Sport Aviation 9/83 pp 55-59 Dragonfly: From Beginning To Pre-Fab By Rex Taylor (EAA 87893) President, Viking Aircraft RR 1, Box IOOOV Eloy, AZ 85231 THE DRAGONFLY HAS been on the homebuilt scene for 3 years and in that time has become the 5th most popular homebuilt aircraft design, according to a survey by the Dayton, Ohio EAA Chapter recently. The best representative builder-built aircraft of the top ten homebuilts has been selected to receive the Dayton Chapter's Wright Brothers Memorial Award. There were several beautifully done Dragonflys to select from, even though the plans have only been available for 2 1/2 years, but the winner was Terry Nichols of Ventura, CA. Those 3 years of evolution in the Dragonfly design have been very hectic. Designer Bob Walters had flown the Dragonfly to Oshkosh 1980 from California, thinking that most of the hard work was behind him. The instant demand for plans, even before the show opened and the next 7 days of talking to literally thousands of people asking hundreds of questions, was a glimpse of the future for Bob and his wife, Ching. Dragonfly received the 1980 "Best New Design" award and Bob returned home to work every waking hour for the next 4 months to get the plans ready for sale. The first plans were released in October 1980, bringing in the first income from the design. Bob had not accepted any money from anyone until plans were ready to use. His concept of the Dragonfly design and his market objectives were very interesting. Some of his marketing ideas have survived the intervening 3 years and some others have undergone drastic changes. The changes and the reasons are indicative of the changing nature of our great hobby and an indicator, I believe, of what the future holds in store for homebuilders. Design History The Dragonfly was designed to provide the best possible performance on a Volkswagen engine. The design objectives specified an aircraft that could be built at low cost, yet have high cruising speed, low take off and landing speeds and be easy for a low time pilot to fly. Sounds like a big order, doesn't it? To achieve the high cruising speed designer Bob Walters realized that only a super clean aerodynamic design would do. The equal span canard layout was chosen because both the canard and the wing lift. There are no downloads such as the elevator imposes on a conventional aircraft, thus the total lift generated is useable and results in greater efficiency. A relatively high aspect ratio was chosen for even greater efficiency in the airspeed and altitude range that Dragonfly was designed for. Airfoil selection was of great importance and was carefully plotted against the mission profile anticipated for the design. The G.U. (Glasgow University) series of airfoils commonly used on canard designs would work, but Bob's computer studies indicated that significant improvement could be obtained in delaying the onset and abruptness of stall condition. By thinning the section slightly and moving the point of maximum thickness aft better characteristics at low speed and high angles of attack were obtained. Calculating the weight of 2 FAA sized people (175 pounds each) and baggage of 50 pounds plus the weight of the engine, airframe, instruments, radios, etc., a planned gross weight was obtained. Armed with this weight, the size of the aircraft was adjusted to provide plenty of wing area to obtain a light wing loading, assuring slow takeoff and landing speeds, plus good altitude capability and rate of climb. An aircraft must be more than just efficient to satisfy the discriminating builder in these times. It must also be comfortable to sit in, have all controls and properly placed for use by the pilot, and most of all, the aircraft must be pleasing to the eye. Side by side seating was chosen because the center of gravity shift between minimum and maximum allowable weights would be negligible. Pilot and passenger can maintain conversation at a normal level and a greater degree of sharing the joys of flight is possible as compared to tandem seating. Dragonfly's cockpit was designed to the best anthropometric data available, assuring that such critical to creature comfort items as leg room, seat back angle and support, head room, and vision were not overlooked. The pilot's need for mobility within the cockpit was considered essential to make long cross country flights a joy rather than an ordeal. A dual set of controls was felt to be necessary to allow the Dragonfly piloting experience to be shared with the passenger. The dual controls also have allowed some "limited time" or "no flight experience" builders to gain their license in their own Dragonfly's. This is a real savings in training dollars and quite legal by FAA rules. Fuel tank capacity was calculated utilizing the engines 75% power consumption figures to provide a 500 mile useful range with a generous reserve for safety's sake. At lower power settings the range can be significantly increased. Dragonfly recently completed the 1983 CAFE 400 race, flying 400 miles on 8.6 gallons of fuel at an average speed of 128.03 miles per hour for a fantastic 45.08 miles per gallon! Dragonfly finished second in the 2-place experimental category behind a VariEze. That's real efficiency!! In fact, Dragonfly achieved the best mpg score of any aircraft and won the Tom Jewett Memorial Award. Had we chosen to run the race at higher speed, of course miles per gallon would have been less. Dragonfly was designed with considerable attention to frontal area. Every effort possible was made to minimize "flat plate area" and Dragonfly's sleek lines reflect this concern. The engine