Kenny,

I helped build the prototype Carbon Dragon and flew it about 30 flights during development. I'm about 6'-2" and my eye line was just about even with the bottom surface of the wing with my head against the head rest. On several of the flights I flew with other gliders in thermals. The Carbon Dragon was pretty blind for me. In one thermal with 5 other gliders near my altitude, there were times that I could only see one other glider and couldn't keep track of the others. I flew away from the thermal because of the poor visibility and risk of collision.

I talked with Jim Maupin about the configuration and why he chose a shoulder wing. He said that the flow over the wing would be better for climbing. The glider was designed originally as a prototype to set world records with a lightweight pilot (Rich Pfeiffer). The maximum pilot weight was planned to be 150 lbs and all of the structures were designed for this load. I weighed 210 pounds when I flew the glider, which far exceeded gross weight and required an additional 12 pounds of weight to balance near the forward limit. I flew the glider very gingerly to keep the load to a safe level.

I think that redesigning the Carbon Dragon with a mid-wing and strengthening the structures for heavier pilots is a great idea. The Carbon Dragon handled beautifully and climbed exceptionally well. A mid-wing would allow better visibility and moving the pilot aft several inches. Almost all the ultralight gliders that I have been around have been quite nose heavy. Eric Raymond's Edelweiss in its original configuration required a lot of tail weight. The Light Hawk had a little forward sweep to account for this problem, but is still requires tail weight for heavy pilots. In ultralight gliders, the pilot represents a far higher percentage of the gross weight than regular gliders, so the pilot needs a shorter moment arm from his CG to the CG of the system.

Good luck with your interesting project.

Dan Armstrong

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From: Kenny <This email address is being protected from spambots. You need JavaScript enabled to view it.>
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Sent: Fri, October 14, 2011 3:26:53 AM
Subject: [Carbondragonbuildersandpilots] Re: Improving the pilot's field of view


Perusing some photos of S. Abbet's CD build and it's easy to see what the concern is about visibility. The wings would have to be spread a bit to be lowered, but looking at the other photos, that approach doesn't seem insurmountable. Moving the pilot down, not only puts the pilot CG forward, but adds to the overall frontal area (it seems), so does anyone see any obvious problems with moving the pilot up to the woodstock-type location? Seems like visibility would get much better. The moment at the wing root wouldn't change.

www.carbondragon.ch/Book%20du%20Carbon%2...ier%20vols/index.htm

--- In This email address is being protected from spambots. You need JavaScript enabled to view it., "Kenny" wrote:
>
> so how about going the other direction like the pics of the woodstock that I posted. You'd keep the CG more aft since less prone, and you'd improve the visibility... I would think. Going more prone, as you say, would seem to take the DC forward, and there is [apparently] already a problem with that.
>
> --- In This email address is being protected from spambots. You need JavaScript enabled to view it., Steve Adkins wrote:
> >
> > I co-owned a Schweizer 1-35c which came either with a removable canopy or a hinged canopy supported by gas springs. There is a large weight penalty for the latter. The hinged option coupled with a heavy wing repair put me over the gross weight limit for a period where I did not fly the aircraft.
> > www.carbondragon.us/steve_redsailplane_sm.jpg ... me in N135EX
> > members.goldengate.net/~tmrent/soar/docs...5_files/image002.jpg ... on final
> >
> > The mockup I built of the pilot pod included the huge wing root ribs (Steve Arndt sat in it). The wing is really a view blocker. A more recumbent position may help lower the eyes below the wing but that position moves the pilot's body and feet forward; thus, moving the CG forward which in turn lowers the maximum allowable speed when under tow according to the CG envelope. Also, extending the forward length of the pilot pod results in more side area in front of the CG; thus, impacting flight stability (for good or bad?). (The domino effect of design changes.)
> >
> > S. Steve Adkins (Note: not Steve Arndt)
> > carbondragon.us/ ... dormant website with New Photo