From 1956 until at least 1964
Wassmer built and developed the successful
Javelot series of single seat gliders. These had wooden wings with
NACA laminar flow profiles and steel framed
fuselages, covered entirely with
fabric on early models but later with a mixture of fabric and
glass fiber. The Squale was attempt to break into the high performance market. Like the Javelots, it had a wooden wing but one with a Wortmann profile; its fuselage was a more aerodynamically refined and wholly
GRP structure. The straight edged
high wing of the Squale has a slightly tapered centre section of about 60% of the span and more strongly tapered outer panels. There is constant
dihedral across the whole span. The
ailerons are on the outer panels, with
airbrakes on the
trailing edges of the outer centre section. The wing is built around a single wooden spar, with wooden ribs and 2.3 mm (0.1 in)
plywood skin. The straight tapered,
all moving tail of the Squale is also wooden, with a ply covered
leading edge and fabric covering aft. It is
shoulder mounted on the fuselage. The early Squales lacked elevator feel, so
anti-balance tabs were added on the WA 26M version. The straight edged, swept
fin and
rudder, the latter
horn balanced, are GRP structures, integral with the fuselage. This has an oval section which gradually increases in diameter forwards to the wings. There is a retractable
monowheel undercarriage, fitted with an hydraulic brake and assisted by a small, fixed tailskid. The pilot's semi-reclining position is under a long, single piece
canopy which hinges to port. The Squale sold quite well; after its first flight on 21 July 1967, production began the following year and by January 1970, 85 had been ordered. Recognition that wooden-winged gliders were becoming outdated resulted in a redesigned wing, aerodynamically the same as the WA 26 Squale but built of GRP and fitted with Schempp-Hirth rather than trailing edge airbrakes. This led to the
WA 28 Espadon, the new wing mounted on a Squale fuselage with a GRP all moving tail in place of the Squale's wooden one. The Espadon is 20–25 kg (44-55 lb) heavier than the Squale; its best glide ratio is 1:36 at 88 km/h (55 mph). It first flew in May 1974 and went into production that November; by the Spring of 1975, 20 were on order. It soon became apparent that competitors like the
Schleicher ASW 15 had significantly better performance and production did not continue for long. ==Operational history==