The Bleriot SPAD 91 was originally designed to the requirements of the 1926 lightweight fighter specification which called for an armament of two machine guns and a range of 400km. An all-metal fabric-covered single-seat single-bay biplane with wings of equal span and chord, the first prototype, referred to as the Type 91 Leger (Light), was powered by a 500hp Hispano-Suiza HS 12Hb 12-cylinder water-cooled engine with radiators mounted on the main undercarriage legs. Flown for the first time on 23 August 1927, the Type 91 Leger was followed by a second prototype, the Type 91-1, which differed primarily in having a frontal radiator in place of the twin leg-mounted radiators. This second prototype was subsequently fitted with a 500hp HS 12Gb 12-cylinder engine of W configuration as the Type 91-2, flying in this form on 31 August 1928. After demonstrations in Romania and Greece, it was again re-engined as the Type 91-3 with a 420hp Gnome-Rhone Jupiter 9As nine-cylinder air-cooled radial. Early in 1931 it received a 480hp Gnome-Rhone Jupiter 9Ae as the Type 91-5, but was destroyed on 10 May after six hours flying in the latter form. The original Type 91 Leger had meanwhile been fitted with a 500hp HS 12Mb engine and, with various minor modifications, became the Type 91-4, which first flew on 4 July 1930. Rounded wingtips were then applied, the fuselage was lengthened and the tailplane was lowered to the base of the fuselage, flight testing being resumed on 10 November 1931 as the Type 91-6. The tailplane was later restored to its original position, but both the 1926 and subsequent lightweight, or “Jockey”, fighter programmes had meanwhile been abandoned and none of the competing designs had been ordered into production.

Type 91 Leger (Light)
Engine: 500hp Hispano-Suiza HS 12Hb 12-cylinder

Type 91-1
Engine: 500hp Hispano-Suiza HS 12Hb 12-cylinder
Take-off weight: 1465 kg / 3230 lb
Empty weight: 1161 kg / 2560 lb
Wingspan: 8.65 m / 28 ft 5 in
Length: 6.52 m / 21 ft 5 in
Height: 2.94 m / 10 ft 8 in
Wing area: 20.00 sq.m / 215.28 sq ft
Max. speed: 278 km/h / 173 mph

Type 91-2
Engine: 500hp HS 12Gb 12-cylinder engine

Type 91-3
Engine: 420hp Gnome-Rhone Jupiter 9As nine-cylinder

Type 91-4
Engine: 500hp HS 12Mb

Type 91-5
Engine: 480hp Gnome-Rhone Jupiter 9Ae

Type 91-6

The Type 71 was, like the Type 41, a single-seat derivative of the 1918 SPAD S.XX two-seater, but was intended specifically to participate in the Spanish Concurso de aviones which was to result in the selection of combat aircraft for the Aeronautica Militar Espanola from competing indigenous and foreign types. A staggered single-bay biplane with a sweptback upper wing and unswept lower wing, the Bleriot SPAD 71 was powered by a 300hp Hispano-Suiza HS 8Fb eight-cylinder water-cooled engine, carried an armament of twin 7.7mm MAC (Vickers) machine guns and was flown to Spain for evaluation in January 1923. In the fighter contest it was beaten by the Nieuport 29 and no further development was undertaken.

S.71
Engine: 1 x 300hp Hispano-Suiza 8Fb
Take-off weight: 1306 kg / 2879 lb
Empty weight: 867 kg / 1911 lb
Wingspan: 8.72 m / 29 ft 7 in
Length: 7.30 m / 24 ft 11 in
Height: 2.80 m / 9 ft 2 in
Wing area: 30.00 sq.m / 322.92 sq ft
Max. speed: 237 km/h / 147 mph
Cruise speed: 207 km/h / 129 mph
Ceiling: 6900 m / 22650 ft
Crew: 1
Armament: 2 x 7.7mm

Developed in parallel with the Type 51, the Bleriot SPAD 61 was flown before the 51, the prototype being tested first on 6 November 1923. A single-bay staggered biplane with fabric-covered metal wings and a wooden monocoque fuselage, it was powered by a 12-cylinder W-type Lorraine-Dietrich LO 12Ew engine of 450hp. Production orders were placed on behalf of both Poland (250) and Romania (100), for the Type 61-2, which appeared in 1925, armed with two synchronised 7.7mm MAC (Vickers) machine guns.
A further 30 Bleriot SPAD 61-2s were built under licence in Poland from 1927 by CWL (Centralne Warsztaty Lotnicze) and its successor PZL (Panstwowe Zaklady Lotnicze).
Variants that progressed no further than the prototype stage included the Type 61-3 which reverted to the metal wing structure of the original Type 61-1 (the production Type 61-2 having a wooden wing), and had four 7.7mm Darne machine guns and increased fuel tankage. First flown on 9 May 1925, it was intended to participate in the 1925 fighter trials. Re-engined with a 480hp Lorraine- Dietrich LO 12Ee, it flew on 6 June 1925 as the Type 61-4. Three examples of the Type 61-5 were built, powered by the 450hp Hispano-Suiza HS 12Gb engine. The first of these was flown on 13 May 1925, and one was supplied to Turkey. The second Type 61-5 flew on 9 September 1927 as the Type 61-8 after being re-engined with a 500hp HS 12Hb engine, and the final fighter derivative was the Type 61SES built for Polish evaluation. This differed from earlier models in being a sesquiplane with a swept upper wing. The Type 61SES was flown on 1 May 1926, but proved to have inferior characteristics to those of the standard Type 61-2.