cowling behind the propeller can greatly reduce propeller efficiency if it's big and bulky. Dragonfly's engine is very tightly cowled to insure that the least possible amount of our precious thrust is wasted on frontal area. The engine cowl and its internal baffling were also designed to provide excellent engine cooling particularly in take off and climb modes where the engine must produce maximum power, but air flow is reduced because of climb speeds. Another factor to be considered here was optimizing cooling drag which accounts for a significant portion of the total drag equation. The internal bafffling was the result of cooperation between designer Bob Walters and HAPI Engines'engineering staff, giving low drag and high cooling efficiency. This attention to the small details has been carried out throughout the design of Dragonfly. Good overall performance is the sum of the many small gains that can be achieved by a consistent "no compromise" design philosophy insisting that each part function at its very best. About the Designer Bob Walters, Dragonfly's designer, is a multi talented individual who strives for perfection in everything he does. Bob learned to fly at an early age. Fresh out of college he joined the Navy to be trained as a fighter pilot. Bob served some of his time engaged in low level combat in Vietnam. He left the Navy to work for Grumman Aerospace, spending 4 years in Iran teaching the Iranians to fly F-14 jet fighters. Returning to the United States, Bob went to work for TWA as a flight engineer. In his leisure time over the next few years he built a "Duster" sailplane in which both he and his wife "Ching" competed in Southern California Soaring Contests. Bob was one of the early VariEze builders and became involved in the composite revolution that Burt Rutan's designs brought about. After the VariEze, Bob helped a friend build the little Onan powered Quickie, and became enchanted by the possibilities apparent in the equal span canard arrangement. Bob had an aeronautical engineering degree and was eager to put his talent and training to the test, so he set out to design a high speed, low cost, easy to build and fly aircraft. By the fall of 1979 most of the preliminary design studies and drawings were in order and construction was started. The prototype Dragonfly was completed and ready for initial flight tests in May 1980. Bob's piloting and engineering background were a great asset in the flight test months of May and June 1980. On July 4, 1980, Dragonfly was publicly shown for the first time, attending a fly-in at Brown Field, San Diego, California and was an immediate success. It is inevitable that Dragonfly is compared with the Q2. The question is often asked, "Who copied who?" The truth is that both Bob Walters, Dragonfly's designer, and Garry LeGare, Q2's designer, had been influenced by the Quickie design and each had decided to design a 2-place Volkswagen powered aircraft. Both designers were completely unaware of the other's existence or design efforts. The design concepts of the two aircraft are quite dissimilar, so much so that the suggestion that one "copied" the other are ridiculous, if the plan forms and specifications are compared. About Viking Aircraft When Dragonfly became an instant hit at Oshkosh 1980, Bob was suddenly in the plans and information business. He and his wife found the next two years to be filled with 12 hour working days, 7 day working weeks and a seemingly endless backlog of things that needed doing that there wasn't time enough for. One of the very first major changes that the builders wanted was an engine equipped with a starter and dual ignition. The prototype was equipped with a 1600cc VW engine and a 10 amp alternator to power up the electrical equipment aboard, but little else. Bob purchased one of our HAPI Model 60-2 DM engines, an 1835cc producing 60 hp at 3200 rpm. The starter,20 amp alternator, mixture control and dual ignition are standard equipment. Cruise speed went up about 10 mph and the rate of climb was much better. Though not initially enchanted with the additional 15 pounds of weight gain over the "plain Jane" version, Bob grew to love the convenience of the starter. I don't know of any customer ever opting for the simple hand start engine since. Further, some of the parts are difficult and time consuming for the builder to make, such as the canopy and molded fiberglass cowl. Bob had constructed a form for molding the Dragonfly canopy that provided the exact shape necessary for the canopy as a part of the fuselage, rather than using an off the shelf free blown "bubble" type canopy. Consequently, the very efficient shape of the fuselage has contributed to the low drag coefficient of Dragonfly. The pre-molded canopy and fiberglass cowling were made available to the builders, plus a few items such as tailwheel springs, (a fiberglass pultruded rod), tailwheels and a few hard-to-find hardware items. Bob also supplied carbon fiber to the initial builders as Dragonfly pioneered the use of carbon fiber in homebuilts and the material wasn't readily available everywhere. Bob and Ching's life was becoming much more complicated by the day, with days and nights filled with answering letters from prospective builders, providing builders support by phone and more letters, plus writing advertising materials. He was also writing a quarterly newsletter amounting to usually 8 pages of closely spaced material and even found time to write two articles for SPORT AVIATION, one on moldless construction, then an excellent article on finishing composite aircraft that has become the "standard" method of achieving a