The Bleriot-SPAD S.510 biplane was designed in 1930, based on the experimental SPAD S.91 model, as a single-seat fighter for the French Air Force. The prototype S.510.01 made its first flight on January 6, 1933. It featured a fuselage with an oval cross-section, constructed from steel and duralumin, with its monocoque tail section also made of duralumin.
Design Features and Maiden Flight
The wings, of equal span, were all-metal with fabric covering and featured standard single streamlined I-type vertical struts on each side, characteristic of Herbemont. Only the upper wing had sweep, and ailerons were installed on both the upper and lower wings. The V-shaped Hispano-Suiza 12Xbrs engine was fitted with a front radiator. The main landing gear struts were streamlined, and the wheels were covered by fairings. The pilot’s open cockpit was located just below a cutout in the trailing edge of the upper wing.
As a result of flight tests, the fuselage was lengthened to improve directional and longitudinal stability, and the ailerons were modified to enhance lateral control. However, the low-wing monoplane Dewoitine D.500 surpassed the S.510 in speed and thus won the project competition. Nevertheless, ace pilot Louis Massot, demonstrating the S.510 to the French Air Minister, General Denain, effectively showcased the biplane’s unparalleled maneuverability and rate of climb.
Flight Trials and Initial Order
Consequently, an order for 60 such aircraft was received in August 1935. The S.510 series models were equipped with four 7.5 mm Chatellerault machine guns, located in small gondolas of faired cutouts under the lower wing.
Armament and Wartime Role
By the beginning of World War II, the S.510s had already been transferred to flight schools and local air defense squadrons, organized to protect industrial facilities and cities in the rear. There is no official information about their participation in combat operations.
Technical Specifications
| Modification | S.510 |
| Wingspan, m | 8.84 |
| Length, m | 7.46 |
| Height, m | 3.41 |
| Wing area, m2 | 22.00 |
| Empty weight | 1250 |
| Normal takeoff weight | 1677 |
| Engine type | 1 Piston engine Hispano-Suiza 12Xbrs |
| Power, hp | 1 x 690 |
| Maximum speed, km/h | 372 |
| Cruising speed, km/h | 324 |
| Practical range, km | 875 |
| Maximum rate of climb, m/min | 890 |
| Practical ceiling, m | 10500 |
| Crew, crew members | 1 |
| Armament | four 7.5-mm MAC-1934 machine guns in underwing gondolas |
Image and diagram gallery of the Bleriot-SPAD S.510
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |
 S.510 |