M.Simons The World's Vintage Sailplanes 1908-45
THE FALKE
The Pruefling was not popular as a secondary trainer, for its performance was only a little better than the Zoegling and it was quite tricky to fly. Lippisch realised that a ‘secondary’ which would fly in rough air over the slopes ДальшеMore>>>
for early soaring experience, needed greater stability and tolerance. He designed the Falke (Falcon), to replace the Pruefling.
Drawing on his experiences with the tailless Storch, it occurred to Lippisch that the best way to ensure a stable glider would be to design the wing as if it were to fly tailless, and then add a tailplane as well. The Falke wing was almost the same as the Storch 4, with sweep and a generous negative twist or ‘washout’ toward the tips, and a reflex profile on the lobate ailerons to ensure that they would never become ineffective. The wingtip end fins used on the Storch were not copied on the Falke, which had an orthodox fin and rudder. The wing was difficult to build in wood. The sweep, washout and reflex aileron profiles all required high standards of craftsmanship and accurate jigging in the workshop. For some reason Lippisch decided to complicate things even more by incorporating a barely detectable kink or ‘gull’ dihedral form in the wing.
Balance requirements dictated that the pilot must sit under the wing. Behind the cockpit a strong pylon took the rear spar fittings whilst on either side at the front of the cockpit, braced struts ran up to the front spars. Large ‘V’ struts were attached to the main frame behind the seat. A bracing wire ran from the front strut fitting on the wing, to the extreme nose. The aileron control cables came up on each side and ran into the wing. The pilot sat in the midst of a sort of cage, with no upward view, struts and wires all round. By comparison the fuselage and tail were simple.
Lippisch achieved all his main objectives for the Falke was strong, light, and stable. It was adopted widely in Germany and remained, until the advent of the Grunau Baby in 1932, the standard secondary training type. Drawings were produced and sold by the RRG. The type was built in some quantity by professional glider manufacturers, especially Schleicher at Poppenhausen, Edmund Schneider at Grunau in Silesia, and by Segelflugzeugbau Kassel.
In 1931 the Falke R Va was produced with a span of 13.2 m. The ‘V’ struts were replaced by diverging struts from the wing spar fittings down to the fuselage. One attached to the bottom of the fuselage frame ahead of the cockpit, and the rear strut ran to the frame one bay aft of the pilot’s seat. The reason was almost certainly to relieve the stresses on the single frame which, in the older Falke, had carried all the loads from the lower end of the ‘V’ struts, the pilot’s seat, and the landing shocks through the skid support at this point. On these later Falkes, the cabane was also changed to have four vertical struts instead of two at the front and a rear pylon.
A larger version, the Super Falke, with span of 16.88 metres, was flown but in 1933 it was destroyed in a fatal aerotowing accident when the glider got out of position above the tug, was overloaded, and the wing collapsed.
One Falke 1, rescued from storage in the roof of a ski lift in the Alps by Klaus Heyn, and perfectly restored by him, still exists in museum condition in Germany.
The performance figures and weights given below for the Falke R Va, were measured by the DFS in flight and reported by W. Spilger in 1938.
Technical data:
RRG Falke: Span, 12.60 m. Wing area. 18.12 sq m. Aspect ratio. 8.76. Sweepback, 12.5 deg. Empty weight, 165 kg. Aerofoil, Goettingen 535 modified at root, changing to reflex profile at mid-aileron position, thence to thin symmetrical section at the tip, with strong washout progressively from the strut position to the tip.
RRG Falke R Va: Span. 13.20 m. Wing area. 17.84 sq m. Aspect ratio, 9.76. Empty weight, 165 kg. Flying weight, 270 kg. Wing loading, 15.1 kg/sq m. Best glide ratio, 1 : 19.0 at 64.5 km/h. Minimum sinking speed 0.93 m/sec. Rate of sink at 100 km/h. 2.58 m/sec.
A line-up of rarities at Brooklands. From the foreground: Slingsby Falcon I replica; Slingsby Gull III; Schleicher Rheinland; Manuel Willow Wren BGA 162; Abbott-Baynes Scud II; Hols der Teufel replica; Bleriot XI G-LOTI.
Herr Krause, whose attempt to advertise Lyons Tea by gliding the Channel in his "Falke," was forstalled by Herr Kronfeld.
Fred Slingsby in a Slingsby Falcon 1 at the Furness Meeting, September 1932.
The Falke was built in quantity by professional sailplane manufacturers. This example, the Grunau Falke, as its name indicates, came from Edmund Schneider's factory in the Riesengeberge. The ESG emblem appeared on the rudder. The men at the tail held the glider back as the launching crew stretched the rubber bungee.
The British Falcon or Slingsby Type 1 being launched at the London Gliding Club’s site at Dunstable, Bedfordshire, circa 1933.
Fred Slingsby flying a Falke over the Yorkshire Moors. He put this German glider into production as the Slingsby Type 1 Falcon 1.
John Sproule’s Lippisch Falke at Lasham.
A Falke built by a gliding club at Muenster. The complex structure was very difficult for amateur workmen.
One of the enlarged and improved Falkes, the Falke R Va, with diverging main wing struts instead of the 'V' strutting of the earlier version. The divergent struts distributed the loads more safely than the old 'V' struts. The skid was sprung by two hard rubber rings compressed by the weight when on the ground. Hill soaring in snowy conditions, in open cockpits, way by no means unusual.
Wikipedia