Netters; Someone asked the question about the possibility or benefit of fairing the tailwheel. I haven't seen any takers on that, so I thought I'd throw out something I just read in the Fall '03 issue of "To Fly" last night, about a Thorp T-18 that a gent built and documented the performance changes due to fairings, cowlings, and etc. since the Thorp was originally conceived and designed as an open-cockpit airplane with the engine cylinders hanging out in the breeze and unfaired Wittman-style spring gear.
The Thorp is similar to the KR in a few ways, but that's not the point. What is of interest is the magnitude of the gain for each modification or improvement. Among other things, the builder said that each of the following gained 2 to 4 MPH in top speed: adding wheel pants, fairing the pant/landing gear leg junction, and fairing the tailwheel spring. He did not mention a "pant" for the tailwheel itself. He also said that down-pointing exhaust stacks cost him 3 MPH (ergo, Mark Langford's approach of turning them into the slipstream. Also a potential for some thrust gain). He figured that with the fairings and streamlining he did on his airplane, every 10 MPH gain in top speed due to drag reduction equated to 25 fewer HP required (for the Thorp)... with the associated weight, complexity, cost, fuel consumption, and the rest of it. And of course the rate of climb has the same gains and losses as top speed. In passing, and since it's Friday (in Texas, anyway), here's something I didn't know... also from "To Fly". Art Chester, the racer who built the "Goon", "Jeep", and "Swee' Pea" back in the pre-WWII days, worked for North American and was on the P-51 design team. He is responsible for the design and construction of the innovative box-beam bed mount for the Allison engine in the P-51. Also interestingly, the British specs for the airplane (we made some for them) were for a pilot size of 5'-10" and 145 lbs., which were Art's exact measurements. So he was the "test dummy" for fitting the cockpit of the prototype to the British specs and everything was made to fit him. The longer I live, the more I learn! Oscar Zuniga San Antonio, TX mailto: taildr...@hotmail.com website at http://www.flysquirrel.net _________________________________________________________________ Cheer a special someone with a fun Halloween eCard from American Greetings! Go to http://www.msn.americangreetings.com/index_msn.pd?source=msne134
