Salmson 2: Difference between revisions
m removed Category:Propeller aircraft using HotCat |
m Replacing old infobox system with Template:Infobox aircraft (via WP:JWB) |
||
(38 intermediate revisions by 21 users not shown) | |||
Line 1: | Line 1: | ||
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. --> |
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. --> |
||
{{Infobox aircraft |
|||
|name= Salmson 2 |
|name= Salmson 2 A.2 |
||
|image= File:Salmson 2 WW1 recon aircraft.jpg |
|image= File:Salmson 2 WW1 recon aircraft.jpg |
||
|caption= |
|caption= |
||
}}{{Infobox Aircraft Type |
|||
|type= [[Reconnaissance]] [[biplane]] |
|type= [[Reconnaissance]] [[biplane]] |
||
|manufacturer= [[Salmson]] |
|manufacturer= [[Salmson]] |
||
|designer= |
|designer= |
||
| |
|first_flight= 1917 |
||
|introduction= |
|introduction= |
||
|retired= |
|retired= |
||
|number_built=3,800+ |
|||
|number built=3,200 |
|||
|status= |
|status= |
||
|primary_user= |
|||
|primary user= |
|||
|more_users= |
|||
|more users= |
|||
|unit cost= |
|unit cost= |
||
|variants |
|variants= |
||
}} |
}} |
||
|} |
|||
The '''Salmson 2''', ( |
The '''Salmson 2 A.2''', (often shortened to '''Salmson 2''') was a French [[biplane]] [[reconnaissance]] aircraft developed and produced by [[Salmson]] to a 1916 requirement. Along with the [[Breguet 14]], it was the main reconnaissance aircraft of the French army in 1918 and was also used by [[American Expeditionary Force]] aviation units. At the end of the [[First World War]], one-third of French reconnaissance aircraft were Salmson 2s. |
||
==Design and development== |
==Design and development== |
||
During the First World War, the Salmson factory built aircraft engines, generally 9- and later 18-cylinder water-cooled radial engines developed from the [[Switzerland|Swiss]] Canton-Unné design, |
During the First World War, the Salmson factory built aircraft engines, generally 9- and later 18-cylinder water-cooled radial engines developed from the [[Switzerland|Swiss]] Canton-Unné design, an early stationary radial engine design used for military aircraft. The company's first aircraft was the [[Salmson-Moineau S.M.1]], an unusual three-seat reconnaissance biplane with twin propellers gear-driven from a single Salmson engine mounted sideways in the fuselage but it was not successful although it saw limited production. |
||
The Salmson 2 |
The Salmson 2 came from a requirement to replace the [[Sopwith 1½ Strutter]] and [[Dorand AR|Dorand A.R.]] reconnaissance aircraft in the A.2 (tactical reconnaissance) role. Salmson had built the 1½ Strutter under license, and the Salmson 2, while an original design, had more in common with the Sopwith than to the Salmson-Moineau. The aircraft was of conventional construction with a two-bay biplane configuration, powered by the company's own {{cvt|230|hp}} [[Salmson 9Z]] water-cooled radial engine. Some minor control problems were quickly resolved in early testing, but the main defect of the Salmson 2, shared with the contemporary [[Airco DH.4]], was that the pilot and gunner were widely separated, making communication difficult. Production was ordered after trials on 29 April 1917, and deliveries were underway by October of that year. Around 3,200 Salmson 2s were built in France, 2,200 by Salmson and the remainder by the [[Latécoère]], [[Hanriot]], and [[Desfontaines]], companies. Some of these were '''Salmson 2 E.2''' dual control advanced training (''Ecole'') aircraft. |
||
[[File:Salmson2.jpg|thumb|Salmson 2]] |
|||
