The Scheibe SF-27 Zugvogel V (English: Migratory Bird) is a single-seat Standard Classsailplane, designed and built in Germany in the 1960s. A motorised version was also produced. Significant numbers remain active.
The SF-27 is a shoulder-wing, single-seat Standard Classsailplane, succeeding the Scheibe Zugvogel IIIB in production. It was designed to 1960s Standard Class competition rules requiring a span of no more than 15 m and a fixed undercarriage. Built of wood and steel, its structure was conservative; at a time when many manufacturers were using glassfibre structurally in wings and fuselages, the SF-27 only used it to cover the forward fuselage.[1]
The wing of the SF-27 is built around a single beechwoodboxspar, with plywood ribs and a leading edge torsion box. The wing covering is largely ply, entirely so over the outer section. The inner section is covered with ply from the leading-edge to behind the spar, the rest with a mixture of ply and fabric. Ailerons and Schempp-Hirth airbrakes are likewise ply covered. The cantilever horizontal tail is an all-moving ply and fabric-covered surface, set at the top of the fuselage; the fin is covered with ply and the rudder with fabric.[1]
The fuselage is a welded steel structure covered, from nose to wing trailing edge, with a glassfibre shell. The wing root fairing is also glassfibre. Further aft the fuselage is fabric covered over wooden stringers. The cockpit, within the glassfibre shell, has a single piece Plexiglascanopy, the pilot sitting in a semi-reclined position. The SF-27 has a fixed monowheel undercarriage, fitted with brakes, plus a small tailwheel.[1]
The SF-27 first flew on 12 May 1964. 30 had been built by February 1966,[1] the final total being about 120. Scheibe also produced a motorised version, the SF-27M, with a 26 hp (19 kW) 4-cylinder Hirth F-102 A2 two stroke engine on a retractable mast above the wing behind the cockpit. Its gross weight is increased to 386 kg (850 lb) and it is 115 millimetres (4.5 in) longer, with a best glide ratio 32:1.[2]
