page_title: Salmson-Béchereau SB-5
section_title: Design
hierarchical_section_title: Salmson-Béchereau SB-5 / Design
caption_attribution_description: English: Salmson-Béchereau C.2 photo from Les Ailes April 15, 1926
context_page_description: The Salmson-Béchereau SB-5 was a two-seat fighter aircraft built for a French government programme in 1925. Despite a powerful engine it did not perform well and only one was built.
context_section_description: The Salmson-Béchereau SB-5, sometimes known as the Béchereau C.2 (C.2 denoting a two-seat chasseure or fighter) was Salmon's response to the French 1925 two seat fighter programme. Its strut-braced, parasol wing design owed much to Béchereau's  1921 Letord-Béchereau 2 and 1924 Buscaylet-Béchereau 2 single seat fighters and, like them, it used a similar type of 370 kW (500 hp) Salmson 18Cm eighteen cylinder water-cooled radial engine.
  The wing of the SB-5 was in two parts, joined low over the fuselage by a pair of cabane struts.  Beyond the section, where a pronounced reduction (c.50%) in chord, particularly on the trailing edge, provided a better field of view for the pilot, the wings were straight edged and of constant chord out to almost square tips.  The wings were mounted with about 2° of sweep and 3° of anhedral.  Each half-wing was built around two spruce longerons with pine ribs and plywood covered at the leading edge with fabric elsewhere.
  It was noted at the time that the wings were very thin and so required elaborate struttage which also involved the fixed landing gear.  The central part of the latter was a wooden airfoil section, 3 m (9 ft 10 in) span plane which contributed an extra 13% lifting area. This had metal carriers at its tips, each supported by a pair of almost parallel struts to the lower fuselage. Split axles, mounted centrally on a transverse V-strut from the fuselage, were connected to the carriers via rubber shock absorbers and mounted the wheels. The main wing struts converged slightly from the carriers to the wing longerons at about 80% span. From near the midpoint of these struts a further pair of inverted Vs braced the inner wing to the upper fuselage.
  The forward part of the SB-5's fuselage was designed around the 390 kW (520 hp) Salmson 18Cmb water-cooled radial engine, which was set back from the propeller on a 1.00 m (3 ft 3 in) extension shaft.  The fuselage was built around four longerons but had a near-circular cross-section shaped by formers and covered with fabric.  The pilot's open cockpit was entirely under the central trailing edge opening and the rear cockpit was very close behind, still partly forward of the outer trailing edge. The intention, probably never realised, was that the SB-5 should have two fixed, forward firing 7.7 mm (0.303 in) machine guns controlled by the pilot and another pair on a flexible mount for the gunner. The fuselage tapered to the rear with a ridge fairing which began behind the gunner's cockpit, ran along the spine and blended into a slightly rounded, low and broad fin, integral with the fuselage, which carried a pentagonal rudder.  The SB-5's tailplane, at the top of the fuselage, was generous and more rounded in plan than the fin and braced on each side by a strut from below. Its elevator trailing edges were level with the rudder hinge.
caption: Salmson-Béchereau C.2 photo from Les Ailes April 15, 1926
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