Auto-Towing - why is this not more popular?

On Monday, February 1, 2016 at 11:38:29 PM UTC-6, wrote:
7T......Reading your October post on Auto Tow. But first gotta tell you I have LS-1f N57T. Contest number original to Rudy Moser was 7T when I bought it in 1984.
Concerning auto tow, I used to do it quite a bit. Having learned to fly on the winch in a 2-22 at Black Forest in 1965, I found auto towing pretty much the same. The system which We all liked best was to use a pulley. Glider accelleration is so fast that two people, pilot and driver sufficed. The late Mike Evans and I used to fly together at Westcliffe, Colorado all the time. Using wing stands only we never needed a wing runner, and never ever had any problems. Radio is essential between pilot and driver. We could fine tune airspeed by voice communication. If you need 10 more knots at the glider, remember to ask only for five. The glider is traveling at twice the car speed. The reason we used the pulley was so we could tow with my manual stick Toyota Land Cruiser. With the pulley we did the entire tow in 2nd gear and did not need to shift. Shifting would have put a big strain on the car, and we were afraid it would have induced a big interuption of speed. To pulley tow with a single pulley you need a long runway and a lot of rope. We had a 4300' 3/8 poly rope with weak links at each end. We routinely saw tows ranging from 1700 to 1900 feet. At Westcliffe I cannot think of a many times that any of us had to relight. During winter the primary wave of the Sangre de Cristo Mountains is overhead and believe it or not we used to often find strong wave lift as low as 400 and 500 feet agl. Unless I had enciuntered it often and someone told me I would not believe it. But it's true. During summer thermals were plentiful and a 1700 foot tow worked fine. I did straight auto tows later when living at Pinedale Wyoming. I had a 2500 foot rope and 1600 feet agl was pretty standard. If you are going for quantity of flights then aerotow is probably faster. Repositioning the rope eats up time. I always had a parachute on the end of the rope with a 15 foot leader from the apex of the chute to the glider. That way the rope layed out straight. If after the glider has released from a pulley tow, and there is runway remaining the car can continue which pulls the rope and parachute closer to the pulley with a straight rope as the parachute lands. athis saves lots of retrieval time. C.G. hooks work best for ground launch. Nose hooks with too much back pressure at the top of the launch will cause the glider to porpoise. Releasing some back pressure remedies that. If you can get endorsed by an instructor with experience, I highly recommend ground launching. The runways we used were 6000 feet long. The setup we used to pulley tow was to attach the end of the rop to another car parked well off to the side of the runway, then loop the rope through the snatch block pulley securely tied to the tow hitch on the tow car. We tied it because it needs to be flexable. Then we pulled away from the glider. In order to tow towards the glider as in the case of a short runway, you need a second pulley to reverse direction. The pulley or pulleys need to be high quality with ball bearings and grease fittings. Mine have always been about 6 inch diameter. Also dont use nylon rope. Too much stretch. After liftoff on the pulley tow expect some bowing or slack as there is some sling shot effect as the stretch comes out of the rope. It only lasts a couple seconds so do not rotate into a steeper attitude until the rope is tight again.

Mike,

We've started doing a little pulley experimenting in the same manner you describe. Our biggest mistake was in starting out using a low quality pulley. We had a lawn mower front wheel rim, with a greased bushing. The first day of launching we did it worked OK but once it starts to lose grease it gets hot quick. On our second day of launching with it it overheated and seized.. So now we will upgrade, likely to a trailer spindle and rim, which is actually designed for the kinds of loads and speeds that we subject it to on a pulley launch.

Launching our 2-22 and 2-33 with the pulley we were getting about 1500 feet high launches. 4000 feet of rope and 7000 foot runway, without very aggressive technique. Great fun!

