[reluctantsparrow]

here is a list of everything used for the above test:
one rope
one bungee restraint for horses
two copper ground clamps
one short DT length with slots cut in the ends

thats it....under 20 dollars for everything. But this rig was only for proof of concept that some sort of leash forced around an obstacle (the DT length halfway down the rear wires) will stop the upward swing of the pilot in the event of rapid deceleration of the hang glider....
There are better ways to accomplish this task....I have many ideas for many devices yet I have no funds. Going to leave it to the big boys to figure it out but my brain is available for hire or a six pack of extremely good beer.
Can it all be made streamlined? Of course it can. I thought of an excellent idea last night that would be totally streamlined in normal flight mode. Does a leash have to obstruct the airflow? Yes, so far I have not thought of any way around that. But the leash is in a line with the airflow and should cause minimal drag.
I inspected the glider thimbles this morning and found zero elongation. I also could not detect any damage to the rear wires where the copper connectors were attached except some flattening of the plastic coating.
I may have sounded harsh in my last post towards those dedicated to maximizing performance on a hang glider by not flying with adequate wheels but that was not my intent.
My harshness was not aimed at those who fly without wheels because they are dedicated to personal efficiency.
My harshness was aimed at those who do not fly with adequate wheels because they want to win a comp and enlarge their ego.
I am not against the jonathan livingston Seagulls among us.
I am one.
I am not against anyone Buzzing launch at high speed to test their own limitations and improve their own skills as long as it does not endanger others in the process.
My harshness was directed towards those who do such things merely to show off. My harshness was directed at those who do not fly with Adequate wheels because they either want to look cool or stupidly assume what happened to their buddy last year could never happen to them.
The ushpa mag is a good example of what I am against. Just look at the paper it is printed on. That mag shows me an organization that does not care about the planet we live on. That nice shiny paper can not be recycled. A very clear message to me of something I want nothing to do with.

[Bill Cummings]

Thanks Jim, for all the work on this proof of concept.
Thanks to all that were the guiding force for this brainstorming session.
Four and a half years and 52 pages -- sometimes good ideas take a while
but I do consider this restraint system proof of concept to be a really good idea.
Using this restraint system along with wheels and a nose skid has great potential
for reducing pilot injuries.
WE SHOULD BE CAREFUL NOT TO JUMP UP AND DOWN AND CLAP OUR HANDS
YELLING EUREKA -- AND POPPING THE CHAMPAGNE CORK -- WE SHOULD KEEP SAFE-SPLAT GOING.
(refining, modifying, combining, improving, and expanding.)

[JoeF]

I am with big ears for RS.
Thanks for your continued quality contributions!

=======================================================

I'm genuinely curious to know what one does on a windy day, after landing, to keep a wing on floats from being blown around or over?

Does one hope that the tow boat is close by?

======================================================

[ARP]

RS,

Well done so far with your rear rigging restraint. Can you try out the front restraint from the control base bar in the same fashion to see if it stops the upward swing? I can see that the base bar is shaped with a forward bow so it might be better to provide two lines instead out at the junction of the uprights and control bar back to the harness. This would also provide a better load line to the airframe via the lower rigging wires and not damage the base bar.

Tony

p.s. in fact a single line is all that is needed between the bottom of the uprights through a link on the front of the harness. This would allow unrestricted sideways movement with the line sliding through the link but with sufficient slack for full pitch. As before it adds another backup if the pilot fails to clip in on his hang loop.

[Bill Cummings]

ARP,
I'm trying to understand how to go about this rigging of the front restraint.
I can see it working for a roll out launch with a aerotug launch dolly but can't picture it when it comes time for the pilot rotating up for a foot landing or when foot launching.
With a launch dolly, care would need to be taken so as not to have the front restraint line somehow snag the dolly. If the complete flight cycle is done on wheels with no need to rotate up to land -- I can see that working.

This discussion now brings to light that a rear restraint system could possibly become entangled with the keel tower on the launch dolly.
What if anything would safeguard against this happening?

Jim, As it turns out I happen to have $99.00, as of this past May, to donate/reimburse you for zip line pulleys. Would that help further the testing?

[ARP]

Bill,

I do not normally tow up so had not considered that scenario. However I'm sure a way could be found to prevent snagging on the launch trolley given enough thought.VG lines hang down and do not usually get tangle up but I guess that could happen as well?

The restraint line(s) to the harness would be made long enough for full arm stretch in pitch either way. That slack would allow the pilot to rotate upright for landing or when foot launching. The slack could be controlled with a light bungee that stretches sufficiently to allow full pitch inputs.

If I have not made it clear then I will do a drawing and post it for you when I get back from Australia.

Tony

[Bill Cummings]

Bill,

I do not normally tow up so had not considered that scenario. However I'm sure a way could be found to prevent snagging on the launch trolley given enough thought.VG lines hang down and do not usually get tangle up but I guess that could happen as well?

The restraint line(s) to the harness would be made long enough for full arm stretch in pitch either way. That slack would allow the pilot to rotate upright for landing or when foot launching. The slack could be controlled with a light bungee that stretches sufficiently to allow full pitch inputs.

If I have not made it clear then I will do a drawing and post it for you when I get back from Australia.

Tony

ARP,
The next time I have my glider set up I can field test the range of motion the front restraint line(s) allow.
What got me wondering was that while standing on launch my head is very close to the keel already.
I'll need that much range of motion.
I think that during a nose over crash the forces involved wouldn't allow my helmet to meet the keel that far rearward anyway.
The forces involved would have my helmet meeting the keel closer to the noseplate. Your explanation makes sense.
I'll see if I can get that ground test on the GoPro.

[ARP]

OK Bill,

If you draw the arc that the pilot follows due to the harness suspension and then do the same for the chest harness it will show where the pilots head will be at any time during a nose in. The further forward the pilot is so the lower he/she would be pulled. When standing upright the pilots head would be closer to the keel.

Tony

[Bill Cummings]

OK Bill,

If you draw the arc that the pilot follows due to the harness suspension and then do the same for the chest harness it will show where the pilots head will be at any time during a nose in. The further forward the pilot is so the lower he/she would be pulled. When standing upright the pilots head would be closer to the keel.

Tony

Front restraint rope added..JPG (18.01 KiB) Viewed 4015 times

What looks like the far downtube is really the hang strap.
What looks like the basetube is really the ARP Restraint Rope.
Imagine the far downtube is hidden behind the nearest downtube.

[ARP]

Hi Bill,

Yes the hang strap and chest restraint strap form a triangle which fixes the pilots head position at a point in space that is away from the keel and the ground. The loads will be directed through the support harness which should spread the load evenly on the body. Provided the air-frame does not collapse the pilot should be in the best position to prevent injury. If the severity of the impact causes the frame to distort or collapse much of the energy will be dissipated in that collapse and so reduce the chance of major injury.

Tony