The Fly Baby Story - Oshkosh 365

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(Photo by Bowers) All the tooling needed to assemble the fuselage sides— a flat work area and some notched two-by-fours. There are only two scarfed plywood splices in the whole airplane —visible halfway toward the tail. the average chord, or span squared divided by wing area) increases, induced drag, especially at the low speed range, is decreased. Racers, which don't care about easy landing, have ratios as low as 3 for good high-speed flight but the safe-and-slow jobs want higher ratios, at least over 6. For sailplanes, the A.R. alone is a pretty good index of performance, with a high for the super-dupers of 24 to get 40-to-l glide and 16-18 the best structural compromise. There just aren't any in production any more with aspect ratios under 10. In modern airplanes, the Piper PA-15/17 "Vagabond" with A.R. 5.8 and a span of 27 ft. just couldn't compare with the old J-3 "Cub" which had 35 ft. and an A.R. of 7, and the four-place "Vagabond" developments, the "Clipper" and the "Pacer" never really arrived until the horsepower was upped from the original 115 to an eventual 160. As a result of all this, the new design ended up with a span of 28 ft., an A.R. of 6.5, 120 sq. ft. of wing area, and a good long tail moment arm. Another distinctive fe; ture of the Story was the simple wire bracing of the two-spar wings to the upper longerons and to a rigid larding gear. Where the Story, in common with the Ryan ST of 1934 and the Boeing P-26 of 1932, ran the lower View into the cockpit showing the finished forward spar bulkhead and the hydraulic brake master cylinder mounting. Note the inboard plywood covering over the double bottom longerons and the forward bay. The diagonals carry landing gear loads in the forward bays but only serve to stiffen the plywood skin in the bays behind the cockpit. Dural angles in forward corners transmit engine mount loads into the fuselage sides. Floorboards rest on top of the double longeron structure. (Photo by Bowers) (Photo by Bowers) Two fuselage sides—one with the plywood skin and one with the temporary gussets. Note the "double" bottom longerons. Forward upright is birch or oak; other truss members are spruce. (Photo by Bowers) Interior of the fuselage looking toward the nose from behind the cockpit, showing the corner bows that stiffen the two wing carry-through bulkheads. Diagonal in front is strictly temporary. wires to auxiliary structure behind the wheels, the new design followed the even earlier style of the Howard "Pete", Heath "Baby Bullet", and the earlier Curtiss Military Racers by cleaning up the whole under carriage, using a straight-across axle, and attaching the wires right to the axle ends. Consideration was given to using struts above the wings instead of wires, as on the Stits "Playboy", but the longer span meant that the strut-wing intersection angle would be very acute and produce a big interference problem, causing high drag and a significant loss of lift. It's good to be able to learn by the experience of others, and since Fred Sindlinger of Seattle had considerable trouble with his short-span original design in this area, it was decided to eliminate the problem by using wires. This decision was backed up by some of the design articles appearing in SPORT AVIA- TION and the EAA manuals at the time and the fact that Vs in. 1 x 19 stranded stainless steel wire, which tests 2,100 Ibs., is a lot cheaper than streamlined steel tubing. A couple of features that it shared with the 1940 gas model were the laminated wood wing tip bow construction and tip shape, and the vertical tail shape with small underfin. These had practically become a Bowers trademark, having been used on all my gas models from 1937 to 1949, when I built my last one. With the new design pretty well firmed up and the EAA contest now under way, we decided that Ron would build the new one and enter it as "Fly Baby II" while I built the original 1951 design as "Fly Baby I". Ron got started first, and had both fuselage side frames built, covered with plywood, and joined together when he got a remote-base assignment and had to give it up. Since (Continued on next pog«) SPORT AVIATION 5
"FLY BABY" . . . (Continued from page 5) (Photo by Bowers) Tail surfaces are wire braced and wooden-leg landing gear is rigid. Fuselage plywood is covered with fabric at time ship is covered. I hadn't started mine, I did some serious thinking about the contest requirements, especially where they stressed simplicity of construction, easy flying, and low cost. The "II" had it all over the "I" here, so I decided it would be the best one for the contest and bought Ron's fuselage for what cost he had in it. Since the Cantilever job was still on the drawing board, there was no point in calling the existing piece of construction "Fly Baby II", so it became plain "Fly Baby", later "Fly Baby "I" to provide a more definite designation for FAA paperwork. Later on, when it was decided to use three different wing