show quality finish for builders of all kinds of composite aircraft. Every weekend was spent either at Oceanside Airport showing the Dragonfly to the interested or Bob and Ching were off to a fly-in, with Ching driving the van with camping gear, brochures, plans and a few cold beers to unwind with in the late afternoon. Bob came to the decision before Oshkosh 1982 that more people were an absolute necessity if Viking Aircraft was to keep up with plan sales, builders support, editing newsletters, attending fly-ins, answering dozens of phone calls and letters per day and all of the other many tasks that had to be done. Being far more interested in having the freedom to design again than being a businessman Bob offered the Dragonfly design and Viking Aircraft Corporation to the Taylor family. Bob felt that with our already existing staff producing HAPI engines and Posa carburetors plus supplying a myriad of parts to the homebuilder, that we could handle the customers needs well. Since acquiring Viking, we have expanded the scope and direction of the design greatly. Bob had envisioned the typical Dragonfly builder as wanting a low cost airplane and being willing to build virtually every part from raw materials to keep the price down. We soon found that, in fact, most builders wanted all the prefabrication possible and were willing to pay for it. We felt it imperative to continue to serve the builder who wants to build every part himself, including the engine, whether his desire is to save money or simply satisfy his own whim to build every part. We also knew that to satisfy the builder who wants to get into the air in minimum time, we would have to supply a very high degree of prefabrication. Getting into the prefab business posed a terrific challenge. To create the kind of end result we envisioned would require considerable technical talent, plus lots of machinery and tooling. We carefully selected vendors, each a specialist in his own field with a track record of good service to the homebuilder. The key vendor in the plan would supply the prefabricated molded parts. We wanted to offer a really complete set of molded parts that could be put together almost like a plastic model aircraft kit. We wanted to offer the prefab in such a manner that the builder could purchase the parts on an as needed basis, rather than signing up for a complete kit. This plan also allows the "scratch" builder to purchase some of those prefab items that may be difficult for him to fabricate. The plan has another benefit of saving the builder the cost of us buying from the vendors, warehousing and reselling to them, which, of course, wouldn't add a bit to the quality of the part. TASK Research, Inc. of Santa Paula, CA came highly recommended in four areas: experience, expertise in solving difficult problems, quality of finished parts and delivery. TASK accepted our challenge to help us make Dragonfly the best kit aircraft on the market in December 1982. After 6 months of design and tooling TASK is producing what we believe you will agree are the finest premolded parts yet. Jim Kern of TASK has developed complex tooling that produces Dragonfly parts, each of which can be triaL fitted through a system of lap joints. Cleco clamped together just like a metal aircraft, this allows the fuselage structure to be trail assembled before bonding anything! The method is very quick and simple and allows adjustments to be made easily to assure that final assembly and bonding will be accurate. The outside seams on Dragonfly's prefab fuselage have depressed areas on both sides of the join line so that outside bias tapes lay slightly below the finished surfaces. After taping, the joined areas are simply squeegeed over with a mixture of micro balloons and epoxy, sanded and you're ready for paint. No difficult feather edging to cover a joint is required, saving many man hours of work. The prefabricated Dragonfly has yet another advantage: it's approximately 50 pounds lighter than a plansbuilt, wet layup structure. This is due to the use of pre-preg glass cloth, vacuum bagging and thermocuring, resulting in parts that are lighter, stronger and have a smooth molded exterior surface that will not need a lot of heavy fillers and primers to achieve a paint ready surface. The weight savings in the airframe will increase payload capability without adding to gross weight. TASK is now delivering prefab "Snap" Dragonflys and an overseas distributorship network is in place to serve foreign customers. Ken Brock Manufacturing Company of Stanton, CA has been the source of high quality system components for several top designs for years, among them the Thorp T-18, Marquart Charger, VariEze and the Long-EZ. Ken has a large punch press shop, with his own machine shop to fabricate dies, plus certified welders and metal finishing departments. If you want the best, you go to Ken; it's that simple. Ken is now building all the metal hardware for Dragonfly and sells them directly to the builder, either in complete sets or any part separately. HAPI Engines supplies the powerplant and all its related items, such as props, spinners, mounts and exhaust systems. They also stock engine controls, engine and flight instruments. Wicks Aircraft Supply provides all the airframe materials for the scratch builder, as well as stocking some of the pre-fab parts. The builder has the option of building the aircraft any way he wants, using as much or as little of the pre-fab as he chooses, without being locked in to contracts obligating him to anything. Other vendors too numerous to mention here are on board for specialized parts. A complete list