[[File:Salmson 2 Limousine L'Aéronautique October 1921.jpg|thumb|Salmson 2 Limousine photo from L'Aéronautique October 1921]] |
|||
[[File:Lignes Aeriennes Latécoére (Latécoére-Toulouse).jpg|thumb|Salmson 2 Berline of Lignes Aeriennes Latécoére, ''circa ''1918]] |
|||
==Variants== |
==Variants== |
||
Developments of the Salmson 2 included: |
Developments of the Salmson 2 included: |
||
* '''Salmson 2 A.2''' standard model. |
|||
;Salmson 4:an enlarged version fitted with light armour, designed to meet the Ab 2 ground attack role. Limited production in 1918, but cancelled at the end of the war. |
|||
* '''Salmson 2 E.2''' dual control advanced training aircraft. |
|||
;Salmson 5:modified Salmson 2 for A2 role, no production. |
|||
* '''Salmson 4 Ab.2''' was an enlarged version fitted with armour to meet the ground attack role. Production in 1918 was limited, and was cancelled at the end of the war. |
|||
* '''Salmson 5 A.2''' was a modified Salmson 2, with no production. |
|||
;Salmson Limousine: Also known as '''Salmson 2 Berline'''. After the First World War, a number of ex-military Salmson 2s were converted into civilian passenger aircraft. |
|||
* '''Salmson 7 A.2''' was a modified Salmson 2. The primary change was that the pilot and gunner were seated back-to-back in a single cockpit. Large scale production was planned, but was cancelled with the end of the war. |
|||
[[File:Lignes Aeriennes Latécoére (Latécoére-Toulouse).jpg|right|thumb|A Salmson 2 Berline of Lignes Aeriennes Latécoére, circa 1918]] |
|||
* '''Salmson Limousine''' ex-military Salmson 2s converted into enclosed civilian passenger aircraft after the First World War. |
|||
;Kawasaki Army Otsu-1 Reconnaissance Aircraft: Japanese licence-built Salmson 2A.2 reconnaissance aircraft. |
|||
* '''Salmson 2 Berline''' ex-military Salmson 2s converted into open cockpit civilian passenger aircraft after the First World War. |
|||
* '''Kawasaki Army ''Otsu-1'' (乙-1) Reconnaissance Aircraft''' was a Japanese licence-built Salmson 2 A.2. |
|||
==Operational history== |
==Operational history== |
||
In addition to its service with the French army, the Salmson 2 served during the First World War with [[United States]] air units. Some 700 were purchased, and were generally successful. |
In addition to its service with the French army, the Salmson 2 served during the First World War with [[United States]] air units. Some 700 were purchased, and were generally successful. |
||
Postwar Salmson 2s were purchased by [[Czechoslovakia]], and remained in service until 1924. Others were transferred to [[Poland]], but were withdrawn by 1920, and replaced by [[Bristol F.2B]]s. [[Japan]] undertook licensed production as the '''Army Type ''Otsu 1''''', also known as the Kawasaki-Salmson. The number of aircraft built in Japan is unclear; 300 were built by [[Kawasaki Heavy Industries|Kawasaki]], and the same quantity by the [[Imperial Japanese Army]]'s [[Tokorozawa]] supply depot, although the total number of aircraft produced may have been as high as 1,000. |
|||
After First World War, the Salmson 2 A.2 produced by [[Latécoère]] were the first aircraft used by French pioneering airmail company ''[[Aéropostale (aviation)|Aéropostale]]''. |
|||
==Military operators== |
|||
[[File:Otusiki 1gata teisatuki.jpg|thumb|right|300px|<center>Otsu-1 Japanese version</center>]] |
|||
==Military operators== |
|||
===Wartime=== |
===Wartime=== |
||
; {{FRA}} |
; {{FRA}} |
||
*[[French Air Force]] |
* [[French Air Force]] |
||
; {{USA}} |
; {{USA}} |
||
*[[American Expeditionary Force]] |
* [[American Expeditionary Force]] |
||
===Post-war=== |
===Post-war=== |
||
