Neukom AN-66 Super-Elfe / AN-660
Neukom AN-66C Super EIfe
The Neukom AIM-66 high performance single-seater first flew in prototype form in 1966, and was followed by two others, designated AN-66-2, which featured a modified fuselage. These versions have cantilever shoulder-mounted wings of 18m (59ft 0.5in) span and of Eppler 441 aerofoil section, which are of sandwich construction with a metal spar and have plain flaps. The forward fuselage is a glassfibre sandwich structure, while the rear portion is a wooden plywood and balsa sandwich semimonocoque, and a 'butterfly'-type V-tail is fitted. The landing gear is a rectractable monowheel and the pilot sits under a long flush-fitting transparent canopy.
The AN-66C Super Elfe is a development of the AN-66-2 with the same fuselage but with an entirely new variable-geometry wing with a special aerofoil flap that can be extended to increase the wing area by about 20%; a conventional tail unit with a low-set tailplane, similar to that of the Standard Elfe S-3, replaces the AIM-66-2's V-tail.
Flight tests of the prototype AN-66C began at Butzweilerhof in Germany on 11 September 1973. The new wing has a longer span of 23m (75 ft 5.5 in) and the aerofoil flaps are chain-operated by a crank in the cockpit and can either be fully extended or fully retracted, no intermediate position being possible; when fully extended or retracted the wing profile is changed so as to result in a continuous Eppler aerofoil section. A tank to contain 132 lb of water ballast is situated in the leading edge of each wing centre section, the latter being 21 ft 4 in in length and the two outer panels 27 ft 0.75 in each. The single-spar wings have riveted duralumin double-T spars, and plywood/balsa/plywood sandwich outer skins formed by vacuum pressing; Schempp-Hirth air brakes are fitted. Landing gear consists, as it did on the AN-66-2, of a retractable monowheel and tailskid. The wing area is increased from 172.2sq ft with the flaps in, to 206.7sq ft with flaps extended, when the aspect ratio is 27.6 compared to 33.1 with the flaps in.
The AN-660 prototype, produced in 1974, has a four-piece wing of 21m (68 ft 11 in) span.
Span:75 ft 5.5 in
Length: 26 ft 6.25 in
Height: 6 ft 0.75 in
Wing area: 172.2 sq ft (flaps in)
Aspect ratio: 33.1 (flaps in)
Empty weight: 926 lb
Max weight: 1,433 lb
Max speed: 168 mph (in smooth air)
Min sinking speed: 1.64 ft/sec at 46.5 mph (flaps out)
Best glide ratio: 48:1 at 56 mph (flaps in)