Launching a single skin (SS) paraglider (PG) on KitetiK is not trivial. The span of my 28sqm Advance Sigma V is about 12m. The longest part of the trampoline on which the canopy can be laid out is about 6m - between the beams at the leeward (long) hull. So there's an extra 6m of canopy that's a problem even before you try to launch. The bridles, plus risers, are about 8m long. These two length constraints are acommodated by
- launching only about the middle 6m of the span, with the wing tips constrained; and
- running the bridles from the canopy, through rings which are controlled by lines to the windward hull, then back to the mast base (immediately behind the canopy)
A very successful test was conducted yesterday. In this video there is voice commentary, but it is sometimes dominated by wind noise. The breeze was a fairly steady 8 - 11 knots.
The PG was in the air for 20 minutes or more with no requirement for active (steering) control. Although stability with separated tow points on short lines had previously been well demonstrated, the revelation yesterday was that even when the launch control lines were slack, so all load was on the risers directly to the mast base, a couple of light "guy" lines were sufficient to stabilize the wing - OK, these guys clearly takes some of the load....but sufficiently little that it was easy to install and remove the carabina connections. This is important as, if the wing can be launched to the risers tethered at the mast base and be stable there, this allows time to add some rigging for the rest of the launch sequence. Eventually I expect no such requirement for stability as the rigging can all be installed prior to launch - but, while developing such procedure, this is a very handy attribute of the system.
Although the reefing looks quite effective (eg at about1:50), it was not useful/effective for launching. I'll try to develop it further for that purpose. But yesterday I eventually removed the reef in order to launch. Although the wingtips did get a little wet, they didn't hold any water so it wasn't too bad. But this aspect of the procedure definitely needs to be improved/developed.
For those of you who understand aeronautics and PGs better than me, feel free to make suggestions as to how important it might be to tighten the TE when the canopy is not fully deployed. You'll see plenty of flapping in the video. Although it seems to fly OK, it would no doubt be even more stable if the TE was working correctly. I presume that the TE is tightened by spanwise pressure when the full canopy is open - but this is not available when the wing tips are not "flying". I may drop some lines from the D final bridles to the TE just in the centre of the span (where there are no brake lines). But I'm open to other suggestions.
Note that during yesterday's launch, KitetiK was actually on the mud rather than floating. This was not a problem in the light wind. But I'll need a much better anchor to hold in mud, when floating, in stronger wind.