[[File:Otusiki 1gata teisatuki.jpg|thumb|Japanese ''Otsu-1'']] |
|||
; {{BEL}} |
; {{BEL}} |
||
*[[Belgian Air Force]] - One aircraft only. |
* [[Belgian Air Force]] - One aircraft only. |
||
; {{CSK}} |
; {{CSK}} |
||
* [[Czechoslovak Air Force]] |
* [[Czechoslovak Air Force]] |
||
; {{FRA}} |
|||
* [[French Navy]]{{sfn|Morareau|1990|p=15}} |
|||
; {{JPN}} |
; {{JPN}} |
||
*[[Imperial Japanese Army]] |
* [[Imperial Japanese Army]] |
||
;{{flag|Peru}} |
;{{flag|Peru}} |
||
*[[Peruvian Air Force]] - One aircraft only. |
* [[Peruvian Air Force]] - One aircraft only. |
||
; {{POL}} |
; {{POL}} |
||
*[[Polish Air Force]] |
* [[Polish Air Force]] |
||
; {{ESP}} |
; {{ESP}} |
||
*[[Spanish Air Force]] - One aircraft only. |
* [[Spanish Air Force]] - One aircraft only. |
||
; {{RUS}} / {{USSR}} |
; {{RUS}} / {{USSR}} |
||
*[[Soviet Air Force]] |
* [[Soviet Air Force]] |
||
==Aircraft on display== |
|||
==Survivors== |
|||
* Kakamigahara Aerospace Museum, [[Kakamigahara, Gifu]] |
* Kakamigahara Aerospace Museum, [[Kakamigahara, Gifu]] (replica) |
||
* ''[[L'Envol des pionniers|L'Envol des Pionniers]]'', [[Toulouse]], France (replica) |
|||
<gallery mode="packed" caption="Replicas"> |
|||
File:かかみがはら航空宇宙科学博物館 (21174615321).jpg|Replica Salmson 2 A.2/Otsu 1 in Japan. |
|||
File:Replica Salmson 2 A.2 at Envol des pionniers.jpg|Replica Salmson 2 A.2 in Toulouse, France. |
|||
</gallery> |
|||
==Specifications== |
==Specifications== |
||
[[File:Salmson 2 A.2 dwg.jpg|thumb|Salmson 2 |
[[File:Salmson 2 A.2 dwg.jpg|thumb|Salmson 2 A.2 drawing]] |
||
{{aircraft specifications |
|||
{{Aircraft specs |
|||
|plane or copter?=plane |
|||
|ref=French Aircraft of the First World War<ref name=DavillaandSoltan>{{cite book |last1=Davilla |first1=James J. |last2=Soltan |first2=Arthur |title=French Aircraft of the First World War |publisher=Flying Machines Press |location=Mountain View, CA |year=1997 |isbn=978-0-9637110-4-5 |pages=25–26}}</ref> |
|||
|jet or prop?=prop |
|||
|prime units?=met |
|||
|ref=Davilla and Soltan |
|||
<!-- |
|||
|crew=Two, pilot and gunner |
|||
General characteristics |
|||
|capacity= |
|||
--> |
|||
|payload main= |
|||
|crew=2 |
|||
|payload alt= |
|||
|length |
|length m=8.5 |
||
|length |
|length note= |
||
|span |
|span m=11.75 |
||
|span |
|span note= |
||
|height |
|height m=2.9 |
||
|height |
|height note= |
||
|area |
|wing area sqm=37.27 |
||
|area |
|wing area note= |
||
|aspect ratio=<!-- sailplanes --> |
|||
|airfoil= |
|airfoil= |
||
|empty weight |
|empty weight kg=780 |
||
|empty weight |
|empty weight note= |
||
| |
|gross weight kg=1290 |
||
| |
|gross weight note= |
||
|max takeoff weight kg= |
|||
|useful load main= |
|||
|max takeoff weight note= |
|||
|useful load alt= |
|||
|fuel capacity= |
|||
|max takeoff weight main= |
|||
|max takeoff weight alt= |
|||
|more general= |
|more general= |
||
<!-- |
|||
|engine (prop)=[[Salmson 9Za]] |
|||
Powerplant |
|||
|type of prop=radial piston engine |
|||
--> |
|||
|number of props=1 |
|||
|eng1 number=1 |
|||
|power main= 172 kW |
|||
|eng1 name=[[Salmson 9Za]] |
|||
|power alt=230 hp |
|||
|eng1 type=9-cylinder water-cooled radial piston engine |
|||
|power original= |
|||
|eng1 kw=172 |
|||
|max speed main=188 km/h |
|||
|eng1 note= |
|||
|max speed alt= 101 knots, 116 mph |
|||
|max speed more=at sea level |
|||
|prop blade number=2 |
|||
|cruise speed main= |
|||
|prop name=fixed-pitch propeller |
|||
|cruise speed alt= |
|||
|prop dia m=<!-- propeller aircraft --> |
|||
|stall speed main= |
|||
| |
|prop dia note= |
||
<!-- |
|||
|never exceed speed main= |
