[Rick Masters]

Hang gliders have penetration.

Paragliders don't.

[ARP]

Ram Air Section Technology:- https://vimeo.com/155841594

It may not be the solution to the problem, just yet, but it does show an awareness of it and willingness to try and remedy it.

The cynics amongst us might just say it is a ploy to deceive the punters that PG's can be safe. On the other hand if the system has merit then it should be applauded as a first step to achieving a better safety record!

[JoeF]

mm provided a rough translation"
===============================
Sun Feb 28, 2016 3:48 am Post subject: RE: Ram Air Section technology - by Swing - better safety
Rough and ready video translation.

What we pilots fear:

Large surface asymmetrics.
Front collapse with front rosette.
Getting lifted in higher wind launch.
Overshooting while reverse launching.
Reduced control in turbulence.

Is faced by Swing with an innovative idea!

RAST

The first bulkhead partition for controlled pressure areas in paraglider.

The system, invented by Swing, for controlled pressure areas produces:

While starting.
1. The front pressure area fills first.
2. A self stable profile is developed which does not overshoot or lift the pilot.

Simulation of how the canopy inflates.

The canopy inflated front first. The lift force is generated gradually.

During reverse start, the wing doesn´t overshoot but takes off sooner.

In Flight.
1. Maneuverability remains complete, even in extreme turbulence.
2. Nice "pull into thermal" instead of hanging back upon encountering lift.

Normal flight: bulkhead open top and bottom.

Disturbed flight: bulkhead closes top and bottom.

and above all...
... with RAST, paragliders become clearly safer.

On a paraglider, the great thing is that excessive energy is dissipated by deformation. For that it is enough that the lifting, front section of the profile deforms.

It is only when the back section strongly deflates and the fold extends beyond mid wing that asymmetrics and frontals become a problem.
RAST acts effectively against precisely this.

A frontal with RAST

New with RAST...
during an asymmetric or a frontal, the front section acts as a crumple zone like in cars. It deforms.
This is the BUFFER Section.

Any deformation in the front section produces an increase in pressure in the back section, thus avoiding excessive emptying.
This is the CORE Section.


If the CORE section remains inflated, turn rate, altitude loss and dynamics during asymmetrics and frontal become complete non-problems.

Asymmetric at full speed
The rear section also folds but a a very reduced angle, it does not deflate completely.
center of the wing immediately flies again.

With RAST it is extremely difficult to create large collapses
this is where RAST works

In order to get a large collapse, the pilot needs to pull both, A and B risers.

Extremely fast opening with little height loss even during 100% frontals

We don´t want to leave the most important question unanswered...
What does a comparison look like between a wing with and without RAST?

Wing without RAST
-only one hand to pull collapse
-faster course change
-higher dynamics
-more height loss
-stronger shooting

Wing with RAST
-collapse pulled with two hands
-slow change of course
-little dynamics
-barely any height loss
-only light shooting
_________________
===========================================
http://www.paraglidingforum.com/viewtopic.php?p=p488055

[wingspan33]

. . .The cynics amongst us might just say it is a ploy to deceive the punters that PG's can be safe. On the other hand if the system has merit then it should be applauded as a first step to achieving a better safety record!

It seems odd to me that (water based) kite board "riders" have had wings with inflatable leading edges for many years. This is mainly to keep them floating when the canopy falls into the water. But it also just about 100% prevents what in a PG would be a collapse. Now why haven't collapsible canopy manufactures adopted/adapted this technology?

As far as first steps go, . . . ram air gliding/soaring parachutes were around in 1973 (as illustrated in a Dan Pointer book I own). That makes it 43 years gone by now to take a "first step" toward a safer soaring parachute? A number of years ago (4-5) I saw something about a manufacturer putting tiny (~1/16 inch) carbon rods/ribs into their collapsible canopies. That was suppose to help prevent collapses. What happened with them. Any of those canopies suffered a collapse anyway?

The collapsible canopy industry wants to make cheap, affordable, high profit products that are easy for a student to learn on. That plan makes it more likely for the student to buy their own NEW collapsible canopy. So, following this recipe, do the manufacturers really want to make a more complex, more expensive to produce product? A product that low skilled workers can't easily make (for pennies on the dollar) with consistent quality? A product that requires above average SKILLED workers (who you need to pay more)?

At this point in time, new PG's cost similar to, at least, entry level hang gliders and they only last 3 or so years compared to a 10-20 year life span of a well cared for hang glider.

