Potez 54 / 540 / 541 / 542
This two-engine aircraft was built as a private venture by the French Potez company to fulfill a 1932 specification for a new reconnaissance bomber. Designed by Louis Coroller, designated the Potez 54, it was intended as a four-seat aircraft capable of performing duties such as bomber, transport and long-range reconnaissance. The Potez 54 was a high-wing monoplane, of mixed wood and metal covering over a steel tube frame. The prototype had twin fins and rudders, and was powered by two 515 kW (690 hp) Hispano-Suiza 12Xbrs V-12 engines in streamlined nacelles, which were connected to the fuselage by stub wings. The main landing gear units retracted into the nacelles, and auxiliary bomb racks were mounted beneath the stub wings. There were manually-operated turrets at the nose and dorsal positions, as well as a semi-retractable dustbin-style ventral turret. The main landing gear units retracted into the nacelles, and bomb racks were mounted beneath the stub wings.
The Potez 54 M.4 category prototype flew for the first time on 14 November 1933 and during development, the original tailplane was replaced by a single fin and rudder, and in this form, the type was re-designated the Potez 540 and delivered to the Armee de I'Air on 25 November 1934.
Parallel with the Potez 540 were developed the Potez 541 prototype, powered by Gnome-Rhone 14Kdrs radials, and the Potez 542 with 537kW Lorraine Petrel engines.
All versions had defensive armament of manually-operated nose and dorsal turrets and a semi-retractable ventral 'dustbin' position; radio, oxygen, night and blind flying equipment were standard, and reconnaissance cameras could be carried.
A total of 192 Potez 540s were built.
In early 1938, the Ilmavoimat / Maavoimat test team evaluated the Potez 540. Given the role that the aircraft was expected to fill, the evaluation was cursory and simply confirmed that the aircraft was completely unsuited to the intended role and should not be considered further. In point of fact, the evaluation team were highly annoyed that the French would even put the aircraft forward for consideration given the obvious unsuitability when evaluated against the requirements the Ilmavoimat had provided.
Their first combat was in the Spanish Civil War, where they were employed by the Spanish Republicans. In the late 1930s, these aircraft were becoming obsolete so they were withdrawn from reconnaissance and bombing duties and were relegated to French transport units. They were also employed as paratrooper training and transport aircraft. By September 1939 and the beginning of World War II, they had been largely transferred to the French colonies in North Africa, where they continued to function in transport and paratrooper service. Their role in even these secondary assignments was problematic given their poor defensive armament and vulnerability to modern enemy fighters. Following the French capitulation to Germany in June 1940, those Potez 540s still flying served the Vichy French Air Force mainly in the French overseas colonies. Most of these machines were retired or destroyed by late 1943
Engine: 2 x Hispano-Suiza 12Xirs / Xjrs, 515kW / 690 hp
Max take-off weight: 5950 kg / 13118 lb
Loaded weight: 3785 kg / 8345 lb
Wingspan: 22.1 m / 73 ft 6 in
Length: 16.2 m / 53 ft 2 in
Height: 3.88 m / 13 ft 9 in
Wing area: 76.0 sq.m / 818.06 sq ft
Max. speed: 310 km/h / 193 mph
Ceiling: 5182 m / 17000 ft
Range: 1250 km / 777 miles
Armament: 3 x 7.5mm MAC 1934 machine-guns
Bomb load: 4 x 225kg or 10 x 55kg