Neukom S-4A EIfe 15 / S-4A EIfe 17
Neukom S-4A EIfe
A developed version of the Standard EIfe S-3, the S-4A EIfe 15 differs from it principally in having a new two-piece wing of the same 15m span, strengthened and fitted with Schempp-Hirth air brakes; the single spar is of aluminium alloy and the wing skin of plywood/foam sandwich. A roomier forward fuselage of improved aerodynamic shape is featured, with the slight step forward of the canopy on the Standard EIfe S-3 completely eliminated. The fuselage and tail unit are of glassfibre and plywood/foam sandwich construction, and the landing gear consists of a retractable rubber-sprung monowheel with brake. The prototype EIfe 15 made its first flight in 1970 and 10 had been built by early 1973; production continues, although at a rather slow rate.
Both the EIfe 15 and EIfe 17 were available in kit form for amateur construction, the latter being a 17m span Open Class version of the S-4A EIfe 15, with the same fuselage but with a wider span two-piece wing, with provision for a tank in each leading edge to house a total of 132lb of water ballast. The EIfe 17 also has a braking parachute fitted, and a total of 10 of this version had been built by the spring of 1973, with production continuing at a relatively slow rate.
The EIfe M17 is a single-seat motor glider version of the Open Class EIfe 17 and first flew in prototype form in mid-March 1978. It is powered by a 45hp Parodi HP 45 four-cylinder four-stroke engine driving a Hoffmann two-bladed propeller; this is pylon-mounted aft of the cockpit and retracts into the fuselage when not in use. Electric starting is provided and the fuel tank capacity is 10 Imp gallons (45 litres). Apart from the engine and its related modifications the EIfe M 17 is the same as the unpowered EIfe 17.
Span: 55 ft 9.25 in
Length: 23 ft 3.5 in
Height: 4 ft 11 in
Wing area: 142.1 sqft
Aspect ratio: 21.8
Empty weight: 562 lb
Max weight: 837 lb
Max speed: 130 mph
Max aero-tow speed: 87 mph
Min sinking speed: 1.84 ft/sec at 46.5 mph
Best glide ratio: 39:1 at 56 mph