M.Simons The World's Vintage Sailplanes 1908-45
THE SPYR SERIES
The Spyr sailplanes designed in Lucerne by August Hug, began with the 15 metre span Spyr which made its first flight in April 1931. The Spyr was a light, handy sailplane. It had a straight-tapered cantilever wing of single-spar, ДальшеMore>>>
ply-covered 'D'-nose type, with no dihedral, mounted, with an ingenious quick-rigging system, on a narrow pylon behind the cockpit, the fuselage being of hexagonal cross-section. The cockpit was open and the pilot’s head tucked under the wing leading edge. Hug employed a strong central keel like that of a primary glider, the cross-frames of the fore end of the fuselage being erected on this with the controls and the seat, before the plywood covering was added. The tailplane was all-moving, and was pivoted at the extreme end of the fuselage. The rudder was tall and narrow. Pictures taken at a later time show the Spyr 1 with rudders of different shapes. The final arrangement probably resembled the tall, high aspect ratio rudder that appeared again on the prototype Spyr 3.
With the Spyr prototype, Willy Farner made the first Swiss cross-country flights by sailplane in 1932, from the Jungfraujoch. Two Spyr 1s were built.
The Spyr 2 was disappointing. A test flight report dated 1934 described it as extremely sensitive and tricky to fly. with tail flutter at speeds around 60 km/hr and 45 km/hr, so that it could be flown comfortably only between 45 and 60. The Spyr 3 followed quickly. The wing was again very strongly tapered, cantilever, with the Goettingen 535 profile at the root and 533 at the tip with generous washout to prevent tip stalling. As before there was a tall, narrow wing mount pylon but the cockpit was enclosed by a simple, wrap-around transparent plastic sheet. The fuselage was still the same hexagonal-sectioned plywood covered box, and so was easy to build. A landing skid was fitted and the tailplane was of the aerodynamically balanced type, as was the rudder. The first flights were made in 1934. The sailplane was found to be stable but still very sensitive and difficult for inexperienced pilots, especially in cloud flying. Later in the same year. Georg Mueller built a modified version, the Spyr 3a, which had a gull wing and a semi-streamlined fuselage.
In 1936 Fritz Schreiber broke the Swiss National duration record with a 25 hour 46 minutes flight, and soon afterward both the distance and altitude records were taken by Spyr 3 pilots. In 1937 two of the four Swiss sailplanes sent to the International Competition at the Wasserkuppe, were Spyr 3s. Although slow compared with the best German and Polish sailplanes present, the Spyr 3 did very well. Sandmeier ended the contest in fourth place. In the following year a Spyr 3 made the first out-and-retum goal flight ever done in Switzerland.
Six Spyr 3 sailplanes were registered still in 1940. One is preserved today in the Swiss Transport Museum, Verkershaus, in Lucerne. This aircraft has a fin and rudder quite different from the prototype and more like the Spyr 4 of later times. Photographs show that several shapes of rudder were fitted at various times to Spyr 3 sailplanes. The museum example also has a modified cockpit canopy.
The Spyr 4 was a larger, heavier and faster sailplane intended for cross-country flying. With its 'gull' dihedral and swept-forward configuration, the wing structure was complicated. The fuselage cross-section was of the ‘bulged hexagonal’ form with closed canopy. The tail unit was designed for greater stability and less sensitivity than the Spyr 3. Tested first in 1941, the Spyr 4 had little chance to prove itself as a cross-country type. It was regarded as a great improvement on the Spyr 3 and with its comfortable cockpit and graceful appearance, was very popular with pilots. One of the type survived to fly at vintage meetings in 1974 and later years.
August Hug, in 1975, was awarded the Lilienthal Medal of the CIVV, the highest award the organisation can bestow on a designer.
Technical data:
Spyr 3: Span. 16.00 m. Wing area, 13.55 sq m. Aspect ratio, 18.89. Empty weight, 108 kg. Flying weight, 183 kg. Wing loading, 13.5 kg/sq m. Best glide claimed. 1 : 27. Minimum sinking speed. 0.55 m/sec.
Spyr 4: Span. 16.40 m. Wing area, 13.6 sq m. Aspect ratio, 19.78. Empty weight. 180 kg. Flying weight, 260 kg. Wing loading. 19.1 kg/sq m. Best glide claimed. 1 : 30.
A Spyr 3, carrying an advertisement for Longines, on winch launch.
One of the Spyr 3s flown by Bauer at the International Competitions in 1937. The contest number 9 on a red and white striped diamond, and the words Zwieback Singer, appeared on the fuselage. Other sailplanes visible are, on the left, the Czechoslovakian Tulak 37 (registered OK-CECHY) and on the right, one of the Polish PWS 101s (SP-1005) with a Condor beyond it.
View of the Mu 10 in the hangar at Salzburg in 1937. The modified rudder, ailerons and canopy are well shown. The exact significance of the comical bird on the nose is not clear. Other sailplanes visible include the Rheinland (D-12-99), a Condor 2A, the tail of a Habicht, and a Swiss Spyr 3 in the background. The other types cannot be identified.