|||
Performance |
|||
|never exceed speed alt= |
|||
--> |
|||
|range main=500 km |
|||
|max speed kmh=188 |
|||
|range alt= 270 nm, 310 mi |
|||
|max speed note=at sea level |
|||
|ceiling main=6,250 m |
|||
|cruise speed kmh= |
|||
|ceiling alt= 20,500 ft |
|||
|cruise speed note= |
|||
|climb rate main= |
|||
| |
|stall speed kmh= |
||
|stall speed note= |
|||
|loading main= |
|||
|never exceed speed kmh= |
|||
|loading alt= |
|||
|never exceed speed note= |
|||
|range km=500 |
|||
|range note= |
|||
|combat range km= |
|||
|combat range note= |
|||
|ferry range km= |
|||
|ferry range note= |
|||
|endurance=<!-- if range unknown --> |
|||
|ceiling m=6250 |
|||
|ceiling note= |
|||
|climb rate ms= |
|||
|climb rate note= |
|||
|time to altitude={{convert|2,000|m|ft|abbr=on|0}} in 7 minutes 13 seconds<ref name="Owers">{{cite book|last=Owers|first=Colin A. |author2=Jon S. Guttman |author3=James J. Davilla |date=2001 |title=Salmson aircraft of World War I |location=Boulder, CO |url=https://books.google.com/books?id=6XcLAAAACAAJ |publisher=Paladin Press |isbn=1-891268-16-3}}</ref> |
|||
|wing loading kg/m2= |
|||
|wing loading note= |
|||
|fuel consumption kg/km= |
|||
|power/mass= |
|||
|thrust/weight= |
|thrust/weight= |
||
|more performance=<!--</br> |
|||
|power/mass main= |
|||
*'''Take-off run:''' {{cvt||m|0}} |
|||
|power/mass alt= |
|||
*'''Take-off distance to {{cvt|15|m|0}}:''' {{cvt||m|0}} |
|||
|more performance= |
|||
*'''Landing run:''' {{cvt||m|0}} |
|||
*'''Time to altitude:''' {{convert|2,000|m|ft|abbr=on|0}} in 7 minutes 13 seconds<ref name="Owers">{{cite book|last=Owers|first=Colin A. |author2=Jon S. Guttman |author3=James J. Davilla|title=Salmson aircraft of World War I|location=Boulder, Colorado|date=2001|pages=26|isbn=1 891268 16 3}}</ref> |
|||
*'''Landing distance from {{cvt|15|m|0}}:''' {{cvt||m|0}}--> |
|||
|guns=<br> |
|||
<!-- |
|||
Armament |
|||
--> |
|||
|guns=* |
|||
** 1 × forward synchronized 0.303 in [[Vickers machine gun]] |
** 1 × forward synchronized 0.303 in [[Vickers machine gun]] |
||
** 2 × rear, ring-mounted 0.303 in [[Lewis |
** 2 × rear, ring-mounted 0.303 in [[Lewis gun]]s |
||
|bombs= |
|||
|avionics= |
|avionics= |
||
}} |
}} |
||
==References== |
==References== |
||
{{Reflist}} |
|||
{{commons category|Salmson 2}} |
|||
{{reflist}} |
|||
==Bibliography== |
|||
* Davilla, James J., & Soltan, Arthur M., ''French Aircraft of the First World War.'' Stratford, Connecticut: Flying Machines Press, 1997. ISBN 0-9637110-4-0 |
|||
*{{cite journal |last1=Méchin|first1=David|title=Le Salmson 2A2: Bonne surprise sous l'uniforme, Première partie|journal=Le Fana de l'Aviation |date=April 2023 |issue=641 |pages=62–70 |issn=0757-4169 |language=fr|trans-title=The Salmson 2A2: A Pleasant Surprise under the Uniform, Part 1 |name-list-style=amp}} |
|||
*{{cite book|last=Owers|first=Colin A. |author2=Jon S. Guttman |author3=James J. Davilla|title=Salmson aircraft of World War I|location=Boulder, Colorado|date=2001|pages=26|isbn=1 891268 16 3}} |
|||
*{{cite journal |last1=Méchin|first1=David|title=Le Salmson 2A2: Le guerrier de retour au civil|journal=Le Fana de l'Aviation |date=May 2023 |issue=642|pages=68–75|issn=0757-4169|language=fr |trans-title=The Salmson 2A2: The Warrior Returns to Civil Life}} |
|||
* {{cite journal|last=Morareau |first=Lucien |title=Histoire de l'Aviation Embarquée en France: La 4<sup>eme</sup> Flotille, de la reconnaissance au bombardement |journal=Le Fana de l'Aviation |date=February 1990 |issn=0757-4169 |issue=243 |pages=14–17, 19–21 |language=fr }} |
|||
==Further reading== |
