Auto Tow

tonycondon

tonycondon

Gastons CRO (Chief Dinner Reservation Officer)
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Tony
Here's a video of one of my friends and I launching our clubs 2-33 behind my Subaru Outback. 2000' rope, we got to around 1000 or 1100 AGL on this launch. Fun and cheap way to get in the air!

https://www.youtube.com/watch?v=mvWk9EapaQk
 
Last edited:
Keep getting an error message on the video.
 
Tony;

1) Very cool. I've never done any ground launch, only aerotow. 2000 ft of rope; 1,000 ft release; my cocktail napkin trig says that's about a 30 deg. angle to the horizontal at release?

2) How long is your runway? You use 2k ft of it for the rope, get up to speed, release, then stop before the end? What does that take?

3) How did you attach to the car? Did you install some kind of release at that end?

I'm curious to learn more about this. My old soaring club usually tows to 3k AGL, but a (cheap) 1k ground/auto tow option might be good for short training flights like pattern work, rope break practice, etc.

BTW, check your URL. I was able to get to the video, but just clicking the link did not work.
 
Inexpensive way for a student pilot to get in a lot of landings when compared with aero tow. We used to use it in the winter months when you were not going to stay up long anyways.
 
DJTorrente said:
Tony;

1) Very cool. I've never done any ground launch, only aerotow. 2000 ft of rope; 1,000 ft release; my cocktail napkin trig says that's about a 30 deg. angle to the horizontal at release?

2) How long is your runway? You use 2k ft of it for the rope, get up to speed, release, then stop before the end? What does that take?

3) How did you attach to the car? Did you install some kind of release at that end?

I'm curious to learn more about this. My old soaring club usually tows to 3k AGL, but a (cheap) 1k ground/auto tow option might be good for short training flights like pattern work, rope break practice, etc.

BTW, check your URL. I was able to get to the video, but just clicking the link did not work.
Click to expand...

our math checks.

runway is 7000 ft long. we usually use about 6000 ft of it on a launch

there is a release on the car. guy in the club fabricated one based on a schweizer release that slides into a 2" receiver.

its quite possible we could get a higher launch with a shorter rope. a few weeks ago we were experimenting with 3000 feet of flat poly weave "pull tape" and we definitely weren't getting as high as we did when we switched to 2000 ft.

http://www.coloradosoaring.org/thinking_pages/ground_launching/winching/john_campbell.htm
 
How does the rope attach to the glider? Normal tow hook or do you have a CG attachment?
 
Nice, we need more non tow plane launches in this country.
 
We use the normal aerotow hook on the 2-33. There is an option to install a ground launch hook which improves height gained by about 10% but we dont have it
 
Great video Tony!

We auto tow on a dry lake twice a year. What diameter rope? Amsteel?
We use 5/16 3ply poly, 1800 ft and can easily get 1000ft AGL with the 2-33 or 1-26 standard chin hook. We tow behind a 5.7L Tundra or Chevy 2500 diesel.

Our "run" is about the same, once you are at altitude, why keep driving. Getting much more altitude puts a greater strain on the rope and rope breaks will occur more often.

One thing to consider with the 3000ft tape. The weight of the rope is added to what the glider has to lift, consider the weight of throwing most of that rope in the cockpit and compute the GW of glider, pilots and rope. Also consider the drag of the rope. Once you stand that rope up, ground to glider, you have a lot of "frontal drag" with the rope cutting through the air. The rope will bow a bit as you pull it through the air.

Pull it tight enough and you can hear the rope sing with a low hum.
 
The flat tape would have a bunch of drag. The winch will often use a 1/8" armored steel cable, very little drag and plenty strong. The armor is a thin strip of steel spiraled around the cable to prevent cable wear due to abrasion as its dragged along the ground.

Dan
 
Gee Tony, when do I get a ride? :p

Nice video! Using a car has got to be one of the cheapest ways to get a lap in the pattern. Sometimes I think the mustang has the same glide ratio. Hehe
 
BillTIZ said:
Great video Tony!

We auto tow on a dry lake twice a year. What diameter rope? Amsteel?
We use 5/16 3ply poly, 1800 ft and can easily get 1000ft AGL with the 2-33 or 1-26 standard chin hook. We tow behind a 5.7L Tundra or Chevy 2500 diesel.

Our "run" is about the same, once you are at altitude, why keep driving. Getting much more altitude puts a greater strain on the rope and rope breaks will occur more often.

One thing to consider with the 3000ft tape. The weight of the rope is added to what the glider has to lift, consider the weight of throwing most of that rope in the cockpit and compute the GW of glider, pilots and rope. Also consider the drag of the rope. Once you stand that rope up, ground to glider, you have a lot of "frontal drag" with the rope cutting through the air. The rope will bow a bit as you pull it through the air.

Pull it tight enough and you can hear the rope sing with a low hum.
Click to expand...

we typically use either 5/16" or 3/8" diameter hollow braid poly. in the old days we had some armored steel cable but we've been using this type of rope for a couple decades now i think. this winter we've mostly been towing with my 2014 Subaru Outback 3.6R. Amsteel/Spectra will not hold up to our WWII era runway, it is highly abrasive.

We were only planning to do a few straight auto tows with the 3000' length, to make sure it would hold up OK. Then we were going to use some pulleys to try some 2:1 reduction launches. Didn't get that far.

Dan Thomas said:
The flat tape would have a bunch of drag. The winch will often use a 1/8" armored steel cable, very little drag and plenty strong. The armor is a thin strip of steel spiraled around the cable to prevent cable wear due to abrasion as its dragged along the ground.

Dan
Click to expand...

We wondered about the drag but I talked to a guy in Texas who has been launching a 2-33 with it and he said their experience was that the rope gets plenty of twists in it and doesn't flutter too bad. It definitely does sound different on the launch than the hollow braid poly.

My understanding is that insurance is not available in the US for a winch using steel cable.

Tristar said:
Gee Tony, when do I get a ride? :p

Nice video! Using a car has got to be one of the cheapest ways to get a lap in the pattern. Sometimes I think the mustang has the same glide ratio. Hehe
Click to expand...

let me know the next time you'll be in town for a while, we'll get you up for a launch. Quite fun to get to 1000 feet or higher in less than a minute.
 
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