{{Short description|1915 German reconnaissance aircraft}} <!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. --> {{Infobox aircraft |name= C.I |image= Aviatik C.I.jpg |caption= Aviatik C.I trainer (late series) |type= [[Reconnaissance aircraft]] |manufacturer= [[Aviatik]] |designer= |first_flight= 1915 |introduction= 1915 |retired= 1917 |status= |primary_user= |more_users= |produced= |number_built= |variants= }}

The '''Aviatik C.I''' was an [[aerial reconnaissance|observation]] aircraft designed and produced by the German aircraft manufacturer [[Aviatik]]. It was the first aircraft produced by the company to be mass-produced as well as one of the first German military aircraft of the [[First World War]] to become fairly well known amongst the general public of the era.<ref name="Gray and Thetford p. 59">Gray and Thetford 1962, p. 59.</ref>

It was a development of the [[Aviatik B.I]] and [[Aviatik B.II|B.II]] models, being one of first aircraft of the new German C class of armed [[biplane]]s. On the C.I, the observer sat in front of the pilot; this arrangement was unique amongst the C class, which opted to place the pilot in the forward position instead.<ref name="Gray and Thetford p. 59"/> The positions of the pilot and observer were reversed in last series of 50, ordered in 1917 solely for [[training aircraft|training]] purposes.<ref name=grosz5>Grosz 1997, pp. 5-6.</ref> There was only a single aircraft completed of the refined ''C.Ia'' version in May 1916, with armament still in a forward cab, serving as a prototype for the C.III.<ref name=grosz5/>

Operationally, the C.I was introduced in 1915; it was typically flown in flights of three to six aircraft; the destruction of one aircraft on 7 November 1915 was considered a such a feat that the [[Royal Flying Corps]] pilot responsible was awarded the [[Victoria Cross]].<ref name="Gray and Thetford p. 62">Gray and Thetford 1962, p. 62.</ref> In response to demands for greater performance, Aviatik developed several derivatives of the aircraft, including the [[Aviatik C.II]] and the [[Aviatik C.III|C.III]], which were equipped with more powerful engines and various refinements, although the airframes would typically have little modification. 548 Aviatik C.I were built in total: 402 by Aviatik (including 51 trainers and 1 C.Ia) and 146 by Hannover.<ref name=grosz532>Grosz 1997, pp. 5-6, 32.</ref>

==Design and development== Prior to the outbreak of the [[First World War]], the German aircraft manufacturer [[Aviatik]] had built up a favourable relationship for its early aircraft.<ref name="Gray and Thetford p. 59"/> Following the start of the conflict, the company quickly turned its attention to Germany's wartime needs. The resulting aircraft from this endeavour, designed ''C.I'', was the company's first aircraft be produced on a large scale.<ref name="Gray and Thetford p. 59"/> Developed during late 1914 and early 1915, the C.I was powered by a single [[Mercedes D.III]] six-cylinder in-line piston engine and armed with a single [[machine gun]] for self-defence purposes. The latter was operated by the aerial observer and clipped on a sliding mounting fitted on a rail at either side of the cockpit; a quick-release mechanism allowed for it to be readily swapped from one side of the cockpit to the other as required.<ref name="vW">van Wyngarden 2006, p. 6.</ref><ref name="Gray and Thetford p. 59"/> Unusually amongst German aircraft of the era, the observer was positioned in front of the pilot; this arrangement restricted the range of fire of the machine gun along with the field of vision for performing observations. Due to these shortcomings, the seating arrangement was reversed on later-built aircraft.<ref name="Gray and Thetford p. 59"/>

