Blériot-SPAD S.91 explained
The
Blériot-SPAD S.91 was a French light-weight
fighter aircraft. It would be later developed into the
Blériot-SPAD S.510, the last
biplane produced by the French aeronautic industries.
Development
The S.91 was a single-seat single-bay biplane developed towards the end of the 1920s by Blériot in order to meet the requirements of a French government program for a light fighter plane type designated as "Jockey".[1]
The first prototype was flown on 23 August 1927. It featured a wooden fuselage of monocoque construction and metal wings skinned in fabric. This prototype was destroyed in a crash and a second prototype followed. Even after the French government dropped interest in the program seeking a light fighter for the French Air Force, André Herbemont designed a further prototype with an inverted sesquiplane wing configuration.
Operational history
Despite flight demonstrations in Romania and Greece no orders followed. André Herbemont would use his experience with the S.91 prototypes in order to develop the S.510, another biplane fighter which would go into production and would be later used by the French Air Force.
In 1936 at least one of the surviving S.91 prototypes ended up in the Spanish Republican Air Force.[2]
Variants
- S.91 Leger:Powered by a 500abbr=onNaNabbr=on Hispano-Suiza 12Hb V-12 water-cooled engine with twin-leg radiators mounted on the undercarriage, (1 built).[3]
- S.91/1:The S.91 Leger fitted with a frontal radiator design.
- S.91/2:The S.91/1 prototype fitted with a 500abbr=onNaNabbr=on Hispano-Suiza 12Gb W-12 water-cooled engine. It was displayed in Romania and Greece.[4]
- S.91/3:The S.91/2 was fitted with a 420abbr=onNaNabbr=on Gnome-Rhône 9A Jupiter nine-cylinder air-cooled radial engine, (1 built).[5]
- S.91/4:The S.91 Leger, fitted with a 500abbr=onNaNabbr=on Hispano-Suiza 12Mb V-12 engine, flew again on 4 July 1930 with some modifications, including radiators mounted on top of the upper wing.[6]
- S.91/5:The sole S.91/3, fitted with a 480abbr=onNaNabbr=on Gnome-Rhône 9Ae Jupiter, which crashed on the day of its first flight killing the pilot.[7]
- S.91/6:This S.91/4 conversion flew in November 1930 and differed from the prototype in having rounded wingtips, a lengthened fuselage and a tailplane lowered to the fuselage base. Later the tailplane was restored to its former position.[8]
- S.91/7:A new prototype with inverted sesquiplane wing configuration in which only the lower wing had ailerons. It flew on 23 December 1931 and was fitted with a 500abbr=onNaNabbr=on Hispano-Suiza 12Mc V-12 engine. On 2 June 1932 this plane established a record of in a closed-circuit.[9]
- S.91/8:The S.91/7 prototype fitted with a supercharged Hispano-Suiza 12Xbrs engine and a variable-pitch Ratier propeller made its maiden flight on 20 August 1932. This version is reported to have achieved a speed of .[10] [11]
- S.91/9:The S.91/8 became a testbed for Hispano-Suiza's engine-mounted cannon, after being leased to the company in December 1932. Besides the cannon it was also fitted with a large-diameter Levasseur fixed-pitch propeller.[12]
Operators
- Spain
Bibliography
- Cortet. Pierre . Les chasseurs SPAD-Herbemont de l'entre-deux guerres. Avions: Toute l'Aéronautique et Son Histoire . March 2001 . 96 . 8–12 . The SPAD-Herbemont Fighters Between the Wars. fr . 1243-8650.
- Cortet. Pierre . Les chasseurs SPAD-Herbemont de l'entre-deux guerres. Avions: Toute l'Aéronautique et Son Histoire . April 2001 . 97 . 42–46. fr . 1243-8650.
Further reading
- Book: Taylor. John W. R.. Alexander. Jean. Combat Aircraft of the World. 1969. G.P. Putnam's Sons. New York. 130–131.
- Book: Taylor, Michael J. H. . Jane's Encyclopedia of Aviation . 1989 . Studio Editions . London . 164 .
Notes and References
- Web site: Blérriot-SPAD S.91/6. live. 2021-06-21. 1000aircraftphotos.com. https://web.archive.org/web/20141215133335/http://1000aircraftphotos.com/Contributions/PippinBill/11986.htm . 2014-12-15 .
- Web site: Aircraft that took part in the Spanish Civil War . 2014-12-15 . 2015-02-05 . https://web.archive.org/web/20150205085135/http://www.zi.ku.dk/personal/drnash/model/Spain/did.html . dead .
- Web site: Parmentier . Bruno . SPAD S-91 . Aviafrance . 26 February 2018 . Paris . French . 18 April 1999.
- Web site: Parmentier. Bruno. SPAD S-91/2. Aviafrance. 26 February 2018. Paris. French. 18 April 1999.
- Web site: Parmentier . Bruno . SPAD S-91/3 . Aviafrance . 26 February 2018 . Paris . French . 1 August 2001.
- Web site: Parmentier . Bruno . SPAD S-91/4 . Aviafrance . 26 February 2018 . Paris . French . 6 Mar 2001.
- Web site: Parmentier . Bruno . SPAD S-91/5 . Aviafrance . 26 February 2018 . Paris . French . 1 August 2001.
- Web site: Parmentier . Bruno . SPAD S-91/6 . Aviafrance . 26 February 2018 . Paris . French . 28 April 2001.
- Web site: Parmentier . Bruno . SPAD S-91/7 . Aviafrance . 26 February 2018 . Paris . French . 14 April 2000.
- 6 October 1932. Le monoplace de chasse Blériot"91". Les Ailes. 590 . 3.
- Web site: Parmentier . Bruno . SPAD S-91/8 . Aviafrance . 26 February 2018 . Paris . French . 28 April 2001.
- Web site: Parmentier . Bruno . SPAD S-91/9 . Aviafrance . 26 February 2018 . Paris . French . 1 August 2001.