Hi Folks,

A Swift pilot friend sent me some photos showing details of a bungee launch system he came across in France this summer, which I thought might be of interest. You can see the photos by going to:

Home - Articles - A Bungee Launch System

carbon-dragon.ihpa.ie/index.php/home-top...bungee-launch-system

We're planning to knock one of these up here in Ireland for launching his Swift and my CD

Phil.

Is this the system you used for you first test tows? I've been thinking about a system to try to launch my Cd from a hang glider mountain site. I only have about 100 feet from the trees to the edge.

Hi Rick,

No, the system, above, belongs to a French pilot. Ken (a Swift pilot / hangie and machinist - very handy bloke to know!) put together a new bungee system over the winter:

carbon-dragon.ihpa.ie/index.php/cd-build...bungee-launch-system

We initially started with (I think) 6 x 17m bungees but they didn't have quite the 'Oompf' to get the Swift airborne from a flat field, so we doubled the length of the bungees (linking the extensions to the original ropes using light weight aluminium carabiners)... and the results were most pleasing!


I can post more photos and detail of the bungee system components if you like. The bungee rope we used is not the normal (agricultural variety) but has about double the energy density - pricey, but worth it.

Phil.

...forgot to mention...

We used 10mm diameter bungee rope from Sandowtechnic.com, which yields around 22daN / 22Kg of force when stretched 75% beyond its unstretched length. I would be reluctant to use anything thicker than 10mm as this is on the limit of what a single person can safely stretch on their own - and even then, one slip and you can launch yourself 'over the back!'

Phil.