Potez 26

The Potez 26 was a lighter, smaller span, single-seat fighter version of the two-seat biplane Potez 25 reconnaissance aircraft. Both types were sesquiplanes with markedly smaller lower wings.[1] Both upper and lower wings were rectangular in plan, with long-span ailerons only on the upper plane. They were single bay biplanes, their wing interconnected by N-form interplane struts assisted by wire bracing. These interplane struts leaned outwards and narrowed to meet the closer spars of the smaller-chord lower wing. Centrally, the upper wing was held over the upper fuselage by two pairs of struts, a parallel pair forward and an inverted V at the rear forming a cabane. There was a semicircular cut-out in the upper trailing edge to improve the pilot's forward view.[2]

The Potez 26 was powered by either a 340 kW (450 hp) Hispano-Suiza 12J V-12, or the 340 kW (450 hp) Lorraine 12Ed W-12, both cooled by a radiator under the rear of the engine cowling. The engine mounting enabled a rapid exchange of engines; the Lorraine W engine installation reduced the overall aircraft length by 350 mm (13.8 in). The mounting formed part of the forward fuselage structure, which had a plywood skinned central section containing the open cockpit,[1] raised above the structural fuselage, with decking falling away ahead and behind[2] and a wooden framed, fabric covered rear.[1] At the rear, the tailplane was mounted on the upper fuselage structure and externally braced to it from below with pairs of inverted V struts. Its fin was small and round edged, carrying a broad, deep rudder which reached down to the keel.[2]

The Potez 26 had a fixed tail wheel undercarriage with mainwheels on a split axle supported centrally by a V-strut, hinged on another pair of struts to the lower fuselage and with vertical, airfoil section shock absorbers.[1] There was a sprung tailskid.[2]

The Potez 26 made its first flight in August 1924[3] and was on display at the 1924 Paris Salon.[1] Only one was built.[3]

Data from L'Aérophile Salon-1924[1][4]

General characteristics

• Crew: One
• Length: 7.65 m (25 ft 1 in)
• Wingspan: 12.0 m (39 ft 4 in)
• Height: 3.15 m (10 ft 4 in)
• Wing area: 32 m² (340 sq ft) (upper 26.5 m² (285 sq ft), lower 5.5 m² (59 sq ft))[2]
• Empty weight: 1,100 kg (2,425 lb)
• Gross weight: 1,550 kg (3,417 lb)
• Powerplant: 1 × Lorraine 12Ed W-12 water-cooled piston engine, 340 kW (450 hp)
• Propellers: 2-bladed

Performance

• Maximum speed: 250 km/h (160 mph, 130 kn) at 5,000 m (16,000 ft)
• Service ceiling: 8,500 m (27,900 ft)
• Time to altitude: 5,000 m (16,000 ft) in 20 minutes
• Landing speed: 90 km/h (56 mph)

Armament

• Two fixed, forward firing 7.7 mm (0.303 in) Vickers machine guns on top of engine cowling.