M.Simons The World's Vintage Sailplanes 1908-45

THE MOSWEY SERIES

  Georg Mueller and his brother built a primary glider in 1930 and made a reputation afterward by building the Spyr designs of August Hug. Their workshop was located in Wald-Zurich. In 1935 Georg brought out his own small, high-performance sailplane, the Moswey 2. It was a pretty design with many clever features and meticulous workmanship. The cantilever wing was straight-tapered in plan but had the ‘gull’ form of dihedral. The structure was normal with its mainspar and plywood-covered torsion-resistant leading edge, and fabric covering behind the spar. Like most Swiss gliders, the fabric was sewn to the ribs although in other countries this was not thought necessary.
  Each fuselage cross-frame was basically hexagonal in outline but the segments of the hexagon were curved outward. Construction was easier than for the fully streamlined form with numerous laminated wooden hoops, but the aerodynamic form was almost as good. Aft of the wing the hexagonal shape gradually transformed to a near-diamond at the tail. The cockpit was quite large, with some extra shoulder room provided by the opening of the wing roots. The inner bays of the wing leading edge were used for storage space. The canopy was fully enclosed. The rudder pedals were adjustable in flight by means of a screwed rod with a crank handle. The tail unit was of the fixed fin and tailplane type with hinged rudder and elevator. The ailerons had an extreme differential gearing of 10:1, the downward movement being only three degrees, the upward, 30. Spoilers were fitted on the upper surface of the wing.
  The Moswey was aerobatic, with a load factor of 12, and its small size and quick response to controls made it very popular for mountain soaring and air displays.
  The Moswey 2A was developed in 1939. It had an increased wing span of 15.5 metres with a higher aspect ratio and better performance, though at some cost in handling qualities.
  In 1942 the Moswey 3 flew and was put into series production. It was very similar in appearance to the Moswey 2, but incorporated many structural refinements. It had a slightly different span, and airbrakes. The ailerons were slotted to improve their effectiveness and the tailplane aerofoil was redesigned. All the cockpit controls were mounted on a central beam running longitudinally down the centre, under the pilot's seat and into the nose. The entire unit with rudder pedals, control column, spoiler-operating lever, tow release, undercarriage (a drop-off dolly) release, instrument panel and oxygen gear, could be assembled in the factory before being mounted in the fuselage. The fuselage shell and main cross-frames were assembled on a jig consisting of a tube of large diameter running down the long axis. Control rods, rather than cables, were used throughout.
  Rigging was so quick and easy that some regarded it as superior to any other system known. A hook-shaped extension of the main metal carry-through member in the fuselage, allowed each wing to be presented, slipped onto its hook, and automatically it was aligned ready for the main tapered pins to be inserted and tightened.
  The wing root junction was more carefully faired than on the Moswey 2, and a two-piece plastic moulding, cemented down the central spine where the two half-shells joined, formed the canopy.
  The Moswey 3 quickly became popular and 14 were built. In the years immediately after World War 2, most of the Swiss records were broken by Moswey pilots. At the first postwar International Championships, at Samedan, a Moswey 3 flown by Sigbert Maurer set the first world record for speed around a 100 km triangle, and Alwin Kuhn placed third over all in the Championships. Two years afterward Moswey 3s were still contending in the World Championships and Kuhn achieved eighth place in a sailplane whose basic design went back to 1935.

  Technical data:
  Moswey 3: Span. 14.00 m. Wing area. 13.1 sq m. Aspect ratio, 15.0. Empty weight, 130 kg. Flying Weight, 233 kg. Wing loading, 17.8 kg sqm. Aerofoil, Goettingen 535. Best glide, 1 : 25. Maximum permitted speed, 210 km/h.