On Tuesday, February 2, 2016 at 8:48:46 AM UTC-6, Tony wrote:
On Monday, February 1, 2016 at 11:38:29 PM UTC-6, wrote:
7T......Reading your October post on Auto Tow. But first gotta tell you I have LS-1f N57T. Contest number original to Rudy Moser was 7T when I bought it in 1984.
Concerning auto tow, I used to do it quite a bit. Having learned to fly on the winch in a 2-22 at Black Forest in 1965, I found auto towing pretty much the same. The system which We all liked best was to use a pulley. Glider accelleration is so fast that two people, pilot and driver sufficed. The late Mike Evans and I used to fly together at Westcliffe, Colorado all the time. Using wing stands only we never needed a wing runner, and never ever had any problems. Radio is essential between pilot and driver. We could fine tune airspeed by voice communication. If you need 10 more knots at the glider, remember to ask only for five. The glider is traveling at twice the car speed. The reason we used the pulley was so we could tow with my manual stick Toyota Land Cruiser. With the pulley we did the entire tow in 2nd gear and did not need to shift. Shifting would have put a big strain on the car, and we were afraid it would have induced a big interuption of speed. To pulley tow with a single pulley you need a long runway and a lot of rope. We had a 4300' 3/8 poly rope with weak links at each end. We routinely saw tows ranging from 1700 to 1900 feet. At Westcliffe I cannot think of a many times that any of us had to relight. During winter the primary wave of the Sangre de Cristo Mountains is overhead and believe it or not we used to often find strong wave lift as low as 400 and 500 feet agl. Unless I had enciuntered it often and someone told me I would not believe it. But it's true. During summer thermals were plentiful and a 1700 foot tow worked fine. I did straight auto tows later when living at Pinedale Wyoming. I had a 2500 foot rope and 1600 feet agl was pretty standard. If you are going for quantity of flights then aerotow is probably faster. Repositioning the rope eats up time. I always had a parachute on the end of the rope with a 15 foot leader from the apex of the chute to the glider. That way the rope layed out straight. If after the glider has released from a pulley tow, and there is runway remaining the car can continue which pulls the rope and parachute closer to the pulley with a straight rope as the parachute lands. athis saves lots of retrieval time. C.G. hooks work best for ground launch. Nose hooks with too much back pressure at the top of the launch will cause the glider to porpoise. Releasing some back pressure remedies that. If you can get endorsed by an instructor with experience, I highly recommend ground launching. The runways we used were 6000 feet long. The setup we used to pulley tow was to attach the end of the rop to another car parked well off to the side of the runway, then loop the rope through the snatch block pulley securely tied to the tow hitch on the tow car. We tied it because it needs to be flexable. Then we pulled away from the glider. In order to tow towards the glider as in the case of a short runway, you need a second pulley to reverse direction. The pulley or pulleys need to be high quality with ball bearings and grease fittings. Mine have always been about 6 inch diameter. Also dont use nylon rope. Too much stretch. After liftoff on the pulley tow expect some bowing or slack as there is some sling shot effect as the stretch comes out of the rope. It only lasts a couple seconds so do not rotate into a steeper attitude until the rope is tight again.

Mike,

We've started doing a little pulley experimenting in the same manner you describe. Our biggest mistake was in starting out using a low quality pulley. We had a lawn mower front wheel rim, with a greased bushing. The first day of launching we did it worked OK but once it starts to lose grease it gets hot quick. On our second day of launching with it it overheated and seized. So now we will upgrade, likely to a trailer spindle and rim, which is actually designed for the kinds of loads and speeds that we subject it to on a pulley launch.

Launching our 2-22 and 2-33 with the pulley we were getting about 1500 feet high launches. 4000 feet of rope and 7000 foot runway, without very aggressive technique. Great fun!

Tony and Mike, I'd be interested to know what the turn-around time is (was) between tows. How do you collect and retrieve the mess of tow-line and take it back to the take-off site without spending much time? There's a good reason why winches spool the entire length of wire or Spectra on the drum after glider release.
Herb

