PZL Bielsko SZD-19 Zefir 1 / Zefir 2
The Zefirs resulted from work done by a team under Dipl-lng B.Szuba and the SZD-19X Zefir 1 prototype, designed by B. Szuba, made its first flight on 4 January 1959 as an Open Class single-seater and this was followed by the SZD-19-2 Zefir 2, which first flew in March 1960. The first two examples of this version, flown by the Polish pilots Makula and Popiel, took 2nd and 3rd places in the Open Class in that year's World Championships in Germany. The Zefir aroused great interest here because of its advanced design features, in particular the reclining pilot's position that made possible such a well streamlined fuselage of low cross sectional area, the tail braking parachture, the towing hook unit combined in the retractable monowheel, and the swept back fin and rudder with the one-piece tailplane and elevator slotting into the tail cone below the rudder. The Zefir 2 went into limited production during 1963-64 and three improved Zefir 2As took part in the 1963 World Championships in Argentina; this time their pilots Makula and Popiel came 1st and 2nd in the Open Class and the Argentine pilot Rudolfo Hossinger, who had won the 1960 World contest in a Skylark 3, was placed 5th in a Zefir 2A. The cantilever shoulder wings were of 17m (55ft 9.5 in) span and 20.7 aspect ratio, with an NACA 65-series laminar flow section; each wing has a central plywood torsion box with a plywood/plastic core sandwich skin, a D-section leading edge and a plywood-covered trailing edge. The wooden ailerons are fabric-covered and the VZLU mechanically-operated slotted flaps are in six sections covering 35% of the chord; there are no dive brakes. The wooden fuselage has the monocoque nose section covered with glassfibre, the centre section and tail cone being ply-covered semi-monocoque structures, the drag parachute being housed in the tail cone. The tail surfaces have laminar flow sections, the fin and tailplane being covered with a sandwich skin and the rudder and elevators fabric covered, with a trim tab in the elevator. The long flush-fitting cockpit canopy slides forwards about Sin and then is opened by hinging upwards from the tip of the nose cone; radio, oxygen and blind flying instruments for the pilot are standard, and a termal detector can be fitted as an optional 'extra'.
The SZD-29 Zefir 3 was a much improved version of the SZD-19-2 Mk 2.