Caudron R.11

{{Lead too short|date=August 2021}}{{Short description|French WW1 fighter aircraft}}  {{Infobox aircraft |name=R.XI |image=Caudron R.11 - Front.jpg |type=Heavy fighter |manufacturer=Caudron |designer=Paul Deville<ref name=Davilla167/> |first_flight=1916<ref name=Davilla168>Davilla, 1997, p.168</ref> |introduction=1918<ref name=Davilla168/> |retired=July 1922 |primary_user=France |produced=1917-1918 |number_built=370 |developed_from=Caudron R.4 |variants= }}

thumb|Caudron R.XI posed for official type photos, showing large balanced rudder and fin. The '''Caudron R.11''' (or '''R.XI''' in contemporary usage), was a French three-seat twin-engine long range escort fighter biplane developed and produced by Caudron during the First World War.<ref name=Davilla168/>

==Development== The R.XI was intended to fulfill a French Corps d'Armee requirement for a long range three-seat escort fighter. Its design was similar to the Caudron R.4, but without a nose-wheel, and with longer wings and fuselage, with two bracing bays outboard the engines rather than three, along with a much larger tail. Hispano-Suiza 8Ba liquid-cooled V-8 engines were housed in streamlined nacelles just above the lower wing, fitted with frontal radiators, which replaced the air-cooled Renault engines used in the R.4.

==Operational history== Production of the 1000 R.XIs ordered by the French Army began in 1917, with the first aircraft completed late in that year.<ref name=Davilla167>Davilla, 1997, p.167</ref>

The first escadrille, R 46, was equipped with the type in February 1918 and the last escadrille to form was R 246,<ref name=Davilla169/> before the Armistice resulted in an abrupt end to production, at which point approximately 370 aircraft had been completed by Caudron, Régy Frères and Gremont.<ref name=Davilla167/>

==Variants== ;Caudron R.XI C.3 : Heavy escort fighter with {{cvt|215|hp|order=flip}} Hispano-Suiza 8Bda engines.

;Caudron R.XII C.3 :R.XI with the more powerful {{cvt|300|hp|order=flip}} Hispano-Suiza 8Fb engines that were expected to boost performance. Sources differ, but it may have had a slightly increased wing area, to {{cvt|60|m2}} and an extra wing bay was added outboard of the engines. It first flew in November 1918 but was still undergoing testing in mid-1919 and no production followed despite plans to equip 12 escadrilles.<ref name=Davilla170>Davilla, 1997, p.170</ref>

;Caudron R.XIV Ca.3 :Similar to the R.XII, but armed with a {{cvt|37|mm}} Hotchkiss cannon in addition to the normal complement of 5 machine guns, and with further increased wing area, to {{cvt|63|m2}}, and a larger, unbalanced rudder. A single example was built following the conversion of an R.XI to carry the cannon in August 1918.<ref name=Davilla170/>

==Operators== thumb|R.XI nose and engine nacelle detail ;{{FRA}} *French Air Force **Escadrille R 46<ref name=Davilla169>Davilla, 1997, p.169</ref> **Escadrille R 239<ref name=Davilla169/> **Escadrille R 240<ref name=Davilla169/> **Escadrille R 241<ref name=Davilla169/> **Escadrille R 242<ref name=Davilla169/> **Escadrille R 246<ref name=Davilla169/>

;{{UK}} *Royal Air Force received two examples for evaluation as a bomber.<ref name=Davilla169/>

;{{USA}} *American Expeditionary Force received two examples for evaluation, and two others were detached to US units.<ref name=Davilla169/>

==Specifications (Caudron R.XI C.3)== thumb|Caudron R.11 drawing {{Aircraft specs |ref=Davilla, 1997, p.168 |prime units?=met  |crew=3 |length m=11.22 |upper span m=17.92 |lower span m=16.97 |height m=2.8 |wing area sqm=54.25 |airfoil= |empty weight kg=1422 |gross weight kg=2165 |fuel capacity={{cvt|220|L|impgal USgal}}<ref name=Green>Green and Swanborough 1994, p.111.</ref><ref name=JAWA1919>{{cite book|last=Grey |first=C.G.|title=Jane's all the World's Aircraft 1919 |edition=Facsimile |year=1969 |publisher=David & Charles (Publishers) Limited |location=London |isbn=0715346474|page=224a}}</ref>  |eng1 number=2 |eng1 name= Hispano-Suiza 8Bda |eng1 type=V-8 water-cooled piston engines |eng1 hp=215 |prop blade number=2 |prop name=wooden fixed pitch propellers |prop dia m=  |max speed kmh=190 |max speed note=at sea level<ref name=Green/><br> :*{{cvt|183|km/h}} at {{cvt|2000|m}} :*{{cvt|178|km/h}} at {{cvt|3000|m}} :*{{cvt|173|km/h}} at {{cvt|4000|m}} :*{{cvt|164|km/h}} at {{cvt|5000|m}} |range km=600 |endurance=3 hours |ceiling m=5950 |time to altitude=<br> :*{{cvt|2000|m}} in 8 minutes 10 seconds :*{{cvt|3000|m}} in 14 minutes 30 seconds :*{{cvt|4000|m}} in 22 minutes 30 seconds :*{{cvt|5000|m}} in 39 minutes |wing loading lb/sqft=8.18 |wing loading note=<ref name=Flight1919>French aeroplanes in service at the front, 1919, p.204</ref> |power/mass={{cvt|11.00|hp/lb|order=flip}}<ref name=Flight1919/> This power to weight is wrong.

|guns=5 x {{cvt|7.7|mm|3}} Lewis machine guns }}  {{aircontent  |related= *Caudron R.6  |similar aircraft= *SPAD SA.3 *Ponnier P.1 |lists= |see also= }}

==References== {{Commons category}}

===Notes=== {{Reflist}}

==Bibliography== *{{cite magazine|last1=Cony|first1=Christophe|title=Aviateur d'Observation en 14/18 (3ème partie et fin)|magazine=Avions: Toute l'aéronautique et son histoire|date=August 1997 |issue=53 |pages=16–21 |trans-title=Aircraft observers in 1914-1918 (third and final part)|language=French |issn=1243-8650}} *{{cite book|last1=Davilla|first1=J. J.|last2=Soltan|first2=A.|title=French Aircraft of the First World War|publisher=Flying Machines Press|location=Mountain View, CA|year=1997|isbn=978-1891268090}} *{{cite magazine|author=|editor-last=|editor-first=|title=French aeroplanes in service at the front|magazine=Flight|date=13 February 1919|page=204}} *{{cite book|last=Green|first=W.|author2=Swanborough, G|title=The Complete Book of Fighters|year=1994|location=New York|publisher= Smithmark |isbn= 0-8317-3939-8}} *{{cite book|last=Owers|first=Colin A. |title=Caudron R.11|series=Windsock Datafile No. 161|publisher=Albatros Productions|year=2013|isbn=978-1906798338}}

R011 Category:Biplanes Category:1910s French fighter aircraft Category:Aircraft first flown in 1916