Auto-Towing - why is this not more popular?

On Monday, October 5, 2015 at 12:27:24 PM UTC-5, Sean Fidler wrote:
Wow! Great posts. I'll need time to read it all. Thanks.

We have an auto-tow rig in Ionia that has been used on rare occasion. Recently, a clinic was done in Cadillac and it was quite successful from what I understand. A number of people got sign offs, etc. But then it died again.

My honest opinion. Aerotowing is popular because the tow pilot lobby likes flying tow planes for free, building hours, etc. We should be auto-towing more! Especially in early training. It's a safe, viable and great option and if done with great care (as aero and winch are) it could be really impactful to lowering costs and increasing the number of youth pilots being trained.

I think the public would get a kick out of seeing cars towing up gliders at airports! There is just something cool about it!

Anyway...back to work.


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.

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.

On Monday, October 5, 2015 at 1:27:24 PM UTC-4, Sean Fidler wrote:
Anyway...back to work.

Aaarrggg! Stuff like that gives us nightmares Sean...

One reason winch or auto tows are not more popular is that you are released over the airpark. In an aero tow you can be towed to the lift before releasing. Yes, I know usually on soft days there is a thermal just as one turns downwind to base, but that is not the best place to thermal.

IIRC, in the old days a ground launch signoff was required before the commercial glider test. We would do it once a year at the Soaring Society of Dayton (now Caesar Creek Soaring Club) at our Richmond, IN airport, which had 3 paved runways, including two with paved taxiways that we operated off of. 5000-5500'. This was the late 1960s and the age of the big block V-8 horsepower wars so someone always seemed eager to volunteer their vehicle to show it off (probably not a second time, though). We got high enough to do a full pattern in a 2-22. Because it conflicted with our normal ops, we tended to pick an overcast day, fairly calm. A Schweizer tow hook was mounted on the hitch ball and someone sat in the back to pull the cord if necessary. I don't think it was hinged to track the wire direction so I suspect it would have been difficult to release under load. The only drama was how fast the glider climbed compared with aerotow. The biggest problem was the old wire breaking every few tows. It was a big deal to lay everything out and splice the wire a few times so we never did it more than was necessary to get the ground launch sign off for whomever was going up for their test.

I've had a couple of auto pulley tows. Wild! Aileron control before the wing runner even takes a step. These were just to get high enough from a grass strip to turn out over the ridge so I don't know what it's like for a full tow.

Chip Bearden
ASW 24 "JB"
U.S.A.

We do some auto towing at Sunflower in Kansas. Ex Military base, 7000 foot long runway. Surface is roughly the equivalent of The Great Barrier Reef as far as the rope is concerned. The majority of the wear seems to happen when dragging the rope back after the launch, as it does not take too long for all 2000 or so feet to be off the ground. We have cracks in the pavement that has some grass growing up through them, so you can reduce the wear some by pulling the rope back with it in/on that grass. We do not put a chute on the rope, but just let it fall. The fun comes in turning the car around, and trying to be within 50 feet of the end of the rope when it hits the ground. Yep, I have done it. With a full size Chevy G-20 van!

Another option that has been used is a wind up winch on the tow vehicle. Once the vehicle is stopped, the crew goes to the back, operates the wind up winch (have seen both gas and electric version), then drive back, and lay out the rope again.

Pay Out winch probably works better for hang gliders than for our sailplanes, as the car has to go faster than the glider in order to pay out any line.. And in light winds, the glider may need the car to run 60 MPH or more for straight towing, so even faster for pay-out towing. Faster yet for higher elevations (Sunflower is 1500 feet MSL). Gary Boggs has used a pay-out system quite successfully, so it is not impossible to do. Just maybe not so good for the planes that need a bit more speed, unless operating from a drive lakebed.

Fixed pulley at the upwind end opens up lots of possibilities. Especially since the glider can no longer pick up the tow car! Bring on the Z06 Corvettes if you have got pavement! You wanted winch acceleration, now you have got it!

As to wear and tear on the vehicle and its drive train, do an auto tow with a vehicle with an auto transmission that also has a tachometer. Then, drive in the same gear (count shifts from start) at the same speed without the load of the glider. You will probably discover that the torque converter is not locked up when launching the glider (much higher RPM during the glider tow). So, you are generating a lot of extra heat in the transmission on each tow. Best bet for auto tow would be a big block with a manual transmission, and ability to start out in second gear, so you don't have to shift..

It is fun. Get a new car. Get the extended drive train warranty. When the tranny goes out, don't mention you have been launching gliders. :-)

Steve Leonard