In terms of its construction, the C.I was relatively orthodox for the era.<ref name="Gray and Thetford p. 59"/> The fuselage had a box-girder structure comprising four [[spruce]] [[longeron]]s and members that were [[Bracing (aeronautics)|braced]] using stranded [[steel]] cables. It had a rounded top decking that tapered towards the rear to form a vertical knife-edge while the forward end terminated in a sheet plate that was fretted with lightening holes.<ref name="Gray and Thetford pp. 5960">Gray and Thetford 1962, pp. 59-60.</ref> This plate, in conjunction with the first two formers, supported the engine bearers, which were further braced sing steel tubing. The engine was surrounded by curved [[aluminium]] panels, although the cylinder block remained exposed; aluminium sheeting also covered the sides and underside of the nose while the majority of the fuselage was covered by [[fabric]].<ref name="Gray and Thetford p. 60"/> The [[exhaust manifold]] was an obstruction to forward visibility. Early-build C.Is had their [[Radiator (engine cooling)|radiator]]s, however, the majority of aircraft were fitted with an improved Teeves and Braun-built unit that was mounted on the front of the center-section wing [[strut]]s.<ref name="Gray and Thetford p. 60">Gray and Thetford 1962, p. 60.</ref>

The wings were rectangular, covered with fabric, and comprised all-wood construction except for the compression struts, which were made of steel tubing.<ref name="Gray and Thetford p. 60"/> The primary [[spar (aeronautics)|spars]] were produced in two halves and joined together with hardwood tongues to form hollow box-spars; the [[trailing edge]] of the wing formed its characteristic scalloped outline. A set of unbalanced parallel-[[Chord (aeronautics)|chord]] were hinged directly to the rear spar at the upper wing tips.<ref name="Gray and Thetford p. 60"/> The inverted trestle-type [[cabane strut]] and every interplane strut was composed of [[streamliner|streamlined]] steel tubing and braced with stranded wires. The interplane bay featured unusual bracing, the forward wire being anchored to the rear spar junction of the fuselage while the rear wire was anchored to the inner struts and terminally anchored to the top longeron; this arrangement proved superior for the use of the aircraft's machine gun.<ref name="Gray and Thetford p. 60"/>

A typical V-shaped [[landing gear|undercarriage]] was used, the struts of which joined with a compact horizontal tube at its apex that functioned as the anchor point for a rubber chord that acted as a [[shock absorber]].<ref name="Gray and Thetford p. 61"/> The undercarriage was braced by stranded cables between the front legs while an elliptical tube spreader-bar joined the legs forward of the axle and a wire strained connected them behind the axle. Almost all of the tail surfaces, save for the wooden tail plane ribs, were composed of light-gauge steel tubing.<ref name="Gray and Thetford p. 61"/> The tailplane had a distinctive [[kidney]] shape while the [[rudder]], which was balanced, had a [[comma]] shape. A lengthy and narrow triangular [[fin]] was also present, which was braced to the tailplane via a light steel strut; the underside of the tailplane was itself braced to the fuselage by a pair of light struts.<ref name="Gray and Thetford p. 61">Gray and Thetford 1962, p. 61.</ref>

During 1916, in response to military demands for superior performance, Aviatik developed the improved [[Aviatik C.III|C.III]].<ref name="Gray and Thetford p. 61"/> It was a refined C.I, having cleaned up nose contours, a redesigned exhaust manifold, a new [[aerofoil]]-style radiator and an enlarged spinner fitted to the propeller. The wingspan was also reduced along with the chord of the ailerons, the fuel system was improved; however, the airframe was virtually identical to that of the C.I.<ref name="Gray and Thetford p. 61"/> These changes resulted in the C.III being 18 kmph faster than its predecessor while also improving its forward visibility considerably.<ref name="Gray and Thetford p. 61"/>

==Variants== ;C.I :Primary model ;C.I(Han) :Primary model licence-built by Hannover, initially designated Hannover C.I ;C.I trainer :Last series of 50 plus a prototype manufactured in 1917, with a machine gun in rear cab.<ref name=grosz5/> ;C.Ia :Prototype for C.III, flown in May–June 1916.<ref name=grosz5/> ;C.II :This model was powered by a 149 kW (200 hp) [[Benz Bz.IV]] engine. it was not produced in quantity.<ref name="Taylor 88">''Janes'' 1989, p. 88.</ref> ;C.III :The C.III was a 1916 refinement which was operated until 1917.<ref name="Taylor 88"/>

==Operators== ;{{flag|Austria-Hungary}} * [[KuKLFT]] ;{{flag|German Empire}} * [[Luftstreitkrafte]] ;{{ROM}} * [[Romanian Air Corps]] ;{{flag|Kingdom of Yugoslavia}} * [[Royal Yugoslav Air Force]] - Postwar