On Tuesday, February 2, 2016 at 9:45:28 AM UTC-6, wrote:
On Tuesday, February 2, 2016 at 8:48:46 AM UTC-6, Tony wrote:
On Monday, February 1, 2016 at 11:38:29 PM UTC-6, wrote:
7T......Reading your October post on Auto Tow. But first gotta tell you I have LS-1f N57T. Contest number original to Rudy Moser was 7T when I bought it in 1984.
Concerning auto tow, I used to do it quite a bit. Having learned to fly on the winch in a 2-22 at Black Forest in 1965, I found auto towing pretty much the same. The system which We all liked best was to use a pulley. Glider accelleration is so fast that two people, pilot and driver sufficed. The late Mike Evans and I used to fly together at Westcliffe, Colorado all the time. Using wing stands only we never needed a wing runner, and never ever had any problems. Radio is essential between pilot and driver. We could fine tune airspeed by voice communication. If you need 10 more knots at the glider, remember to ask only for five. The glider is traveling at twice the car speed. The reason we used the pulley was so we could tow with my manual stick Toyota Land Cruiser. With the pulley we did the entire tow in 2nd gear and did not need to shift. Shifting would have put a big strain on the car, and we were afraid it would have induced a big interuption of speed. To pulley tow with a single pulley you need a long runway and a lot of rope. We had a 4300' 3/8 poly rope with weak links at each end.. We routinely saw tows ranging from 1700 to 1900 feet. At Westcliffe I cannot think of a many times that any of us had to relight. During winter the primary wave of the Sangre de Cristo Mountains is overhead and believe it or not we used to often find strong wave lift as low as 400 and 500 feet agl. Unless I had enciuntered it often and someone told me I would not believe it. But it's true. During summer thermals were plentiful and a 1700 foot tow worked fine. I did straight auto tows later when living at Pinedale Wyoming. I had a 2500 foot rope and 1600 feet agl was pretty standard. If you are going for quantity of flights then aerotow is probably faster. Repositioning the rope eats up time. I always had a parachute on the end of the rope with a 15 foot leader from the apex of the chute to the glider. That way the rope layed out straight. If after the glider has released from a pulley tow, and there is runway remaining the car can continue which pulls the rope and parachute closer to the pulley with a straight rope as the parachute lands. athis saves lots of retrieval time. C.G. hooks work best for ground launch. Nose hooks with too much back pressure at the top of the launch will cause the glider to porpoise. Releasing some back pressure remedies that. If you can get endorsed by an instructor with experience, I highly recommend ground launching. The runways we used were 6000 feet long. The setup we used to pulley tow was to attach the end of the rop to another car parked well off to the side of the runway, then loop the rope through the snatch block pulley securely tied to the tow hitch on the tow car.. We tied it because it needs to be flexable. Then we pulled away from the glider. In order to tow towards the glider as in the case of a short runway, you need a second pulley to reverse direction. The pulley or pulleys need to be high quality with ball bearings and grease fittings. Mine have always been about 6 inch diameter. Also dont use nylon rope. Too much stretch. After liftoff on the pulley tow expect some bowing or slack as there is some sling shot effect as the stretch comes out of the rope. It only lasts a couple seconds so do not rotate into a steeper attitude until the rope is tight again.

Mike,

We've started doing a little pulley experimenting in the same manner you describe. Our biggest mistake was in starting out using a low quality pulley. We had a lawn mower front wheel rim, with a greased bushing. The first day of launching we did it worked OK but once it starts to lose grease it gets hot quick. On our second day of launching with it it overheated and seized. So now we will upgrade, likely to a trailer spindle and rim, which is actually designed for the kinds of loads and speeds that we subject it to on a pulley launch.

Launching our 2-22 and 2-33 with the pulley we were getting about 1500 feet high launches. 4000 feet of rope and 7000 foot runway, without very aggressive technique. Great fun!

Tony and Mike, I'd be interested to know what the turn-around time is (was) between tows. How do you collect and retrieve the mess of tow-line and take it back to the take-off site without spending much time? There's a good reason why winches spool the entire length of wire or Spectra on the drum after glider release.
Herb

Herb,

For Pulley launches here is what we did: Glider Releases, car stops, car removes pulley and therefore removes rope from the car. Glider drops rope on the runway or very near. Car drives to anchor vehicle, which releases its end of the rope, grabs that end of the rope and drives to the launch point. Now the rope is laid out nice and straight on the runway. reattach the previous glider end of the rope to the anchor vehicle and thread the rope back through the pulley. Ready for next launch.

