The Schwan

A Swedish experimental ornithopter glider by Walther Filter

I would never expect to see a model of this unusual glider, but always hope to be proved wrong. I have collated the information on this glider basically for its' interest value.

The Schwan (Swan) was perceived in 1955 and appeared in two versions as an experimental development. The second of these is still on display at the Aviation Museum Hannover-Laatzen.

The Schwan 1

The following extract is from the Flight Magazine of 1958 following a visit to the Hannover Airshow

Guaranteed to make any visitor stop, stare and blink on entering the display hall was the prominently mounted Swan I ornithopter —or Schwingenflugzeug, to quote the designer, Walter Filter. This single-seater prototype has a tow-hook under the nose and will be aero-towed as a sailplane, the occupant using leg-muscle power after release to operate a mechanism which flaps the outer wing sections and, it is hoped, delays the effect of gravity.

This aircraft has not yet flown, and an increase in tailplane area may well be effected before the first flight. The angle of incidence of the five feather-like aerofoils forming each of the two outer wing panels varies throughout the flapping cycle.

The 13-metre Swan 1 has a flying weight of 730 lb and is to be followed, once the principle of the design has been proved in flight, by a two-seater, 15-metre Mk 2 weighing 1,210 lb and a six-seater, 20-metre version of 2,980 lb. The Mk 2 would be powered by a turbine engine for take-off, and the Mk 3 would have a fuselage-mounted power unit to actuate the flapping wings.

A flapping wing with staggered wing tips of the manned “Schwan 1”, developed by Walther Filter (1956, at the Hannover fair 1958). The angle of incidence deflection of the “feathers” designed as several wings was controllable.

From projects on to actual aircraft, me most interesting of which at Hanover were perhaps the brace of RW.3 Multoplanes shown by the Rhein-Flugzeugbau company. Aptly described as a multipurpose aircraft, the RW.3 is a tandem two-seater powered by a 65 h.p. Porsche engine driving a pusher propeller mounted in a vertical slot in the fin. As mentioned by Walter Neumark in his article on flying the prototype RW.3 in Flight of December 27, 1957, eight-foot wing extensions can be fitted to give a useful gliding performance with the engine switched off.

The Schwan 2

Again the special design of the outer wings of the bird's flight were intended to be imitated. After a successful launch by winch or tow the outer wings were to be operated by sheer muscle power using foot pedals to produce an up and down motion. The basic concept was to try and give the glider more lift when there was a lack of thermal activity, however the Federal German aviation administration did not allow any flying with this unusual gilder.

Translation of the above Sign:

Oscillating Ornithopter, SWAN 1

Length 5.2 m
Span 13 m
Flight Weight 286 kg approx.
Wing Loading 18 kg/ sq. m

The construction of the sailplane requires the start to be made with aerotow or winch and for this the wing "feathers" are loced in the middle position. After release the pilot uses both his feet to to oscillate the "fetahers" up and down simlatneously by + / - 15º