So far, all of my glider launches have been by aero-tow. I would like to
broaden my experience a bit, and try some sort of ground launch. I'm trying
to interest my club here in San Francisco in trying auto-towing one
weekend. How much should we expect to spend on the gear? It basically comes
down to the tow-cable, doesn't it?

Johan Larson

On Jan 28, 7:58 pm, Johan Larson > wrote:
> So far, all of my glider launches have been by aero-tow. I would like to
> broaden my experience a bit, and try some sort of ground launch. I'm trying
> to interest my club here in San Francisco in trying auto-towing one
> weekend. How much should we expect to spend on the gear? It basically comes
> down to the tow-cable, doesn't it?
>
> Johan Larson

It depends. Do you have a release available? For one time you can
buy cheap polypro rope for around $100. Good rope will run several
hundred if you want to do more than a weekend. Also dragging the rope
around will wear it out pretty quick.

Tim Taylor wrote:
> On Jan 28, 7:58 pm, Johan Larson > wrote:
>> So far, all of my glider launches have been by aero-tow. I would like
>> to broaden my experience a bit, and try some sort of ground launch.
>> I'm trying to interest my club here in San Francisco in trying
>> auto-towing one weekend. How much should we expect to spend on the
>> gear? It basically comes down to the tow-cable, doesn't it?
>
> It depends. Do you have a release available?

Mumble. We probably have an extra one around here somewhere, but we would
need to find a way to attach it to the truck, presumably on the tow hitch.

Do we really need one, or would it be enough to keep a pair of cutters
handy?

> For one time you can
> buy cheap polypro rope for around $100. Good rope will run several
> hundred if you want to do more than a weekend. Also dragging the rope
> around will wear it out pretty quick.

Johan Larson

On Jan 28, 6:58 pm, Johan Larson > wrote:
> So far, all of my glider launches have been by aero-tow. I would like to
> broaden my experience a bit, and try some sort of ground launch. I'm trying
> to interest my club here in San Francisco in trying auto-towing one
> weekend. How much should we expect to spend on the gear? It basically comes
> down to the tow-cable, doesn't it?
>
> Johan Larson

Ha, Fort Funston would work for that.....make a some sort of runway
next to the parking lot, all you would need is really 200 ft of
rope...and than you can stay airborne for quite some time....and it
would be cheap....

Jacek
Washington State
ex- San Francisco

For the last few years, auto tow has been provided, during the trip to the
Alvord Desert in SE Oregon, by a bronze 1973 Buick Riveria. It has the
vinyl top, which is shredded. It has no grille. It is full of mouse
excrement. It is stored at a famous ranch for 11 months and 3 weeks. It
has a 450 cu inch engine. It is rusted badly. It looks like a piece of
crap and is known as the "brown turd".

We have a long tow cable and can get over 2,000 feet of altitude druing a
launch. Last year it got real tired and we put one of the new SUVs into
service. That worked great and had air conditioning.

If you have only done aero launches, just remember: stick forward to slow
down, stick back to speed up. If the cable breaks, everything in the
cockpit will be on the ceiling, at which time you push the stick forward
without undue delay.

Colin

I dont understand -stick forward to slow down? Can you expand on that a little?

Thanks, Bagger

The car is going at a steady rate. The slowest airspeed is when you are
flying level. You will be flying at the same speed that the car is moving
forward.

If you pull back on the stick, you will start climbing. Your speed parallel
to the ground stays the same as the car. However, you have now added a
vertical speed vector. Your airspeed is the combination of these two
vectors.

Basic physics.

Mike Schumann

"bagmaker" > wrote in message
...
>
> I dont understand -stick forward to slow down? Can you expand on that a
> little?
>
> Thanks, Bagger
>
>
>
>
> --
> bagmaker



--
Posted via a free Usenet account from http://www.teranews.com

This is theroetically true. However, unless the tow vehicle is particularly
powerful and the glider is small, the glider will be able to generate enough
retarding force on the tow car to slow it down. In effect, making the
operation more like a constant tension tow. With a constant tension tow,
the glider pilot can control airspeed with pitch in the normal way i.e.
raise the nose to reduce airspeed and lower it to increase it.

So, whether the airspeed increases or decreases depends on whether the
glider can control the tow vehicle or the other way around. For example,
towing a 1-26 with a large powerful truck the airspeed will increase as the
nose is pulled up. The 1-26, like most Schweizers, has the hook is too far
forward and the elevator is too small to significantly load the tow car.
Towing a large 2-seater equipped with a true CG hook. the glider will slow
the car. I've seen it work both ways.

Some more enlightened auto tow operations use a hydraulic tensiometer on the
tow vehicle. The driver adjusts the throttle to hold the cable tension
equal to .7 - 1.0 times the glider GW. The vehicle speed is then whatever
the glider allows it to be.

Bill Daniels


"Mike Schumann" > wrote in message
.. .
> The car is going at a steady rate. The slowest airspeed is when you are
> flying level. You will be flying at the same speed that the car is moving
> forward.
>
> If you pull back on the stick, you will start climbing. Your speed
> parallel to the ground stays the same as the car. However, you have now
> added a vertical speed vector. Your airspeed is the combination of these
> two vectors.
>
> Basic physics.
>
> Mike Schumann
>
> "bagmaker" > wrote in message
> ...
>>
>> I dont understand -stick forward to slow down? Can you expand on that a
>> little?
>>
>> Thanks, Bagger
>>
>>
>>
>>
>> --
>> bagmaker
>
>
>
> --
> Posted via a free Usenet account from http://www.teranews.com
>