For straight auto tows: Glider releases rope to drop on or very near the runway. Car stops, turns around, and drives back to the launch point, then releases its rope. Rope is now laid out straight, no slack, and ready for next launch.

For straight auto tows the car usually meets the glider right after landing.. Add the time it takes to brief the next flight or swap out pilots and there is essentially no delay. Turning around the pulley takes a few more minutes but the launch height is a little higher so that buys some time.

We have a wide runway (200 feet) with no lights and usually empty fields adjacent, so if the rope lands a little wide it's no big deal.

On Tuesday, February 2, 2016 at 5:48:46 PM UTC+3, Tony wrote:
On Monday, February 1, 2016 at 11:38:29 PM UTC-6, wrote:
7T......Reading your October post on Auto Tow. But first gotta tell you I have LS-1f N57T. Contest number original to Rudy Moser was 7T when I bought it in 1984.
Concerning auto tow, I used to do it quite a bit. Having learned to fly on the winch in a 2-22 at Black Forest in 1965, I found auto towing pretty much the same. The system which We all liked best was to use a pulley. Glider accelleration is so fast that two people, pilot and driver sufficed. The late Mike Evans and I used to fly together at Westcliffe, Colorado all the time. Using wing stands only we never needed a wing runner, and never ever had any problems. Radio is essential between pilot and driver. We could fine tune airspeed by voice communication. If you need 10 more knots at the glider, remember to ask only for five. The glider is traveling at twice the car speed. The reason we used the pulley was so we could tow with my manual stick Toyota Land Cruiser. With the pulley we did the entire tow in 2nd gear and did not need to shift. Shifting would have put a big strain on the car, and we were afraid it would have induced a big interuption of speed. To pulley tow with a single pulley you need a long runway and a lot of rope. We had a 4300' 3/8 poly rope with weak links at each end. We routinely saw tows ranging from 1700 to 1900 feet. At Westcliffe I cannot think of a many times that any of us had to relight. During winter the primary wave of the Sangre de Cristo Mountains is overhead and believe it or not we used to often find strong wave lift as low as 400 and 500 feet agl. Unless I had enciuntered it often and someone told me I would not believe it. But it's true. During summer thermals were plentiful and a 1700 foot tow worked fine. I did straight auto tows later when living at Pinedale Wyoming. I had a 2500 foot rope and 1600 feet agl was pretty standard. If you are going for quantity of flights then aerotow is probably faster. Repositioning the rope eats up time. I always had a parachute on the end of the rope with a 15 foot leader from the apex of the chute to the glider. That way the rope layed out straight. If after the glider has released from a pulley tow, and there is runway remaining the car can continue which pulls the rope and parachute closer to the pulley with a straight rope as the parachute lands. athis saves lots of retrieval time. C.G. hooks work best for ground launch. Nose hooks with too much back pressure at the top of the launch will cause the glider to porpoise. Releasing some back pressure remedies that. If you can get endorsed by an instructor with experience, I highly recommend ground launching. The runways we used were 6000 feet long. The setup we used to pulley tow was to attach the end of the rop to another car parked well off to the side of the runway, then loop the rope through the snatch block pulley securely tied to the tow hitch on the tow car. We tied it because it needs to be flexable. Then we pulled away from the glider. In order to tow towards the glider as in the case of a short runway, you need a second pulley to reverse direction. The pulley or pulleys need to be high quality with ball bearings and grease fittings. Mine have always been about 6 inch diameter. Also dont use nylon rope. Too much stretch. After liftoff on the pulley tow expect some bowing or slack as there is some sling shot effect as the stretch comes out of the rope. It only lasts a couple seconds so do not rotate into a steeper attitude until the rope is tight again.

Mike,

We've started doing a little pulley experimenting in the same manner you describe. Our biggest mistake was in starting out using a low quality pulley. We had a lawn mower front wheel rim, with a greased bushing. The first day of launching we did it worked OK but once it starts to lose grease it gets hot quick. On our second day of launching with it it overheated and seized. So now we will upgrade, likely to a trailer spindle and rim, which is actually designed for the kinds of loads and speeds that we subject it to on a pulley launch.

