M.Simons The World's Vintage Sailplanes 1908-45
THE HJORDIS
In 1934, Mungo Buxton announced he was designing a new high performance sailplane to be called Hjordis after the heroine of a Norse saga he was reading at the time. The new type appeared at the British Nationals in August 1935. ДальшеMore>>>
Buxton chose a compromise span of 15.54 metres (51 ft) and a high aspect ratio of 21. The wing was given the highly cambered, thick Goettingen 652 profile designed to give best performance at low speeds. At the tip the profile was reduced to RAF 32. A very simple, tapered planform was used, with no dihedral, and even a suggestion of anhedral. Viewed from in front, the undersurface of the wing was flat, so the upper surface was inclined slightly downward to the tips. The normal plywood skin of the leading edge was carried back to the rear spar to increase torsional stiffness. It also had the merit of preserving an accurate profile.
The fuselage gave Hjordis a highly distinctive appearance. A slender, spindle-shaped tube of plywood, perfectly circular in cross-section, was suspended below the wing by a tall, narrow neck. The cockpit was cramped, there being only just enough room for the pilot’s shoulders, and it was neatly enclosed by a curved windscreen. A control wheel instead of a stick was used, to give the pilot a little more leg room. The tail unit followed conventional practice; all-moving elevators and rudder, mounted on the fuselage without any form of trimmer. There were neither flaps nor airbrakes, though Buxton had intended to make the rudder open like a clam shell if the pilot pushed on both rudder pedals simultaneously. This would have had some braking effect but it was not incorporated in the sailplane as built.
Early tests revealed serious lateral control problems. The wingtips twisted considerably when aileron was applied, the controls reversing at even moderate airspeeds. Also, when one wing was resting on the ground, it flexed enough for the skin to be punctured by stones. Both problems were overcome by re-skinning the outer wing with thicker plywood. Lateral control, in spite of this, was never very good.
When Hjordis emerged from Slingsby's workshops, it was taken over by Philip Wills. With the new sailplane Wills proceeded to win the prizes for altitude (1645 metres) and out-and-return distance flights at the Nationals. Fitting the Wills frame into the tiny cockpit was not easy. Wills complained of poor ventilation and cut large holes in the sides of the canopy to let his shoulders poke through and to let more air in. He broke the British distance record in July 1936, with a flight from Dunstable to the coast near Pakefield. In 1937, after a frightening experience test-flying the King Kite, Wills chose to take the Hjordis to the international competitions at the Wasserkuppe. He finished about half way down the final score sheet. He won the British Nationals that year.
The Hjordis was out of date by this time. The ‘Norse heroine’ was advertised for sale and early in 1938 was bought by an enthusiast in South Africa. No more was heard of it although the remains were reported to be still in existence in the years immediately following World War 2.
Technical data:
Hjordis: Span. 15.54 m. Wing area. 11.52 sqm. Aspect ratio. 21. Flying weight. 217.72 kg. Wing loading, 18.94 kg/sqm. Aerofoils. Goettingen 652 at the root, tapering to RAF 32 at the tip, 8 degrees washout. Best glide. 1 : 24.
Wills supervises the manhandling of the Hjordis at the Internationals. He had great difficulty in getting his tall frame into the cramped cockpit, and cut large holes in the canopy for his shoulders.
Mr. Philip Wills squeezing himself into the high-efficiency Hjordis sailplane (designer, Flt. Lt. G. M. Buxton). The coupe top is quickly detachable should an emergency exit by parachute be necessary.
Mr.P.A. Wills in the Hjordis, with his brother Richard who acted as interpreter, in attendance.
Launching Hjordis I: Although the span is 50 ft., the chord is very narrow, and the wing loading is unusually high for sailplanes. On this machine Mr. Wills broke the British distance record by flying from Dunstable to Lowestoft, 105 miles.
The Hjordis on a winch launch at Sutton Bank in 1935. At a time when few British pilots had seen any high performance sailplanes, it was regarded as very superior. if tricky to fly. The winch cable apparently had a rubber shock absorber inserted to make the launch smoother.
Philip Wills takes off at the Wasserkuppe in 1937. The Hjordis evidently had priority in the choice of registration letters.
Hjordis I over Sutton Bank. The first really high-performance sailplane designed and built in England (by Slingsby Sailplanes of Kirby Moorside). Stability has been to some extent sacrificed to performance. Controls are very effective, but have no "feel," and Hjordis gathers speed very rapidly indeed if the nose is allowed to fall by 2 or 3 degrees.
INTERNATIONAL: A scene at the Wasserkuppe on the first day of the International Gliding Competition. In the foreground can he seen Mrs. Ronald Price at the wing tip of her King Kite, while behind is the Hjordis, which is being handled by Messrs. P. A. Wills and J. C. Neilan.
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