Originally Posted by x-surfer
I'd like to bring up the subject of airworthiness because Ed's talk is the foundation of making paper airplanes airworthy. Each real airplane needs to have an airworthiness certificate and to be inspected on a regular basis (either 100 hour or annual inspections, I think) because real planes get banged up too. For example a hard scrape to the wing can change the wing washout and cause a tip stall and incipient spin at low speed, for example.
What an interesting observation. I'd not thought about it, but it is true that I have spent a lot of time making planes that are stable and able to keep their structural integrity while in flight, even when thrown hard. It's different to dart shapes which bend when you hold them, expand when you let go, bend again while flying at different speeds. When I demonstrate the Paperang, I always have to ask the little kids to pick it up by the centre, otherwise they always grab a wingtip and bend it. They seem to have no concept that something I make to millimetre accuracy might work differently if they put a centimetre bend in it!
By the way I've now been in touch with Slater Harrison as a direct result of these conversations, and discovering how my area of investigations over the years have paralleled the walkalong glider developments. For example, I use the flying wing shape because of my hang gliding background, and because I think a really accurate fuselage and tail is too much to expect from paper or other quick-building materials. Walkalong folk use flying wings because they are noticeably less sensitive to pitch perturbations when the 'slope' is brought closer or further away from the glider. I guess there have been maybe 20 or so (Slater's estimate) pioneers working on this sort of thing over the last 30 or so years. Each is discovering post-internet that others have been in the same field. I think we all thought we were at the leading edge, but it turns out there have been so many different leading edges!