Here's something I posted March 7th of this year on the KR1B that might help. -----------------------
I guess it's obvious from my recent posts that I've been thinking about the KR1-B Motorglider. One of the things I asked my FSDO rep a few weeks ago was "what defines whether an aircraft is a motorglider or not?". He didn't know, but when I offered up the formula that I mentioned a few weeks ago (ratio of empty weight divided by wingspan squared < .62) he said he'd never seen it, but it sounded good to him. He also said "if the plans maker calls it a motorglider, that just about clinches it". Keep in mind that the whole point of this exercise was the fact that you don't have to have a medical to fly a "powered glider", which is exactly what the KR1-B Motorglider is, by definition. What got me going on this was an article about the new Sonex motorglider in a recent magazine, where the author says he built it purely as an endrun around the medical, and it worked! Dana (or somebody) mentioned that some kind of paperwork would almost certainly be required. I'd think that somebody that knows they can't get a medical, but dearly wants to fly, would have the determination to be the first to prove the point by doing whatever it takes to get a KR1-B signed off as a motorglider. William Wynne mentioned yesterday that two British builders had become the first homebuilders (or even manufacturers) to get approval to fly a plane with only one set of spark plugs in their country. They did the research, proved that it was being done elsewhere, provided the necessary paperwork, and accomplished their mission. I think the KR1-B could be done the same way, although there may not be a problem at all with it, given the fact that one has already been built and flown, and it was 30 years ago. Going by what my FSDO said, I'll bet I could build one and fly it with no medical, no questions asked, but you definitely ought to check with your FSDO first. So, given the above info, I ordered a set of KR1-B plans myself last month, and got them yesterday. They are $35, plus $5 shipping from Rand Robinson. They include an instruction sheet and five large drawings. I've always wondered about the details, and found precious little information about them, and nobody willing to share much (more than a few words at a time). I also bought a set of never-used KR1 plans from Royce in South Africa, so I may be one of the few clowns that owns a full set of KR plans. My 1-B plans are number 411, which is, oddly enough, the number for "information". Here's the deal. A standard KR1 is where you start. You can buy one already built, and just build a new set of wings for it. It's probably based on a 1600cc VW engine, but an 1835cc is practically the same weight. Spars and RAF48 airfoil are the same as the KR1's stub wings, so you don't have to change a thing on the KR1 except add a flap handle if it doesn't have one. The new wings have an 8" transition from the stub wings' RAF48 to the -B's GA(W)-1 airfoil, and spars that are about 120" long, but thicker front to back. Construction is pretty much the same, with the exception of huge flaps and ailerons that look a lot like the ones on my KR2S, all located in the outer wings. Aileron actuation is by the stock bellcrank system, and then an "extender" pushrod running out to the start of the ailerons, and a new bellcrank out there. Flap extension is almost exactly like what I'm doing, except there's also a piano hinge added between the big hinge brackets. The neatest thing about the KR1-B wing is the flaps. They are a combination of flaps and spoilers, made possible by a very simple arrangement of the flap hinge pivot line. It's hard to explain, but the hinge line is at the bottom, and the gap to the top of the airfoil surface extends way forward, so that when the flaps go down, the top of the flap sticks up into the slipstream, and spoils the lift. Sort of like an upside down Frise aileron, but with a sharp edge rather than a rounded nose. I just love this concept, and it's so easy to do! Talk about glide control! See the info sheet at http://www.krnet.org/kr1binfo1.pdf for a few more details, and note the 38 mph stall speed (with flaps). And wouldn't that get you into the Sport Pilot category (yes, we've beat the Sport Pilot/medical horse already)? It should be noted that if you use the formula mentioned, you must keep the plane as light as humanly possible to keep it under .62, and in fact, I'd add a few more inches to the span for insurance. I asked Jeannette why she didn't even mention the KR1-B on her web page, and she said it was because it lived in a bit of a gray area and she wasn't sure if the FAA would look "askance" at somebody building one as a medical dodger. Judging from why my FSDO told me, that wouldn't be a problem for ME. I would think that a call to your FSDO would answer that question for YOU. So, you guys that are worried about your medicals, start looking for a used KR1 and build yourself some wings! Mark Langford, Huntsville, AL N56ML at hiwaay.net see KR2S project N56ML at http://home.hiwaay.net/~langford
