Blériot-SPAD S.51

Designed by André Herbemont, the S.51 shared its basic configuration with his other aircraft of the period, being a biplane with a swept upper wing and unswept lower wing, joined by I-shaped interplane struts. Unlike earlier designs, the S.51 used metal construction for the wings.

The prototype S.51 was rejected by the French authorities, but revised versions found export customers in the Polish Air Force, which bought 50 of them, and the Turkish and Soviet air forces which each bought a single example. Another development, the S.51/3, was experimentally fitted with the first controllable-pitch propeller developed in France, also designed by Herbemont.{{cite book |last= Taylor |first= Michael J. H. |title=Jane's Encyclopedia of Aviation |year=1989 |publisher=Studio Editions |location=London |pages=164 }}

;S.51

:Prototype for French evaluation, 1x {{convert|380|hp|kW|abbr=on|disp=flip}} Gnome et Rhône 9Aa radial engine.{{cite web |last1=Parmentier |first1=Bruno |title=SPAD S-51 |url=https://www.aviafrance.com/aviafrance1.php?ID=9601&ID_CONSTRUCTEUR=1231&ANNEE=0&ID_MISSION=0&MOTCLEF= |website=Aviafrance|accessdate=2 March 2018 |location=Paris |language=French |date=4 December 2001}}

;S.51/2

:Refined version exported to Poland, 1x {{convert|420|hp|kW|abbr=on|disp=flip}} Gnome et Rhône 9Ab radial engine.

;S.51/3

:Prototype with variable-pitch propeller.

;S.51/4

:Export version for Turkey and the USSR with two extra machine guns in the wings.

;{{POL}}

• Polish Air Force
• 11th (Kościuszko) Squadron

;{{flagu|Soviet Union|1924}}

• Soviet Air Force – One aircraft, used for tests and trials.

;{{flagu|Spain|1931}}File:Blériot-SPAD_S_51.jpg

• Spanish Republican Air Force{{Cite web |url=http://www.zi.ku.dk/personal/drnash/model/spain/did.html |title=Aircraft that took part in the Spanish Civil War |access-date=10 January 2015 |archive-date=5 February 2015 |archive-url=https://web.archive.org/web/20150205085135/http://www.zi.ku.dk/personal/drnash/model/Spain/did.html |url-status=dead }}

;{{TUR}}

• Turkish Air Force

File:Bleriot-SPAD_S.51_3-view_Aero_Digest_August,1930.png

{{Aircraft specs

|ref=Jane's all the World's Aircraft 1928,{{cite book |title=Jane's all the World's Aircraft 1928 |editor1-last=Grey |editor1-first=C.G. |year=1928 |publisher=Sampson Low, Marston & company, ltd |location=London |page=86c}} Aviafrance:S.51-2{{cite web |last1=Parmentier |first1=Bruno |title=SPAD S-51-2 |url=https://www.aviafrance.com/aviafrance1.php?ID=126&ID_CONSTRUCTEUR=1231&ANNEE=0&ID_MISSION=0&MOTCLEF= |website=Aviafrance|accessdate=2 March 2018 |location=Paris |language=French |date=12 April 2003}}

|prime units?=met

|crew=1

|length m=6.45

|span m=9.47

|height m=3.1

|wing area sqm=24.27

|aspect ratio=

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|empty weight kg=990

|gross weight kg=1360

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|eng1 number=1

|eng1 name=Gnome & Rhône 9Ab Jupiter

|eng1 type=9-cylinder air-cooled radial piston engine

|eng1 hp=420

|prop blade number=2

|prop name=fixed pitch propeller

|prop dia m=

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|max speed kmh=245

|max speed note=at {{cvt|100|m}}

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|roll rate=

|glide ratio=

|climb rate ms=7.2

|time to altitude={{cvt|4000|m}} in 9 minutes

|wing loading kg/m2=52.6

|fuel consumption kg/km=

|fuel consumption lb/mi=

|power/mass={{cvt|0.14925|hp/lb|kW/kg|order=flip}}

|armament=2 × fixed, forward-firing {{cvt|7.7|mm|3}} Vickers machine-guns

}}

{{aircontent

|related=

|similar aircraft=

|lists=

• List of aircraft of the Spanish Republican Air Force
• List of Interwar military aircraft

|see also=

}}

{{Reflist}}

• {{cite journal |last1=Bruner|first1=Georges|title=Fighters a la Francaise, Part One|journal=Air Enthusiast |date=1977|issue=3 |pages=85–95 |issn=0143-5450}}
• {{cite journal |last1=Kotelnikov|first1=V.|last2=Kulikov|first2=V.|last3=Cony|first3=C.|name-list-style=amp |title=Les avions français en URSS, 1921–1941 |journal=Avions: Toute l'Aéronautique et son histoire |date=November 2001 |issue=104 |pages=37–43 |trans-title=French Aircraft in the USSR, 1921–1941 |language=fr |issn=1243-8650}}

{{Commons category-inline|Blériot-SPAD S.51}}

{{SPAD aircraft}}

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Category:1920s French fighter aircraft

Category:Blériot aircraft

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Category:Aircraft first flown in 1924