Neukom Elfe M / Elfe S-1 / Elfe S-2 / Elfe S-3
The Elfe series started from a 9 m sailplane designed by W.Pfenninger before World War II. Just after World War 2 Albert Neukom of Switzerland began the creation of a line of sailplanes bearing the name EIfe; the first of these, the EIfe 1, had a wing span of only 9m (29 ft 6.25 in), later increased to 11m (36 ft 1 in).
A new design was introduced in 1947 to become the Elfe 2, probably the first sailplane with a laminar flow airfoil. The EIfe 2, with a span of 50ft 6.25in, had camber-changing flaps.
Subsequently the series was further developed by Albert Neukom with the Elfe M with laminar flow wings, Elfe MN and AN66 before the Standard Elfe S-1 appeared in 1964 with a V-tail. The prototype high performance single-seater Standard EIfe S-1 first flew on 1 May 1964. This was followed by the S-2 with conventional tail with the tailplane at the base of the fin.
The S-3, the production model of the S-2, first flew in May 1966 with a tailplane fixed part of the way up the fin. It has trailing edge airbrakes and a rubber-sprung retractable main wheel. The EIfe S-3 has a high cantilever wing built in three parts, and of plywood-balsa sandwich construction; it is fitted with trailing edge air brakes. The fuselage and tail unit are of glassfibre and plywood sandwich construction, while the landing gear consists of a retractable rubber-sprung monowheel with brake. The pilot sits upright under a removable transparent canopy.
Flown by the Swiss plot Markus Ritzi, a Standard EIfe took 2nd place in its class at the 1965 World Gliding Championships held at South Cerney, and at the 1968 World Championships at Leszno in Poland a Standard EIfe S-3 flown by Andrew Smith of the USA came 1st out of 57 entries, with other Elfes placed 4th and 6th.
A total of 18 Standard Elfes were flying by April 1970, the year in which the developed S-4A EIfe 15 first flew.
Standard EIfe S-3
Wing span: 15 m / 49 ft 2.5 in
Wing area: 11.9 sq.m / 128.1 sq.ft
Length: 23 ft 1.5 in
Height: 4 ft 11 in
Empty Weight: 208 kg / 459 lb
Payload: 112 kg / 246 lb
Gross Weight: 320 kg / 705 lb
Wing Load: 26.89 kg/sq.m / 6.79 lb/sq.ft
Aspect ratio: 19
L/D Max: 37.5 @ 95 kph / 51 kt / 59 mph
Min Sink: 0.64 m/s / 2.1 fps / 1.24 kt at 47 mph
Max speed: 150 mph (in smooth air)
No. of Seats: 1
Structure: Balsa/ plywood sandwich wing; glass fibre/ plywood sandwich fuselage