The Filper Research Beta series of 100A/200A/300/400A variants was an Americantandem rotorhelicopter program. The unusual design was the first helicopter using the "Gyroflex" system and was developed and funded by Filper Research, which was primarily a research unit at the Filper Corporation canning company.
Design and development
In 1958, at his company, the Copperfield Corporation, former Lockheed engineer William F. Orr began work on the "Gyroflex" system of rotor stabilization for a tandem helicopter. After flying a one/fifth-scale model, he continued development on the novelrigid rotor system that used special sinkers at the base of the blades to provide stability. In 1965, the Filper Corporation acquired rights to the Copperfield Corporation as well as the Gyroflex system, providing Orr with stable funding to continue development of the concept. Orr continued his work with J. Ford Johnston as chief engineer, J. Eric Rhodes, chief project engineer, and Irv Culver and John Turner as assistants. The Filper Helicopter was developed as a proof-of-concept testbed that led to the Filper Beta 100A, a tandem rotor design with a two-seat cabin and pylon at the rear, and the engine with the forward pylon in front. This unique arrangement resulted in the pilot and passenger being located at the rear of the helicopter. The fuselage was highly streamlined and the addition of retractable tricycle landing gear allowed for a low drag design. The Filper helicopter incorporated many innovative features, including a conventional control wheel instead of the typical helicopter flight controls, and plush seating in an effort to project the light helicopter as simple and easy to fly. The advantages of a tandem rotor included low noise levels, improved performance compared to other rotor systems and greater stability. The design was intended to ease the transition from fixed-wing to rotor aircraft. This design concept was first tested in a tubular frame test rig that had two pylons with rotors connected by a drive shaft with the engine also located at the extreme front. The single pilot sat at the rear of the open structure.
Operational history
The Beta 100A led to a larger 200A variant that first flew on May 26, 1966, that was intended for commercial use. offered at $20,000 USD. Filper company began production of 32 variants with an anticipated delivery date of 1967. The 200A was followed by a turbine-engined 300 variant as well as a four-seat, stretched Model 400A and 600A. The first Beta 400A with a fuselage stretched by 36 inches, flew on July 13, 1967. The three completed prototypes, Filper Helicopter, Filper Beta 200A and Filper Beta 400A began a testing regime at Livermore Municipal Airport, Livermore, California. All three helicopters crashed, with a fatal accident taking place on November 7, 1967 that occurred when a rotor failed during a high-speed test. The test piloton loan from North American Aviation died in the crash while another test pilot was injured in a second accident. Only three or four of the 32 commercial versions were ever completed, with none of them receiving certification from the Federal Aviation Administration. A further development, the Beta 600A, was cancelled and the helicopter production line was subsequently shut down in 1969. The Filper Research division terminated in the same year with the company concentrating on its manufacture of peach-pitting machinery and its canning operations. The Filper company was absorbed in a buy-out by DiGiorgio Corporation in 1976.
