Slingsby Hjordis
| Slingsby Hjordis | |
|---|---|
| Type: | Performance glider |
| Design country: | |
| Manufacturer: |
Slingsby Sailplanes , Kirbymoorside |
| First flight: |
May 27, 1935 |
| Production time: |
1935 |
| Number of pieces: |
1 |
The Slingsby Hjordis was a performance glider made by the British manufacturer Slingsby Sailplanes in the mid-1930s. The plane is named after the female legendary figure Hjördis in Norse mythology, but did not have the usual Slingyby type number. Only one copy was made. Sometimes the aircraft is also called the Buxton Hjordis after its main designer .
history
Constructors
The Hjordis was mainly designed by Mungo Buxton , a squadron leader of the RAF. Together with the pilot Philip Wills, he commissioned Slingsby to build the machine in 1934. Although the drawings by Buxton showed the essential construction features important for the construction, a large part of the execution details were only developed in the Slingsby workshops during construction and were never put on paper. Buxton was a well-known British glider pilot and author of related articles in the BGA magazine Sailplane & Glider . Wills was the second pilot in the UK to earn the Silver C license.
1935
The Hjordis first appeared in public at the British Gliding Association (BGA) competitions in Sutton Bank in 1935 . Wills won the de Havilland Cup for the best climb performance and the Manio Cup for a predetermined "cross-country flight" over 23.6 miles (38 km).
1936
In July 1936, Mills set a British course record with a flight from Dunstable to Lowestoft over 104 miles (166 km), but the limitations of the narrow cockpit proved very burdensome for the pilot. As an ad hoc solution, crescent-shaped holes were cut in the fuselage directly below the cockpit cover. From then on, Wills' shoulders were in the wind on all further flights.
The main disadvantage, however, turned out to be the lack of any spoilers or air brakes, which led to some minor landing accidents. Originally, spreading flaps were provided on the oars, which both move together when the oars are operated to the left or right. The braking function was activated by the pilot pressing both pedals at the same time, moving the two rudder flaps in opposite directions and thus generating high air resistance.
Wills was also able to win the overland flight award in the 1936 BGA competitions. A British champion has not yet been determined.
1937
The first international championships in gliding were held in Germany in July 1937 on the Wasserkuppe , with five British glider pilots also taking part. Again, Wills flew the Hjordis instead of the newer, but less reliable Slingsby King kite . Wills ended up in midfield 14th of the competition. Shortly after the return of the British team, the British National Championships were held in Derbyshire in 1937 under new rules, with special emphasis on cross-country flights. Wills won with three flights of over 68 miles (109 km) each.
Whereabouts
In 1938 Wills sold the Hjordis to a syndicate in Johannesburg , where it received the official aircraft registration ZS-23. In the photos from this period, however, she still bears her G-GAAA marking and the participant number 15 that she received for the 1937 competitions. The plane was flown in South Africa for a few more years, but its final whereabouts are unknown.
construction
The Hjordis had a cantilevered wing with a high aspect ratio and a strongly arched profile that was thick at the root. For this purpose, the Göttingen 652 profile was chosen, which was also used by DFS Fafnir by Alexander Lippisch , the Kakadu and Austria von Kupper. The wing sat on a high pylon, which also formed the pilot's "headrest". Viewed from the front, the underside of the wing was aligned exactly horizontally, only the decreasing thickness towards the tips gave the impression of a slightly negative V-position . The decrease in the depth of the wing, which is trapezoidal in plan, towards the tips, was very pronounced with a depth ratio of 1: 4. The plywood planking over the entire depth up to the rear spar, which was designed as an auxiliary spar, was unusual. In contrast to the wings of that time, which were covered with fabric from the front spar, the profile shape of the Hjordis was better preserved even under high loads and the wing had an overall higher torsional rigidity. However, the associated increase in weight was disadvantageous. All rudder surfaces were covered with fabric.
The hull was designed in half-shell construction, with four main longerons and circular frames supporting the plywood planking that extended over the entire hull.
The dimensions of the Hjordis, in contrast to most contemporary German constructions, were relatively small in order to enable them to be handled and operated by clubs that have only a few members.
The cockpit of the Hjordis was also exceptionally small and narrow. B. to the fact that the operation of the ailerons could not be done by swiveling the control stick to the side, but only by a small wheel on the control column.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| length | 6.58 m |
| span | 15.55 m |
| Wing area | 10.53 m² |
| Wing extension | 21.1 |
| Wing loading | 20.7 kg / m² |
| Airfoil | Root: Göttingen Gö 652 Tip: RAF 32 |
| Empty mass | 144.0 kg |
| Max. Takeoff mass | 217.47 kg |
| Max. flown speed | 200 km / h |
See also
literature
- Martin Simons: Hjordis (Sling's Sailplanes Part 3). In: Airplane Monthly. October 1992, ISSN 0143-7240 , pp. 25-28.