==Specifications== {{Aircraft specs |ref= ''German Aircraft of the First World War''<ref name="Gray and Thetford pp. 5963">Gray and Thetford 1962, pp. 59-63.</ref> |prime units?= met <!-- General characteristics --> |crew= Two |length m= 7.925 |length note= |span m= 12.5 |span note= |height m= 2.95 |height note= |wing area sqm= 43 |wing area note= |aspect ratio=<!-- sailplanes --> |airfoil=<!--'''root:''' [[NACA airfoil|NACA ]]; '''tip:''' [[NACA airfoil|NACA ]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>--> |empty weight kg= 750 |empty weight note= |gross weight kg= 1,340 |gross weight note= |max takeoff weight kg= |max takeoff weight note= |fuel capacity= |more general= <!-- Powerplant --> |eng1 number= 1 |eng1 name= [[Mercedes D.III]] |eng1 type= six-cylinder water-cooled in-line piston engine |eng1 kw= 119 |eng1 note=

|prop blade number= 2 |prop name= fixed-pitch propeller |prop dia m=<!-- propeller aircraft --> |prop dia note= <!-- Performance --> |max speed kmh= 142 |max speed note= |cruise speed kmh= |cruise speed note= |stall speed kmh= |stall speed note= |never exceed speed kmh= |never exceed speed note= |range km= |range note= |combat range km= |combat range note= |ferry range km= |ferry range note= |endurance= Three hours |ceiling m= 3,500 |ceiling note= |g limits=<!-- aerobatic --> |roll rate=<!-- aerobatic --> |climb rate ms= |climb rate note= |time to altitude={{cvt|1000|m}} in 12 minutes |wing loading kg/m2= 31.2 |wing loading note= |fuel consumption kg/km= |power/mass={{cvt|0.089|kW/kg}} |more performance= <!-- Armament --> |guns= 1x [[Parabellum MG14]] mounted on cockpit side rails |bombs= |avionics= }}

==References== ===Citations=== {{Reflist}}

===Bibliography=== * {{cite book |last1 = Gray |first1 = Peter |first2 = Owen |last2 = Thetford |title = German Aircraft of the First World War |publisher = Putnam |location = London, UK |year = 1970 |edition = Second |isbn = 0-370-00103-6}} * {{cite book |last1 = Grosz |first1 = Peter M. |title = Windsock Datafile no. 63. |chapter = Aviatik C.I |location = Berkhamsted |publisher = Albatros Productions |date = 1997 |ISBN = 0-948414-95-2}} * {{cite book |last1=Herris |first1=Jack |title=Aviatik Aircraft of WWI: A Centennial Perspective on Great War Airplanes |date=2023 |isbn=978-1-953201-59-1 |publisher=Aeronaut Books |location= |series=Great War Aviation Centennial Series |volume=10 |edition=2nd}} * {{cite journal |last1=Klaauw |first1=Bart van der |title=Unexpected Windfalls: Accidentally or Deliberately, More than 100 Aircraft 'arrived' in Dutch Territory During the Great War |journal=Air Enthusiast |date=March–April 1999 |issue=80 |pages=54–59 |issn=0143-5450}} * {{cite book |last = van Wyngarden |first = G. |title = Early German Aces of World War 1 |location = Oxford |publisher = Osprey Publishing |date = 2006 |ISBN = 1-84176-997-5}} * {{cite book |last = Taylor |first = Michael J. H. |title = Jane's Encyclopedia of Aviation |publisher = Portland House |date = 1989 |ISBN = 0-517-69186-8}}

==External links== {{Commons category|Aviatik C.I}} *[https://www:greatwarpostcards.blogsplot.com July 14, 2011 1915 Wrecked Aviatik C.I postcard]

{{Aviatik aircraft}} {{World War I Aircraft of the Central Powers}} {{Idflieg C-class designations}} {{Authority control}}

[[Category:Aviatik aircraft|C.I]] [[Category:1910s German military reconnaissance aircraft]] [[Category:Single-engined tractor aircraft]] [[Category:Biplanes]] [[Category:Aircraft first flown in 1915]] [[Category:Aircraft with fixed conventional landing gear]]