of materials and vendors is supplied with the plans. Builders are notified through the quarterly newsletter of new products or services for Dragonfly. The newsletter also serves as the medium to notify builders of any plans changes or corrections. We have continued with the builder support Bob started, and have found surprisingly little necessary, which argues well for the quality job Bob did on the plans and 100,000 word construction manual. Bob has been retained on a consulting engineering basis to get us out of trouble when we have a problem or question requiring his expertise. Most of the problems, though, are repetitive in nature and once we have encountered it and contacted Bob, we then have the knowledge to help the next time it appears. We have seen builder's groups form in several locations around the country, having regular meetings and sharing the triumphs and tribulations that are part of building an aircraft. These groups offer the builder the chance to draw on the knowledge and experience of others, plus share tooling and labor on some areas of construction. I have had the opportunity to speak to several of these builders groups and am pleased to see most of the builder's wives are with them. We have found that the completion rate on any homebuilt project is greatest when the wife is involved and enthusiastic about the project. One of the first Dragonflys to fly was built by Terry and Joan Nichols of Ventura, CA and it would be difficult to determine just which of them did the most work on the aircraft. Their's is finished and flying great so they now have too much time on their hands. What to do? Why, they're starting a new pre-fab Dragonfly, of course! There doesn't seem to be any typical Dragonfly pilot type as yet. Most Dragonflyers have had the usual light aircraft, no taildragger experience background, but a couple come with thousands of hours in just about anything that flies. Bob Violet of Delphos, Ohio, finished his Dragonfly and got two of his total of ten hours of dual instruction in it. He was then soloed in a Cessna 150 by his instructor, Ray Venekotter. With a grand total of twelve hours piloting experience, Bob soloed his Dragonfly and now has over forty hours in it without incident. My own experiences in Dragonfly have been described in SPORTAVIATION. It's a very easy aircraft to fly, but does have a couple of quirks that are probably found only in canard tip mounted conventional landing gear. I advise anyone building a Dragonfly to come to Viking and get some free dual before test flying. Just as most nosewheel pilots couldn't handle an old docile Cessna 140 without a bit of dual, this type of aircraft does require proper landing technique to keep everything from getting exciting. I find it usually takes about five take offs and landings when I'm coaching a builder before he's mastered the aircraft. After that, all he needs is practice. I have talked to several builders and prepared them for that "first flight" verbally, and most of them have had no problems, but I believe that nothing is as good as hands on experience, if only to calm the nerves somewhat. Bob's dream of a simple high speed cross country aircraft that could be built for $5500.00 is still achievable today by careful shopping and a labor intensive building program, but the evolution into a completely prefabricated aircraft for roughly $5000.00 more has surprised Bob more than anyone. When he set about to design the Dragonfly, the average time to complete an aircraft was probably 5 years. Today's builder expects to be able to build the aircraft in a matter of months, though, in reality, few are built in under a year. From the initial estimated 1200 man hours involved in Dragonfly construction, availability of prefabrication has reduced that figure to only 500, at an increase in cost of only $5000.00. Approximately $2000.00 of this is in the engine compartment in the form of options such as starter, alternator, dual ignition and other extras that the Plain Jane model envisioned by Bob didn't have. The other $3000.00 goes for the 700 hours of labor saved and works out at $4.29 per hour, amazing when you consider that an aircraft repair shop usually charges at least $25.00 per shop hour. We have estimated that about 24 people are working full time on the Dragonfly now, counting both ours and vendor personnel busy with Dragonfly production. The National Association of Sport Aircraft Designers (NASAD) awarded the Dragonfly design and plans their seal of approval early this year, an honor formerly held only by Burt Rutan's Long-EZ and VariEze in composite construction designs. I personally wasn't quite sure whether I liked this "funny looking airplane" or not the first time I saw it. I've grown to love it and after over 200 hours of Dragonfly flight time in the past year, I believe you would have to go far to find a better VW powered aircraft than the Dragonfly. Captions: (Photo Courtesy Viking Aircraft) Terry Nichols' Dragonfly, with Rex Taylor in the prototype on his wing. All exterior surfaces on the Dragonfly except the wing, canard and fin are molded in these 16 molds. Several more molds are required for internal parts such as the tank and control consoles. Dave Steinback of Woodstock, Ontario, Caneda is flying now. Dave's Axis Aviation is the Canadian agent for Viking Aircraft, Ltd. Courtney Bryan of Dayton Ohio attended Sun "N Fun 83 with his Dragonfly, averaging 150 to 170 mph T.A.S. on the flight. Bob Violet of Delphos Ohio built this Dragunfly and soloed it with only 12 hours time, 10 dual and 2 solo hours! He's accumulated another 40 hours in his Dragonfly now.