LBarron

You mention that the Fraser airfoil would be good for an ultralight up to a 60mph which as I understand it is about the limit for a US ultralight but the UK SSDR has no max speed and a stall not exceeding 35 knots. Would the airfoil be good for a higher speed if the power was there?
If I could be confident of the wing design and if it would give a reasonable cruise then I think I would build.

As regards the wing, my knowledge of design and analysis is quite limited. I'm slowly getting a better understanding. I had looked at the Fraser airfoil and wondered if it would be a suitable replacement but as I say, I lack the knowledge and confidence to do any meaningful analysis.
I'm looking forward to your model results. I had considered building one myself but have been put off by comments that models don't translate well to full scale, I don't know how true that is. In the past I've built a lot of RC models and in my experience you can make anything fly no matter how bad the design.

I've contacted as many people as I can who have expressed interest in the p/v. It has so many attractions as a low cost simple machine, but everyone has the same doubts and reservations, if the wing could be fixed and the cruise increased I'm sure it could be quite popular. In the UK, there is a new (more liberal) SSDR (single seat deregulated) category, which has superseded the ultralight category which was broadly similar to the US ultralight category. In fact even current regulated ultralights/microlight machines will ultimately be deregulated if they come within the specification. The Vampyr would suit the category well.

Hi Leland

Thanks for the reply.
I have followed the yahoo group and through it I contacted another potential builder called Bruce Keeping who lives in Cornwall. He has spoken with Regis the French builder, and apparently it was overweight, not as per regs but just simply too heavy. Regis told him that he'd wished he'd built the spar with Graphlite and used other weight saving measures, presumably glass fibre rather than wood. I think he gave up as Bruce has heard nothing more.

Hi Leland

I've been looking through an old thread on the Debreyer Pelican/Vampyr to which you contributed. Reading through it, it seem you had ideas to build one. I have been contemplating doing so and have a copy of the plans. I see from your posts that you had questions regarding the wing, which I also have. Did you come to any conclusions about the wing especially concerning the pedestrian performance. I understand the aerofoil is the Fauvel F4, which seems to achieve so much more on the AV36.

Regards

Mark

Not sure,...so I'll ask,...is this "John Knolla(sp?)" who use to come to my "ducted fan booth" the "XLD-30 fan rig on display at Sun & Fun,...during the mid-1990s???