Reviving Auto Tows!

[Lawrence Spinetta]

The attached Soaring article chronicleing my club's journey in Reviving Auto Tows!  

It is a cost-effective alternative launch method that enables club members to learn new skills.  Please don't hesitate to reach out if you have any questions.  Or, come fly with us at Faul Line Flyers!

   

[Moshe Braner]

Cool!  I've been intrigued by the pulley tow idea, with a pulley on the vehicle and the other end of the rope anchored in the ground.  The advantage is that the vehicle only needs to travel half as far and fast.  (But pull twice as hard!)  The challenge is in constructing a suitable robust pulley.  I'd love to hear from people who have done this.

[Tony Condon]

We did some pulley launches as you describe at Sunflower about 10 years ago. We started with the front rim off a lawnmower tractor. You may find this shocking but is no where nearly built strong enough to handle the rotation speed or the load of a ground launch. there was smoke involved.

Then set up a pully using a trailer hub and rim from Tractor supply. That worked great. It's designed to spin at highway speed and carry a couple thousand pounds. It was set up to plug into the 2" receiver on my Subaru Outback. 

Launch heights were noticeably higher, getting our nosehook 2-33 to 1400 ft instead of 900 or so, for example. But it required twice the length of rope and extra manpower, anchor vehicle, etc. So we have gone back to straight auto tow since that is pretty easy and low stress on our 7000 ft runway.

[Wallace Berry]

For more than a few tows, straight pull auto tow is really only practical on a paved surface.  An unpaved surface is going to beat up the tow vehicle too much and the tow vehicle is going to beat up the surface too much. Pulley launch allows the vehicle to go slow enough that it doesn't get destroyed by driving over a less than perfect surface. Also, pulley launch gets the glider up to flying speed much faster so there is less chance of a wing drop and you get a higher launch. Finally, only do ground launch with a tow release that is capable of automatic back release. DO NOT GROUND LAUNCH WITH A NOSE RELEASE! A Schweizer hook on the chin is not optimum but it can back release if you overfly the winch. A TOST release in the nose is not made to back release. If you overfly the winch and don't release you can find yourself in a rapidly steepening nose down attitude, accelerating at a tremendous rate, and unable to release!

[John DeRosa]

During a week long regatta last fall I watched a group making quite a few auto (and winch) tows.  They were using a quite strong/fast tow truck (I don't remember which brand/model).  It was impressive to watch but they were only able to make pattern tows.  No one "got away" (auto or winch) but then again the weather wasn't all that great for aero tows to 3000 AGL either.

- John (OHM)