|||
{{Commons category|Salmson 2}} |
|||
* {{cite book |editor1-last=Hirschauer |editor1-first=Louis |editor2-last=Dollfus |editor2-first=Charles |title=L'Année Aéronautique: 1919-1920 |date=1920 |publisher=Dunod |location=Paris |page=33 |url=https://gallica.bnf.fr/ark:/12148/bpt6k6553380s/f45.item}} |
|||
{{Salmson aircraft}} |
|||
{{Authority control}} |
|||
[[Category:French military reconnaissance aircraft |
[[Category:1910s French military reconnaissance aircraft]] |
||
[[Category:Military aircraft of World War I]] |
|||
[[Category:Biplanes]] |
[[Category:Biplanes]] |
||
[[Category:Single-engine aircraft]] |
|||
[[Category:Salmson aircraft]] |
[[Category:Salmson aircraft]] |
||
[[Category: |
[[Category:Single-engined tractor aircraft]] |
||
[[Category:Aircraft first flown in 1917]] |
Latest revision as of 01:53, 12 September 2024
Salmson 2 A.2 | |
---|---|
General information | |
Type | Reconnaissance biplane |
Manufacturer | Salmson |
Number built | 3,800+ |
History | |
First flight | 1917 |
The Salmson 2 A.2, (often shortened to Salmson 2) was a French biplane reconnaissance aircraft developed and produced by Salmson to a 1916 requirement. Along with the Breguet 14, it was the main reconnaissance aircraft of the French army in 1918 and was also used by American Expeditionary Force aviation units. At the end of the First World War, one-third of French reconnaissance aircraft were Salmson 2s.
Design and development
[edit]During the First World War, the Salmson factory built aircraft engines, generally 9- and later 18-cylinder water-cooled radial engines developed from the Swiss Canton-Unné design, an early stationary radial engine design used for military aircraft. The company's first aircraft was the Salmson-Moineau S.M.1, an unusual three-seat reconnaissance biplane with twin propellers gear-driven from a single Salmson engine mounted sideways in the fuselage but it was not successful although it saw limited production.
The Salmson 2 came from a requirement to replace the Sopwith 1½ Strutter and Dorand A.R. reconnaissance aircraft in the A.2 (tactical reconnaissance) role. Salmson had built the 1½ Strutter under license, and the Salmson 2, while an original design, had more in common with the Sopwith than to the Salmson-Moineau. The aircraft was of conventional construction with a two-bay biplane configuration, powered by the company's own 230 hp (170 kW) Salmson 9Z water-cooled radial engine. Some minor control problems were quickly resolved in early testing, but the main defect of the Salmson 2, shared with the contemporary Airco DH.4, was that the pilot and gunner were widely separated, making communication difficult. Production was ordered after trials on 29 April 1917, and deliveries were underway by October of that year. Around 3,200 Salmson 2s were built in France, 2,200 by Salmson and the remainder by the Latécoère, Hanriot, and Desfontaines, companies. Some of these were Salmson 2 E.2 dual control advanced training (Ecole) aircraft.
Variants
[edit]Developments of the Salmson 2 included:
- Salmson 2 A.2 standard model.
- Salmson 2 E.2 dual control advanced training aircraft.
- Salmson 4 Ab.2 was an enlarged version fitted with armour to meet the ground attack role. Production in 1918 was limited, and was cancelled at the end of the war.
- Salmson 5 A.2 was a modified Salmson 2, with no production.
- Salmson 7 A.2 was a modified Salmson 2. The primary change was that the pilot and gunner were seated back-to-back in a single cockpit. Large scale production was planned, but was cancelled with the end of the war.