S.61-2
Engine: 1 x 450hp Lorraine 12 Eb
Take-off weight: 1565 kg / 3450 lb
Empty weight: 1055 kg / 2326 lb
Wingspan: 9.61 m / 32 ft 6 in
Length: 6.78 m / 22 ft 3 in
Height: 2.80 m / 9 ft 2 in
Wing area: 29.30 sq.m / 315.38 sq ft
Max. speed: 238 km/h / 148 mph
Cruise speed: 220 km/h / 137 mph
Ceiling: 7500 m / 24600 ft
Range: 400 km / 249 miles
Crew: 1
Armament: 2 x 7.7mm

On 24 December 1925, the Societe Bleriot-Aeronautique received a French government order for three prototypes of a two-seat fighter powered by a 420hp Gnome-Rhone Jupiter 9Ab nine-cylinder radial engine. Designated Bleriot SPAD 60, the fighter was a single-bay biplane of mixed construction with sweptback upper wing and unswept lower wing, armament comprising two fixed forward-firing 7.7mm machine guns in the upper wing and two weapons of similar calibre on a ring mounting in the rear cockpit. The first prototype was flown on 26 June 1926, but as a result of stability problems development was abandoned in favour of the Bleriot SPAD 70.

S.60
Engine: 1 x 420hp Gnome & Rhone Jupiter
Take-off weight: 1803 kg / 3975 lb
Empty weight: 1224 kg / 2698 lb
Wingspan: 11.30 m / 37 ft 1 in
Length: 6.88 m / 23 ft 7 in
Height: 3.21 m / 11 ft 6 in
Wing area: 36.60 sq.m / 393.96 sq ft
Max. speed: 209 km/h / 130 mph
Cruise speed: 185 km/h / 115 mph
Rate of climb: 256 m/min / 850 ft/min
Crew: 2
Armament: 4 x 7.7mm

Designed by Andre Herbemont and of generally similar configuration to the Type 41, the Bleriot SPAD 51 had fabric-covered metal wings and a wooden monocoque fuselage, power being provided by a 420hp Gnome- Rhone Jupiter nine-cylinder radial.
The first prototype, the Type 51-1, was flown on 16 June 1924, a second modified prototype, the Type 51-2, following on 18 March 1925. Powered by a Jupiter IV and carrying an armament of two 7.7mm MAC (Vickers) guns in the upper wing, the Bleriot SPAD 51-2 was ordered for the Polish air arm, the Lotnictwo Wojskowe, 50 being delivered during 1925-26.
Another prototype, the Type 51-3, with an improved propeller, flew on 7 September 1926. This offered a 12km/h speed superiority and improved ceiling over the 51-2. On 30 August 1928 the Type 51-4 final derivative with a special 600hp version of the Jupiter first flew.
Of ten production Type 51-4s were completed, one being sold to Turkey and another to the Soviet Union, these having provision for two fuselage-mounted Vickers and two wing-mounted Darne machine-guns, and a 420hp Jupiter 9Ab.

S.51-2
Engine: 1 x 420hp Gnome & Rhone 9Ab Jupiter
Take-off weight: 1360 kg 2998 lb
Empty weight: 990 kg / 2183 lb
Wingspan: 9.47 m / 31 ft 1 in
Length: 6.45 m / 21 ft 2 in
Height: 3.10 m / 10 ft 2 in
Wing area: 24.27 sq.m / 261.24 sq ft
Max. speed: 245 km/h / 152 mph
Cruise speed: 225 km/h / 140 mph
Ceiling: 8850 m / 29050 ft
Rate of climb: 444 m/min / 1450 ft/min
Armament: 2 x 7.7mm
Crew: 1

The first fighter in the SPAD line to receive the Bleriot SPAD designation was the Bleriot SPAD 41, designed by Andre Herbemont and essentially a single-seat derivative of the SPAD S.XX two-seater of 1918. Powered by a 300hp Hispano-Suiza HS 8Fb eight-cylinder water-cooled engine with two individual Lamblin radiators in place of the familiar circular frontal radiator, the Bleriot SPAD 41 was a staggered single-bay biplane with a sweptback upper wing and unswept lower wing. It featured a wooden monocoque fuselage.
The prototype first flew at Buc on 17 July 1922, but official evaluation revealed an inadequate service ceiling and no production was ordered, the aircraft subsequently being modified for racing.

S.41
CREW 1
Engine: 1 x 300hp Hispano-Suiza 8Fb
Take-off weight: 1307 kg / 2881 lb
Empty weight: 887 kg / 1956 lb
Wingspan: 8.68 m / 29 ft 6 in
Length: 6.65 m / 22 ft 10 in
Height: 2.76 m / 9 ft 1 in
Wing area: 26.40 sq.m / 284.17 sq ft
Max. speed: 238 km/h / 148 mph
Cruise speed: 205 km/h / 127 mph
Ceiling: 6850 m / 22450 ft
Armament: 2 x 7.7mm

The Bleriot-SPAD 33 was first flown on 12 December 1920.