arrangements for versatility, the designation was expanded to "Fly Baby 1A" for the low-wing design, "IB" for the same fuselage with a new set of biplane wings, and "1C" for a strut-braced parasol monoplane wing fitted to the biplane center section. While the original design had been worked up for an 85 hp engine, this was no longer available, so 65 was chosen for the "Fly Baby I" because it was more generally available and cost less. This was replaced by a Continental A-75, the A-65 converted, under rather unusual circumstances. George Loeffers of Seattle had bought a 65 hp Taylorcraft that needed recover and an engine overhaul. He decided to convert to 75 hp in the process, but found out after the job was done that his ship couldn't take a 75, having been converted up from 50 hp originally. So, since he had a 75 he couldn't use and I had a majored 65 that he needed, we traded for the cost of his conversion. For all practical purposes, though, this engine operated as a 65 while in the ship because I used a 65 hp metal prop on it and didn't want to cut it down from its present 74 in. diameter to the 69 in. it was supposed to be for the 75, which picks up most of the extra 10 hp by turning a smaller prop 200 rpm more than the 65. Actually, the ship was designed to take up to 85 hp, but I figured that there was no point in going beyond that. As work progressed, I found that one of the biggest problems was shooting down the suggestions of all the well-meaning visitors who kept trying to improve it to death by suggesting that "You can get another 5 mph by cleaning this up", and "Why don't you ...?", and so on. I had problems with myself in this department, too. It took real will power to keep in mind that this was a ship for beginners and resist the temptation to add features that I would want for my own personal ship. Well, as practically everyone finds out sooner or later on such projects, things went much more slowly 6 DECEMBER 1962 than expected. The contest deadline of August, 1960, got near; "Fly Baby" was a long way from completion. Fortunately, volunteer help from George and Dave Trepus, who worked at Boeing, became available, and one of the model building kids in the neighborhood, 12-yearold Dale Weir, and a couple of high school kids, Jack Davis and Tony Honsburger, made themselves fixtures in the shop and soon became indispensable. With only a couple of months to go, the panic button got pushed hard and craftsmanship went out the window. For the last couple of weeks, everyone I could drag into the shop was put to work, including some local FAA inspectors. Jim Clark of West Coast Airlines, owner of one of the Storys, handled the powerplant problems and Fxi Rudolph of G.E. was the paint department. A word about the covering and coloring — I had intended to use the colors of the prototype Boeing Jet Transport, yellow and brown with white trim and wanted it to be nitrate dope over the Sears-Roebuck Dacron Polyester Taffeta ($1.37 a yard), but Rex, who is an enamel enthusiast, talked me into using automotive enamel for the finish. The closest the auto supply store came to the desired color was "National School Bus Yellow", so this is what we used. The shade "Cordovan Brown" that looked good on the color chart turned out to be a metallic maroon (Photo by Bowers) Tail surfaces are built without jigs. Elevattor spars take torsion loads so are of box construction; stabilizer spar is C-section. Note that end ribs are double and boxed with plywood to resist doped fabric tension. Ribs are V* in. plywood with V* in. sq. cap strips and leading edges are covered with .016 in. hardware store aluminum. on the airplane, but didn't look at all bad. Rudy really threw the stuff on as time ran out, and we didn't bother with the white trim. Art Schultz of the Boeing art department took a short cut on the white fuselage numbers and outlined them with black 1/16 in. chart tape sealed with clear plastic spray. This tape held up fine for over a year and a half in the weather. With only a week to go before the date of departure for Rockford, panic really went into high gear. Other contestants seemed to be having the same problems, for the judges cut the required 50 hrs. of flight time down to 25, and then took to phoning Hie various ones to find out if they'd even have their ships finished in time. There was serious consideration given to postponing for another year, but at the last minute it was decided to have it as scheduled. The test hop for "Fly Baby" was scheduled for Wednesday, July 27, 1960. Needless to say, work carried right through from the time I got home from Boeing Monday night, all through Tuesday when I took sick leave, and all through the night and into Wednesday morning when we loaded the ship on a glider trailer and hauled it to Thun Field, at Puyallup, Wash. This was 35 miles away,
Page 1: (Photo by Bowers) "Fly Baby" set up
Page 5 and 6: "FLY BABY" . . . (Continued from pr
Page 11 and 12: "FLY BABY" . . . (Continued from pa

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