Wednesday, April 14, 2010

Impressions of a 2 line glider

Times are changing. Within a year from now, It's very likely that all pilots who are very serious about their ability to be competitive on the pwc or FAI Worlds level will be flying a 2 line glider.

It's not rocket science, really. The obvious reduction in line drag is substantial and the resulting performance increases are sometimes subtle but more often quite obvious.

Personally, with the introduction by Ozone of the R10.2, I was quite skeptical of how successful this glider would be in gaining acceptance and at building confidence with the pilots who are flying it. When I lay the lineset across the palm of my hand and think about those times when I've come cascading out of the sky, stalling and restarting, and then doing it again to clear a hopeless cravat, I honestly question how the glider would hold up in terms of trim and longevity.

The R10.2 is very light in comparison to the IcePeak3 and Boom 6/7. The upper cascades are super thin, and some have commented that the lower fabric is very light weight and is known to stretch and have a very short life span.

The performance of the R10.2 is stellar and in flight it seems to fly and handle as any other comp wing. The only glider that suffered a major cascade of events during the 2 days in Pocos was in fact an R10.2, but as many pilots with no experience on a comp glider have purchased one, this isn't the least bit conclusive.

The R10.2 must be treated with extreme care when launching in windy conditions, or when launching from snaggy ground. I saw first hand a brand new R10.2 with 6 of the plastic stiffeners which provide the structure to the leading edge ripped from their attachment area. The pilot simply attempted to launch in stronger winds with his glider in a mushroomed position. He just started the middle of the leading edge into the wind, and the trailing edge snagged. As soon as he felt resistance he also felt a strange popping feeling and after he aborted his attempt and inspected the glider he found the center section of the leading edge support structure failed. From what I understand there is no field fix for this and must be repaired at the factory.

There were a few R10.2s with broken upper cascade lines but there were others as well and this is to be expected with lines so thin which may show impressive results when load tested, but cut with the smallest resistance when snagged.

While making several long glides with several R10.2s, initially it didn't seem like there was any noticeable difference with the Boom 7, but by the end of the race it seemed quite clear to me that the difference in line drag was adding up. The consensus amongst the pwc pilots also very strongly agrees with my personal observations....

The only real question remaining with me is how will this glider behave in very strong conditions? My very knowledgeable friend who flew in the Montegrappa in Italy which was another first look at the R10.2 feels that the glider is very predictable in strong conditions.

One thing that any pilot will marvel at is how this glider remains pressurized and overhead when you are 100% sure that it is going to frontal on launch. I witnessed this over and over again as most of the pilots flying the R10.2 had little to no time flying or kiting it. When they attempted to launch in windy conditions, it was virtually the same scenario repeated over and over: Very experienced pilot pulls up and is instantly surprised at how fast the glider rifles over head and jerks him / her off the ground in a reversed position. In several of these situations, the glider moves ahead to a point where it is strongly unloaded, and way out in front of the pilot, yet it doesn't frontal when you're expectation from you're experience tells you that this glider simply must frontal....

How does this characteristic of the glider play out in flight when you encounter a strong wind shear or other turbulence? Maybe this anti frontal characteristic is a very strong quality of the glider and will carry over to inflight qualities as well.

There is still confusion as to how best to be loaded with the R10.2. Initially, pilots purchased the glider at a weight where they would be in the lower third of the loading, but apparently this changed and they were then told to be loaded towards the top of the range. This was evidenced by several R10.2s being sold in Pocos with the explanation being that they needed a smaller one....

In summary, the only first hand info I have which I can express with confidence:

1. This glider is very light weight and seems kind of like an XAlps version. It will be interesting to see how it holds up with heavy use.

2. If you launch this glider in windy conditions and snag lines, there is a chance that instead of just popping a line or two, the leading edge structure will fail as the weed whacker stiffeners separate from their attachment points.

3. Because of the light weight of this glider, it is very easy to accelerate. This was the most common characteristic of the glider that I heard...

4. In terms of gliding performance, this glider is the strongest production glider available today. This may change in the year to come as the Niviuk, Gin, U5, and other 2 line protos are completed.... Ozone has taken us one giant step forward in terms of our reach with a paraglider and the race is clearly on to expand on Ozones success.... Who knows where this will go, but right now my $ is on Aljaz Valic and the Nivuik 2 line protos. Aljaz has designed his own proto which seems very strong. As he is also one of the true bird people, it's hard to make any conclusive report but time will tell. Niviuk will be deciding shortly whether to go with Aljaz's or another Niviuk 2 line proto..... They will be producing enough protos for the Niviuk team pilots to fly at the Europeans so that will certainly be an interesting competition to watch! No information from Gin on his 2 line effort so can't comment on that one....

Jack

6 comments:

Brett Hardin said...

great info, thanks Jack

Stefan Mitrovich said...

yeah I second that. Interesting to note how it was mentioned as a "throw away" glider. I guess now what is left is to advance the materials in such a way as to prolong the life of this design.

Tim said...

Great writeup Jack -

Marketo said...
This comment has been removed by a blog administrator.
Jack Brown said...

Marketo if you make it back to this page, please contact me at akparajack@yahoo.com, and I'll explain to you exactly how I came to various conclusions.... Also, I now have an R10.2, and look forward to flying it...

Jack

Anonymous said...

Good insights. Interested to hear how you like your R.10.2. There is a dearth of objective info about the 2 v 3 line wings in general.


Also wondering what one has to say in order to get censored by these nefarious blog administrators....