HP-24 Project

Update 10 April 2003: Layup unveiled, noncertification issues

Well, this morning I unbagged the horizontal stabilizer and peeled the peel ply off of it. It looks good. With just a light touch of sanding, the texture from the peel ply goes away, leaving a smooth and nearly wave-free surface. Next week, I'll do the layup on the lower surface. On that one, I'll try using 5 mil mylar as the release film, which should leave an even smoother surface. My original concern was that the mylar would leave nowhere for the excess resin to go, which would result in a wavy surface caused by uneven resin distribution. I've since been convinced that with beaded polystyrene foam the excess resin will get driven into the foam. Well, I'll give it a try and see how it goes.

Regarding the non-certification issue, a long time ago I wrote in one of these updates that it's not allowed to manufacture non-certificated aircraft here in the us (or rather, not allowed to operate them), but that you were allowed to operate non-certificated imports. It turns out that I was mis-informed when I wrote that. Since that time, I had a chat with George Applebay. He told me that he manufactured Zuni sailplanes without certification, and that operators had no particular trouble registering them as Experimental, Racing or Experimental, Exhibition.

The reason that I mention this issue is that it just came up on rec. aviation.soaring, where a poster quoted my earlier mis-information on that forum. I recognize now that I was wrong, but I'm not going to go back and edit that Update. I'd rather leave the Updates unrevised (or at least substantially so) as a semi-historical record of the HP-24 project.

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page updated 9 April 2003 all text and graphics copyright (c) 2003 HP Aircraft, LLC