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Siren E 75 Silene France
Designed by Siren SA, this side-by-side two-seater training sailplane of 18m span was originally known as the CERVA CE 75 Silene, the letters CERVA standing for Consortium Europeen de Realisation et de Ventes d'Avions, ДальшеMore>>>
which was owned jointly by Siren SA and Wassmer-Aviation SA. Design of the Silene, which was the first French two-seater of glassfibre construction, began on 1 January 1972 and construction of the prototype by CERVA began on 1 February 1973; this first flew at Argenton on 2 July 1974. The Silene was intended to be suitable for all stages of training from ab initio to cross-country flights, and Siren SA was responsible for marketing it; by early 1978 40 Silenes had been ordered and six of them flown. But following the bankruptcy of Wassmer-Aviation, which built the wings and was the co-partner in CERVA, the President of Siren formed Societe Issorie-Aviation late in 1977, taking its title from Wassmer's Aerodrome d'Issoire works, to continue production of the Silene, now known as the Siren E 75, and the D 77 Iris. The first six Silenes had a retractable rubber-sprung monowheel but a non-retractable monowheel can if the customer desires also be fitted as optional, and a Siren hydraulic brake is optional; there is also a tailskid. French certification of the type was granted on 3 February 1978 and planned output for 1978 was two per month, with Siren SA building the fuselages. Construction is entirely of glassfibre/polyester/PMC sandwich, and the cantilever mid-set wings, of Bertin E55-166 aerofoil section, have 2° forward sweep at the quarter-chord line. The two-section ailerons have spring tabs and there are Schempp-Hirth air brakes above and below the wings. The fuselage is a semi-monocoque, and the two pilots' semi-reclining seats are slightly staggered, the starboard seat being a little to the rear, so as to keep fuselage width to a minimum; oxygen systems can be installed if desired. The rear section of the two-piece canopy is hinged to open to starboard, and is jettisonable. There is a low-set fixed-incidence tailplane with a spring tab in each elevator.
The E 78 Silene is a new variant featuring improved and roomier accommodation for the pilots, an enlarged cockpit canopy, lowered seats and a slight increase in available cockpit width; the E 78B is the same as the E 78 but with a fixed monowheel. This was followed by the 1 79 variant
which has flaps and provision for water ballast, and was under development in 1979. The modified wings incorporate carbon-fibre components, and the flaps, air brakes and monowheel are hydraulically actuated.
Data: E 75 Silene
Span: 59 ft 0 1/2in
Length: 26 ft 1 in
Height: 4 ft 11 in
Wing area: 193.8 sqft
Aspect ratio: 18.0
Empty weight: 805 lb
Max weight: 1,246 lb
Max speed: 124 mph (in smooth air)
Max aero-tow speed: 105 mph
Min sinking speed: 2.20 ft/sec at 56 mph
Best glide ratio: 38:1 at 59 mph