The Dewoitine D.500 was a monoplane fighter aircraft featuring an all-metal structure, an open cockpit, and a fixed undercarriage, designed and manufactured by the French company Dewoitine.
Designed to fulfil a specification released by the French Air Ministry in 1930, the D.500 was aimed at being a more proficient successor to the Nieuport 62.
It was ordered by the French Air Force in November 1933 and its initial model was introduced in 1935.
The design evolved into multiple variants, with the D.510 being the most notable, as it was re-engined with the more powerful Hispano-Suiza 12Ycrs engine.
This aircraft gained a considerable level of popularity during the Interwar period; in France, apart from the units of the French Air Force, a specialised variant known as the D.501 was also acquired by the French Naval Aviation for operations on aircraft carriers.
In addition to its domestic use, the D.500 experienced several export transactions and assessments by potential major clients, including the Empire of Japan, the Soviet Union, and the United Kingdom.
The D.500/D.501 engaged in combat with various operators.
During the Spanish Civil War, it was covertly provided to the Spanish Republican Air Force; it was also utilised by the Republic of China Air Force against the invading Japanese during the Second Sino-Japanese War.
In the late 1930s, this aircraft type was predominantly replaced by a new generation of French fighter planes, which typically incorporated further advancements such as enclosed cockpits and retractable landing gear, including the design’s direct successor, the Dewoitine D.520.
Although largely outdated, both D.500s and D.510s were utilised by the French Air Force during the early months of the Second World War, with the latter remaining operational until the conclusion of the Battle of France and the signing of the Armistice on 22 June 1940 between France and Nazi Germany.
The Dewoitine D.500 was a cantilever monoplane with a low-wing design made entirely of metal. It boasted a sharply contoured fuselage, featuring a streamlined nose section that accommodated the aircraft’s powerplant, which consisted of a single Hispano-Suiza 12Xbrs V-12 liquid-cooled piston engine capable of producing up to 515 kW (691 HP).
Beneath the fuselage, there was a relatively large radiator designed to minimise the frontal area while adequately fulfilling the cooling needs of the Hispano-Suiza engine.
The cockpit of the D.500 was positioned directly above the trailing edge of the wing.
The pilot was provided with a chair that could be adjusted vertically, allowing for elevation during flight to enhance visibility during landing.
Additionally, the cockpit was outfitted with oxygen equipment and a radio set for communication purposes.
The control stick was linked to the aircraft’s ailerons through a rod transmission connected to horns located on the upper surface of the wing.
Due to the aircraft’s high-speed capabilities, the control surfaces of the D.500 were relatively small.
The D.500 featured a monocoque fuselage with an ovoid cross-section, constructed from five primary and eight false bulkheads interconnected by four longerons and intermediate stringers; these elements reinforced the metal sheet covering, which was riveted to the structure.
The sternpost was an integral part of the fuselage, while the engine bearer, consisting of an oblique frame, was directly affixed to the crankcase’s attachment brackets.
The aircraft’s adjustable stabiliser was pivoted around its front spar, and rigid struts were linked to both sides of the lower fuselage to enhance transverse stiffness.
The fixed undercarriage was equipped with faired axle-less wheels, featuring pneumatic brakes, mounted on a pair of V struts that were secured to the lower fuselage longerons.
The vertical loads on the undercarriage are managed by an oleo-pneumatic strut that is bolted to the central wing’s single spar and is integrated with the fuselage.
The D.500 featured a low-mounted elliptical cantilever wing constructed entirely of metal, boasting an aspect ratio of 8.9.
It possessed a relatively narrow chord and was designed with a single spar, akin to the record-holding Dewoitine D.33.
The wing’s structural integrity was derived from its box spar, which consisted of two vertical sheets of metal that were connected to the flanges, which were subsequently riveted to the flat sheet rib arcs of the covering.
The thickness of the wing measured 0.3 m (11.81 in.) at the root, tapering smoothly towards its rounded tips.
Balanced ailerons spanned the entire length of the wing, with the exception of the area near the fuselage, where they were minimised to enhance the pilot’s downward visibility.
The lower surface of the wing was positioned merely 1.5 m (4.92 ft.) above the ground, creating a favourable ground effect that significantly lowered landing speeds.
The aircraft’s fuel tanks were situated in the central section of the wing on either side of the symmetry axis and could be independently isolated via a multi-way stopcock.