Launching our 2-22 and 2-33 with the pulley we were getting about 1500 feet high launches. 4000 feet of rope and 7000 foot runway, without very aggressive technique. Great fun!

Wait .. how does this work?

The fixed car is next to the middle of the runway (well, 4/7ths down it with 4000 ft rope on a 7000 ft runway), and the moving car starts from adjacent to the fixed car?

On Tuesday, February 2, 2016 at 8:48:46 AM UTC-6, Tony wrote:

Launching our 2-22 and 2-33 with the pulley we were getting about 1500 feet high launches. 4000 feet of rope and 7000 foot runway, without very aggressive technique. Great fun!

And nose hooks. Not the part way back Schwiezer semi-C.G. hook.

Hi Sean,

I attended a Mifflin regional contest years ago. There was a demonstration of an auto launch as an entertainment/instructional affair. One run only because the stress on the hot rodded auto blew the engine. Entertaining but maybe not for the owner of the auto. I think that power generated has to first be transmitted to the wheels, then additional stress on the auto frame. The added load on a changing vector as it transitions from horizontal to vertical has something to do with stress to the auto chassis/engine/traction combination. I've heard from Paul Nicholls that he commanded the auto on one occasion with Dave Nelson and he felt the rear of the auto lifting up loosing traction.

Me thinks that used on a regular basis, the maintenance cost of auto towing would exceed that of a winch.

I do agree that a cost effective alternative to aerotowing such as winching is desirable. This year, flying in the Alps of France, I have changed my base of operation to a winch only airfield. BTW, I have signed up for KS's winch clinic asa refresher.

I learned to fly gliders at a winch only field in a club run mostly by Germans who migrated to Detroit to work in the tool and die shops after the war.. Very economical for a poor student. Six tows, with instruction, and glider rental, was less than twenty dollars. But as in the traditional "old school" European glider clubs, I was made the winch driver and field boy, arriving at 6:00am, setting up the gliders and winch, and driving the winch all day long. I left the field not infrequently at 10:00pm. But I received free instruction from Eb Geyer, a fantastic instructor who taught me many things expecting great discipline. I really mean great discipline. His disciplined instruction saved my butt on several occasions. I owe him a great debt.

What is the cost of a tow plane and the annual maintenance and cost of employing a tow pilot with insurance? You could buy yourself a grand launching machine and have pennies to spare.

On Friday, February 5, 2016 at 5:33:09 AM UTC+3, wrote:
What is the cost of a tow plane and the annual maintenance and cost of employing a tow pilot with insurance? You could buy yourself a grand launching machine and have pennies to spare.

My club in New Zealand has a policy that annual subs pay for admin&clubhouse, glider fees pay for glider maintenance and replacement, and tow fees pay for towplane maintenance and replacement. I think the treasurer does a pretty conservative job on this.

Current tow fees are NZ$15 + $20/1000 ft (up to 3500 ft .. it increases above that). In US$ that's about $10 to start plus $13.33 per 1000 ft.

I think you can reasonably assume that covers the true cost of operating a Pawnee long term.

p.s. we don't pay tow pilots.

That's what they get for hot rodding the engine I guess

My first auto tows were behind an early 90's Dodge Caravan. It had about 300000 miles. Then a few behind Steve Leonard's stalker van also very high mileage. Next up we used my dear Ol Blue V6 GMC pickup. It was in the middle of a not yet diagnosed head gasket failure and simply put running like crap with very low power output. Ol Blue was also north of 300k miles.

Recently we've used my Subaru Outback 3.6L, a relatively new Ford F-150, and a Ford SUV of some sort.

When I lived in Odessa tx we used my GMC pickup truck for auto towing. I don't think the truck even knew the glider (1-26) was there. If you have 5000 feet if paved runway, auto tow is lots of fun. We could get 900 -1000 ft using a 1500 foot rope in a 1-26. We could get away about 1/2 of the time, maybe less. But at 5 bucks a launch, who cares? Plus all those scratching skills have come in handy more than once.

Hello to all!
Please for help: how much is the highest height when towing by a car ("world best achievement")?