VANGRUNSVEN RV-4 – N14RV
Dick VanGrunsven’s definition of sport flying included frolicking about the sky in a plane well endowed for three dimensional flight, capable of virtually becoming an extension of a pilot’s will and limbs. In this light, Dick designed the RV-3. Shortly after the RV-3’s appearance on the market, demands for a two place version came rolling in, though it wasn’t until after he got married that Dick got serious about the project.
Dick developed seven goals for the RV-4, including good short field performance, comparable or better pilot visibility than the RV-3, high cruise speed, and structural integrity, performance, and controllability for good aerobatics. Dick also wanted the RV-4 to be capable of carrying two 180 pound people of 6 foot 2 inch height, demonstrate safe flight qualities, and be enjoyable to fly. The RV-4 also had to be capable of being built with relative ease and economy by an average homebuilder.
Since the RV-3 met all except the two place stipulation, it was logical to simply modify the RV-3. After a little research and designing, Dick found that to carry two people he needed to widen the fuselage, increase the tail surfaces, expand wing area, and modify the landing gear to accommodate the extra weight. All the changes added up to an entirely new airplane, not just an RV-3 modification.
Actual construction of the RV-4 began in the fall of 1975 and wasn’t completed until August of 1979. The RV-4 was constructed of all stressed skin aluminum and featured “Wittman” landing gear legs. The fuel tanks were located in the leading edge of the wings in “wet tanks.” The plane was powered by a 150 hp Lycoming engine.
The first flight of the RV-4 was on August 21, 1979, and, while there were still some kinks to work out, the two place airplane performed nicely. Testing continued through the fall of 1979, ranging from basic tests to performance and aerobatic tests. The aircraft demonstrated structural integrity, performance margins, and controllability required for good aerobatics. RV-4 aerobatics were designed to be fun, graceful, and beautiful.
Testing was completed in early 1980 and Dick began working on the construction drawings and production tooling for kits. He was very pleased with his RV-4, claiming that the two place airplane exceeded his expectations in nearly all ways. The RV-4’s overall performance with the 150 hp engine was about the same as that of a one place 125 hp RV-3.
Dick VanGrunsven and his wife Diane enjoyed the prototype RV-4 for many years. In 1997, they donated it to the EAA AirVenture Museum.
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