Volmer VJ-23 Swingwing
Designed in the early 1970s by Volmer Jensen, the Swingwing is essentially a powered hang glider. Empty weight without engine is 100 pounds, and the gross weight is 300 pounds. The Swingwing is built from aircraft plywood, spruce, steel tubing and fabric covering. Aluminum and metal tubes for the structure, and wood for the wing. Control surfaces include ailerons, elevators and rudder.
Designed by Volmer Jensen and Irv Culver, its cost Jensen roughly $400 in supply. The total construction time is estimated at three months of construction in free time. Culver is an aerodynamic engineer who designed the profile of the VJ 23 SwingWing and made the fatigue study.
The cantilever wing has a relative thickness of 16%, thus eliminating the reinforcement by cables or struts. The disassembled craft is designed to be assembled in 30 minutes.
The wing is constructed in two parts of 4.88 meters and able to be assembled with three bolts. The wings, which weigh 15 kilos each, with a limit load factor of 2G and an ultimate load factor of 3G. The leading edge of the wing is made with a 1mm backing, and the leading edge ribs are 1cm thick marine plywood, with spruce for the ribs of the tail unit, and rods for the spar of the wing. Jensen does not use epoxy for the VJ23, preferring white glue that he has been trusted for years. The wings and tails are covered with Ceconite, a light fabric of 1.8oz / sqrd. The tail boom is an aluminum tube of diameter 10 cm and 4m long.
Apply the fabric without stretching it, then apply a coating to ensure waterproofing. The fabric can then be stretched with an iron.
What distinguishes SwingWing is its unusual ability to stay in the air. With a modest wind of about 30 km / h, the pilot takes off in less than two or three steps and then flies as long as he can stay in the ascending part. For short-term flights, the pilot is suspended by leggings, but a seat harness can be used with a seat for longer flights.
During a demonstration of SwingWing, Jensen remained in the air for more than 40 minutes, flying along and before a dune at an altitude of 35 ft (10 m) with a length of 300 yards. The 23° slope seemed to have an excellent performance for dynamic flight. The speed of cruising is between 25 and 40 km / h. The landing takes place in one or two steps.
Although the VJ23 prototype carries Federal Aviation Administration registration number N474VJ, registration is not required.
In 1978, David Cook became the first hang glider pilot to fly over the English Channel in one hour, flying at an altitude of 1000 feet in a powered Swingwing.
A motorized version has been built as the VJ-23E.
VJ-23E Test flight No7 Pilot A.Rudelis
The VJ 23 was never built factory, but designed for amateur construction, very many plans were sold.
Wing span: 9.88 m
Length: 4.96 m
Wing area: 16.65 sq.m
Aspect ratio: 5.88
Airfoil: Irv Culver
Empty Weight: 45 kg / 100 lb
Gross Weight: 136 kg / 300 lb
Wing Load: 7.9 kg/sq.m
Vzmin: 1.1 m/sec
Glide Ratio: 12 @ 62 kph
Takeoff distance: 31 m
L/DMax: 12 32 kph
MinSink: 0.96 m/s 30 kph (18-20 mph)
Cruise: 16-25 mph
Stall: 15 mph