Kenny,

I have been thinking something similar for the cockpit structure. The beams on the side are analgous to the hang tubes on the parallel bar hang gliders (Icarus II, Icarus V, Easy Riser, Swift, Millenium, Voyager, etc). The keel is like the structure on the Super Floater or the ULF-1. I'm inclined to make round tubes for each and taper them forward and join them together at the front. I would put a wheel centered on the tube behind the pilot just aft of the CG and a small nosewheel.

I also am not that interested in foot launching very often. I would only foot launch in winds of 15 mph and above where the tail was flying. I think it would be very straight forward to foot launch in those conditions. I imagine most flights on a hill would be a roll off launch or a bungee launch. Most flights in the flat lands would be from some kind of auto tow, winch tow or aero tow. The landings are another story. I would probably only do that once, to get it on video. I am 56 and don't run all that fast any more. I also weigh about 225 in the mornings, so the stall speed will be up there.

The basic cockpit structure would consist of the parallel bars and keel that come together at the nose. This would be covered by a lightweight fairing in the nose and a small windscreen in front of the pilot. I would like to have some gear doors and a canopy that could be added for high, cold flights, but would most often fly the glider without the complication.

The layouts I did for the WinDancer had a quarter chord forward sweep of about 6 or 7 degrees, about like a Blanik or Ka-13. This allowed balancing with a heavy pilot (me) with no tail ballast. The downside was that a lightweight pilot would have to add nose weight for balance. If a lightweight pilot did not add noseweight, there is the possibility of spinning and not recovering, so there is some operational risk that would have to be taken into account.

The flap interconnect system designed by Dick Schreder on the HP-18 was remarkably simple. It used a rotating cam to drive the aileron pivots up and down. The rotating axis was in line with the flap axis allowing a straight plug into the flap root ribs for automatic control hookup. It was even simpler than the spoil flap on the Carbon Dragon and far more effective. It is worth a look.

I am not really interested in making a record flight only design. I would like to have a glider that is optimized for frequent operations and still fits the O-4 and Part 103 rules. It should handle very easily and have decent performance, with more emphasis on easy flying than high performance.

I also like the Archaeopteryx. It reminds me of an optimized Carbon Dragon and sure looks like it flys well. The issues we have been discussing with visibility seem less than optimum to me and the cost is a deal killer for almost everyone. A good ultralight sailplane design should be one of the least expensive aircraft around, not one of the most expensive.

Dan

--- In This email address is being protected from spambots. You need JavaScript enabled to view it., Kenny Andersen wrote:
>
> Dan,I’ve been thinking that perhaps the cockpit structure could consist of a couple of box beams on either side of the cockpit that converge and get shorter and narrower at the nose.  This might support a diverging design for either a couple of wheels like the Axel or a single keelbeam that could be straddled at launch and then slid on during landing, like the ULF-1 (or maybe with a couple of small wheels attached by an axle that goes through the keelbeam).  Either way, if the structure is on the sides, then the center could be flexible for whether you intend to foot launch or not.  Who-ee though -- 155 Lb to foot launch would seem mighty ambitious!  I’m 53 and run, cycle, weight train and swim, and I’m thinking that’s something that I wouldn’t even think about.  You got bigger cajones than me!The cockpit structure would of course be made compatible with the current wing, since I really don’t have the expertise to redo it.  I’m
> guessing a few degree forward sweep from where it is at now would have a low impact on the handling, but should help a lot with the weight distribution. Ever seen winglets on a forward swept wing?
> The flaps sound interesting, but all that complexity would be guaranteed to add some weight a system complexity.  Did the model you flew in have the air brake like the magic dragon?  Wouldn’t that be enough?  I know it doesn’t seem as flexible or as sophisticated, but it would appear to be WAY simpler. There may be a difference on say a record-breaking version vs. the one everybody wants to flay around in…
> I really like the Archaeopteryx too, but no way would the significant-other let me pop that much for a toy!  She’d much rather I putzed around in the garage for a decade building one.  Sill, what we are talking about here really is pretty much a deluxe hang glider…
> As always, we appreciate and welcome your input.Kenny