When it comes down to PGs, the following old saying seems to fit pretty well - "You can't make a silk purse out of a sow's ear."

However, it could be that a "sow's ear" might be less prone to collapse!

[Rick Masters]

How many years did it take to solve the divergence problem with hang gliders?
Four years?
Who made that happen?
R.R. Wills, the USHGA Accident Chairman, and the US Hang Gliding Manufacturers Association.
The German Hang Gliding Association (DHV) also played a major role.

But how long is it taking to solve the collapse problem with paragliders?
Call it 1986 to the present. Thirty years.
If you look at absolute numbers of fatalities - no progress at all.
Why?
Well, for one thing, if you make paragliders non-collapsible, they will tend to surge underneath the pilot in turbulence.
Try that on landing approach.

My opinion - more than an opinion, really - is that you can make a ram-air rectangular parachute more dangerous by increasing the aspect ratio.
You can make it more dangerous by giving it a more critical airfoil.
BUT YOU CAN'T MAKE IT SAFER.
The period of time that has elapsed without significant improvement; the uniform yearly fatality numbers from PDMC collapse; the horrible numbers of maiming injuries all clearly indicate that anything that could be done has already been tried.
It also clearly demonstrates to me that the USHPA is not particularly concerned and is no longer competent.

If you have a field of participants that are not concerned with safety, that's one thing.
Mixing it with hang gliding is another.
We should separate the sports based on the failure of paragliding to improve its safety record.

- Form a national hang gliding association to focus on the safety of hang gliding -

[ARP]

If you follow the reasoning that that the PG wing needs to collapse, if the pilot's weight is unloaded from the lines, then the wing will not continue flying in a downward arc into which the pilot falls. Putting in a rigid structure, to prevent collapse, keeps the wing flying and without the pilot weight it becomes divergent. The CF strips were not to prevent collapse but to keep the vents open for rapid re-inflation after collapse.

This "new " idea prevents a complete collapse and is enough to stop the wing flying forward and getting tangled with the pilot. It remains to be seen how effective it is in stopping the wing from folding up in turbulence. By controlling the pressure in a particular section of the wing the manufacturer claims to have solved a few other control issues. We will see in time if they are correct.

I have not seen what the price difference is with or without RAST but if the wing is safer do you not think that it would be worthwhile investment? I doubt that the production costs would be that much greater and only a few % increase in cost for safety is a good investment.

[Bill Cummings]

Ram Air Section Technology:- https://vimeo.com/155841594

It may not be the solution to the problem, just yet, but it does show an awareness of it and willingness to try and remedy it.

The cynics amongst us might just say it is a ploy to deceive the punters that PG's can be safe. On the other hand if the system has merit then it should be applauded as a first step to achieving a better safety record!

Having only looked at the video and not having run the text through Google Translate is it the inner, side baffles that resist deflation that yield a greater tendency to maintain the desired overall airfoil?

[ARP]

It looks like a span-wise buffer section bulk head at mid chord that provides the necessary pressure retention. The leading edge still folds in to reduce the forward momentum of the wing preventing it overflying the pilot. Joe's translation describes the action.

[Rick Masters]

Did I mention that hang gliders have penetration and paragliders don't?
=========================
March 1, 2016
Eleven paragliders crash in Nepal
During Paragliding World Cup eliminations, "eleven gliders crashed, after a strong gust of wind. Seven of the pilots fell in Phewa Lake, south of the city. Another pilot fell into a tree and the other three landed in different parts of the city."
http://www.rtl.be/info/monde/internatio ... 98746.aspx








http://myrepublica.com/photo-feature/story/37980/paragliders-accident-in-pokhara.html

Mark my words, one of these days we'll see a dozen or more soaring parachutists killed in a sudden wind event.
There won't be enough helicopters to collect the bodies.
Wind events are very common atmospheric phenomena.
I have encountered them on several occasions in very fast hang gliders, outrun them and landed safely in front of them.

- Don't bring a noodle to a gunfight: Fly a hang glider -

[Rick Masters]

http://www.nbclosangeles.com/news/local/Paraglider-Caught-in-Dust-Devil-Plummets-60-Feet-Survives--375712761.html
Paul Mattson survived a 60-foot fall after he says he and his canopy got caught in a dust devil near Cal State San Bernardino on April 2, 2016.

- Don't bring a noodle to a gunfight: Fly a hang glider -