying. Everyone gets involved in the operation, everyone has fun, and it's cheap.

We have a lot of room. We usually start the launch from wherever the glider stopped on landing, usually with around 6000 feet remaining. Usually we use a 2000 foot-ish long rope. Usually we get our 2-33 to around 1000 feet AGL without much extra effort. We could accelerate faster, we could pull harder, and we would have more rope breaks and more wear and tear on the car and the glider. There is a lot of extra wear and tear on everything involved, whether winch launching or auto towing, to get that last 10% of altitude.

When I was giving my grandparents rides and my little sister her first flying lessons on Labor Day, we had a great wind gradient and our best launch in the 2-33 was 1500 AGL. This is on the "nose" aerotow hook.

One of our club members has built a few pulleys but we haven't had a chance to test them out. I am kind of more interested in a 3:1 reduction with a moving and fixed pulley. This allows the towing car to also have a tow release in case the glider can't release. Also reduces the car speed, increases acceleration, and allows you to use less runway.

We've almost exclusively been auto towing the last few years with my 3.6L 2014 Subaru Outback with a homemade schweizer-like tow release in the receiver hitch.

I'd like to get a hitch mounted rope rewinder along with the tow release. Then I think that with a parachute on the glider end we could wind the rope in before the end hit the ground, greatly reducing our wear and tear and not hurting the turn around time much.

Sometimes when I'm dreaming I think that a mobile glider school with an auto tow rig and a two seater on a trailer could be fun. There are a lot of people out there who are interested in flying gliders but just don't live within a convenient distance to a club or commercial operation.

After reading about Casey Aviation's Auto Towing (http://flycasey.com/auto-towing-a-glider/) we got some of the flat pull tape that he was talking about. It is cheap, available in long lengths, and plenty strong enough. Unfortunately it just didn't last at all on our rough old runway and its almost impossible to splice. At least it wasn't an expensive experiment.

At 04:29 06 October 2015, Frank Whiteley wrote:
On Monday, October 5, 2015 at 7:32:02 PM UTC-6, Sean Fidler wrote:
From the guy who ran the Cadilac auto-tow camp last year...
=20
"Auto-tow pointers" - Cadillac, MI camp
=20
Gliders: ASW12, ASK21, ASW15, RS15, and some others =20
Tow vehicle: Late model Ford Fairmont, V8, 305 cubic inch=20
Tow rope: Initially, dacron 1500 ft The next year spectra 1500ft
Runway length 5200 ft (field elevation - 800 msl)
Average altitude gain 1000 to 1200 ft (occasionally 1500ft)=20
Get away rate for cross country: 75%
=20
Highlights: =20
Six pilots auto-tow launch endorsed in one day and a 12-year annual
(Than=
k you Stan & Carol)
Over 100 hours of XC in the 12 from auto-tow in 1 yr=20
=20
Lowlights: introduced to a club with many solo pilots, not many tow
pilo=
ts, and left the unit with them for a year. They never used it!
=20
Auto-Tow unit description: 1500 ft.rope on a reel powered by a Ford
star=
ter motor 1950's vintage (exposed shaft beyond motor housing)
controlled
by=
a dead man type switch. Reel in time about 1 minute. Easily fits in
trun=
k. The emergency release mechanism is a larger copy of Schweizer tow
relea=
se mounted to a hitch with a rope to the driver. The driver has radio
comm=
unication to glider. The driver is any person that is willing. The
driver=
is instructed to accelerate smoothly until glider lifts off and then add
5=
mph unless told otherwise. Normally, this meant (after glider lift off)
fu=
ll to the floorboard (and to remember that the runway does have an
end!). =
=20
=20
=20
=20
For those of you that think this technique is not proper well, ok. For
t=
hose that are willing, this is a way to launch sailplane with: 1) less
cost=
and 2) no need for a tow pilot or tow aircraft. This auto-towing
techniqu=
e is ideal for any "club" with a willing group of two or more. Oh yes,
the=
safety checks were performed on all gliders used. They all had properly
f=
unctioning, carefully inspected tow releases. =20
=20

=20
Sean (still shaking my head at the sidenote).
7T

The former Enstone GC in the UK used autotow for several years. Parafil
wa=
s used as it could be dragged along the tarmac without appreciable
wear.
P=
arafil is not pulley friendly (they tried). It was easily spliced.
Case study,
http://linearcomposites.net/media/pa...e_study_13.pdf

The club moved on to winches before we wore out the parafil. 1500ft
plus
l=
aunches were done on a 500m length using an XJ-6 Jaguar with 275hp.
We
jus=
t pulled it back to the launch point at 65mph. Near tangled though we
did
=
snag a couple of things in the tall grass on the north side of the
runway.

That engine replaced the 150hp Bedford diesel in one of the ex-ATC
winches.=
Another winch was refitted with the motor and transmission from a
stolen
=
Rolls Royce that was burned on the airfield one night.

I don't think the third ex-ATC winch was ever put into service before the
c=
lub folded.

Maybe some lurker knows the fate of those winches.

Frank Whiteley


For info
The winch with RR engine is at north wales gliding club,
our other winch destroyed it,s gearbox on sunday so the Rolls Royce is to
be put back to work this weekend with some luck.
KF