In 1960 the American company "Filper
Research" managed by William Orr built an unusual helicopter. It was
equipped with "Gyro Flex" system of rotors. The novelty was in using
special sinkers for rotors trimming supported at the base of the
blades. This concept was first tested on a Filper Helicopter that had
two pylons with rotors connected by a bar and the pilot sitting on top.
The engine was also located there.
After the prototype, a
commercial type of Filper Beta was built. Its design was based on the
tandem system with an engine in the front pylon and a two-seat cabin in
the back. The funny part was that the pilot sat too far from the nose
Filper Beta 200 flew on May 26, 1966. The company designers planned to
build several modifications of this helicopter, both two-seat (Model
200A and 300) and four-seat (Model 400A and 600A). The fuselage in the
four-seat model was extended 0.9m. The first four-seat helicopter
Filper Beta 400A flew on July 13, 1967.
Beta helicopters were
equipped with different engines. Some had Continental IO 360-E with
155kW capacity (Model200A), others had Allison 250-S18 (Model 300) and
Continental IO-520 with 185 kW capacity (Model 400A) engines. The
engine type in Model 600-A was unknown.
records say that 32 Beta helicopters were built: two Model 100A, 29
Model 400A and one Model 600A but It is doubtful that all of them were
2 plus jump seat
In 1969 Filper company closed.
Gross Weight: 1700 lbs.
Empty Weight: 1000 lbs.
Useful Load: 700 lbs.
Powerplant: 6 cyl. fuel inj. Continental IO-360E 210 hp
Fuel Capacity 42 Gal.
Disc Loading: 2.6 lbs./ sq.ft.
Power Loading: 8.0 lbs./ hp