- Salmson Limousine ex-military Salmson 2s converted into enclosed civilian passenger aircraft after the First World War.
- Salmson 2 Berline ex-military Salmson 2s converted into open cockpit civilian passenger aircraft after the First World War.
- Kawasaki Army Otsu-1 (乙-1) Reconnaissance Aircraft was a Japanese licence-built Salmson 2 A.2.
Operational history
[edit]In addition to its service with the French army, the Salmson 2 served during the First World War with United States air units. Some 700 were purchased, and were generally successful.
Postwar Salmson 2s were purchased by Czechoslovakia, and remained in service until 1924. Others were transferred to Poland, but were withdrawn by 1920, and replaced by Bristol F.2Bs. Japan undertook licensed production as the Army Type Otsu 1, also known as the Kawasaki-Salmson. The number of aircraft built in Japan is unclear; 300 were built by Kawasaki, and the same quantity by the Imperial Japanese Army's Tokorozawa supply depot, although the total number of aircraft produced may have been as high as 1,000.
After First World War, the Salmson 2 A.2 produced by Latécoère were the first aircraft used by French pioneering airmail company Aéropostale.
Military operators
[edit]Wartime
[edit]Post-war
[edit]- Belgian Air Force - One aircraft only.
- Peruvian Air Force - One aircraft only.
- Spanish Air Force - One aircraft only.
Aircraft on display
[edit]- Kakamigahara Aerospace Museum, Kakamigahara, Gifu (replica)
- L'Envol des Pionniers, Toulouse, France (replica)
-
Replica Salmson 2 A.2/Otsu 1 in Japan.
-
Replica Salmson 2 A.2 in Toulouse, France.
Specifications
[edit]Data from French Aircraft of the First World War[2]
General characteristics
- Crew: 2
- Length: 8.5 m (27 ft 11 in)
- Wingspan: 11.75 m (38 ft 7 in)
- Height: 2.9 m (9 ft 6 in)
- Wing area: 37.27 m2 (401.2 sq ft)
- Empty weight: 780 kg (1,720 lb)
- Gross weight: 1,290 kg (2,844 lb)
- Powerplant: 1 × Salmson 9Za 9-cylinder water-cooled radial piston engine, 172 kW (231 hp)
- Propellers: 2-bladed fixed-pitch propeller
Performance
- Maximum speed: 188 km/h (117 mph, 102 kn) at sea level
- Range: 500 km (310 mi, 270 nmi)
- Service ceiling: 6,250 m (20,510 ft)
- Time to altitude: 2,000 m (6,562 ft) in 7 minutes 13 seconds[3]
Armament
- Guns: *
- 1 × forward synchronized 0.303 in Vickers machine gun
- 2 × rear, ring-mounted 0.303 in Lewis guns
References
[edit]- ^ Morareau 1990, p. 15.
- ^ Davilla, James J.; Soltan, Arthur (1997). French Aircraft of the First World War. Mountain View, CA: Flying Machines Press. pp. 25–26. ISBN 978-0-9637110-4-5.
- ^ Owers, Colin A.; Jon S. Guttman; James J. Davilla (2001). Salmson aircraft of World War I. Boulder, CO: Paladin Press. ISBN 1-891268-16-3.
Bibliography
[edit]- Méchin, David (April 2023). "Le Salmson 2A2: Bonne surprise sous l'uniforme, Première partie" [The Salmson 2A2: A Pleasant Surprise under the Uniform, Part 1]. Le Fana de l'Aviation (in French) (641): 62–70. ISSN 0757-4169.
- Méchin, David (May 2023). "Le Salmson 2A2: Le guerrier de retour au civil" [The Salmson 2A2: The Warrior Returns to Civil Life]. Le Fana de l'Aviation (in French) (642): 68–75. ISSN 0757-4169.
- Morareau, Lucien (February 1990). "Histoire de l'Aviation Embarquée en France: La 4eme Flotille, de la reconnaissance au bombardement". Le Fana de l'Aviation (in French) (243): 14–17, 19–21. ISSN 0757-4169.
Further reading
[edit]- Hirschauer, Louis; Dollfus, Charles, eds. (1920). L'Année Aéronautique: 1919-1920. Paris: Dunod. p. 33.