View source for AGO C.IV

{{short description|German biplane reconnaissance aircraft}}
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{{Infobox aircraft
 |name= C.IV
 |image= AGO C.IV side.jpg
 |caption=
 |type= Reconnaissance
 |manufacturer= [[AGO Flugzeugwerke]]
 |designer=
 |first_flight=
 |introduction= 1917<ref name="Grey and Thetford p. 15">Grey and Thetford 1962, p. 15.</ref>
 |retired=
 |status=
 |primary_user= [[Luftstreitkräfte]]
 |more_users= [[Estonian Air Force]]
 |produced=
 |number_built= c. 70-100 (260 ordered)<ref name=Gray>{{cite book|last=Gray|first=Peter|title=German Aircraft of the First World War|url=https://archive.org/details/germanaircraftfi00thet|url-access=limited|year=1970|publisher=Putnam & Company Ltd.|location=London|isbn=0-370-00103-6|pages=[https://archive.org/details/germanaircraftfi00thet/page/n25 13]–16|edition=2nd|author2=Owen Thetford}}</ref>
 |variants=
}}

The '''AGO C.IV''' was a German [[biplane]] [[reconnaissance aircraft]] designed and produced by the German aircraft manufacturer [[AGO Flugzeugwerke]]. It was active with the [[Luftstreitkräfte]] during the latter half of the [[First World War]].

The C.IV was developed as a dedicated aerial reconnaissance platform and followed a generally conventional design for the era. However, it was equipped with sharply tapered wings that had a complex structure; additionally, it was initially designed without a vertical [[fin]], although one was promptly added when directional stability proved to be insufficient. The fuselage, while otherwise of an orthodox design, featured [[Composite material|composite]] construction. Some of these design choices are thought to have made the C.IV relatively complex to manufacture, which likely hindered the type's production rate considerably.

Within the opening weeks of 1917, the C.IV was operational with the Luftstreitkräfte. Although commonly recognised as being a relatively fast and well-armed aircraft for the era, the C.IV proved to be somewhat unstable during flight, and thus was typically disliked by pilots. Its limited availability also made its impact on the war negligible at best. Despite the efforts of three separate manufacturers to produce the type, less than 100 C.IVs were completed by the enactment of the [[Armistice of 11 November 1918]] that ended the conflict. In addition to the Luftstreitkräfte, it was also operated by the [[Estonian Air Force]] during the early [[Interwar period]].

==Development==
During 1916, the German aircraft manufacturer [[AGO Flugzeugwerke]] commenced work on a new combat aircraft for the [[Luftstreitkräfte]].<ref name="Grey and Thetford p. 13"/> It was intended to be a high performance aircraft for the era, specifically to be used in the [[aerial reconnaissance]] role, yet provide a good field of defensive fire. The general configuration of the aircraft represented a departure from the manufacturer's preference for the pod-and-boom configuration. The C.IV's original design lacked a fixed vertical [[fin]] and had a [[comma]]-shaped [[rudder]]; this arrangement was revised for production, bolstering directional stability by adding a vertical fin and substantially easing the strain imposed on its pilots.<ref name="Grey and Thetford p. 13"/> The tail unit would also see considerable revision, the original cable bracing arrangement being substituted for a rigid diagonal strut supported by streamlined steel tubing.<ref name="Grey and Thetford p. 13">Grey and Thetford 1962, p. 13.</ref> As designed, the C.IV only included a single pair of [[aileron]]s on the upper wing, yet many production aircraft would feature an additional pair on the lower wing as well.<ref name="Grey and Thetford p. 14"/>

While the design generally conformed with common conventions amongst military aircraft of the era, the C.IV was equipped with somewhat unusual wings, being sharply tapered from the center section of the wing.<ref name="Grey and Thetford p. 13"/> The main box spars supporting the wings were also atypically converged from root to tip. The I-section [[rib]]s were composed of [[Populus|poplar]] and fretted with lightening holes; the ribs of each panel were of a different size as well as being spaced at varying distances.<ref name="Grey and Thetford pp. 1314">Grey and Thetford 1962, pp. 13-14.</ref> The inner front interplane strut was deliberately omitted in order to improve the observer's forward field of fire. According to the aviation historians Peter Grey and Owen Thetford, the wings posed considerable manufacturing difficulty due to their complex design, and was a major factor in the limited production run for the type.<ref name="Grey and Thetford p. 14">Grey and Thetford 1962, p. 14.</ref>

The C.IV had a largely conventional fuselage structure, although some use of [[Composite material|composite]] construction was made in the form of wooden [[longeron]]s, steel tube spacers, and internal wire bracing (aft of the cockpit only) to form a relatively strong box girder structure.<ref name="Grey and Thetford p. 14"/> The top decking was completely detachable to facilitate servicing and repairs. While metal paneling enclosed the nose, engine, and forward-firing [[machine gun]], the majority of the fuselage was covered in [[plywood]] while the wings had a [[fabric]] covering instead.<ref name="Grey and Thetford pp. 1314"/> The undercarriage was supported by streamlined steel tubes and featured a claw-like brake arrangement. Fuel was housed in a main tank directly beneath the pilot; the piping to the engine cleanly ran through the center-section struts.<ref name="Grey and Thetford pp. 1415">Grey and Thetford 1962, pp. 14-15.</ref> Both the pilot and observer were provided with machine guns for self-defense purposes.<ref name="Grey and Thetford p. 16"/>

The C.IV was active in small numbers in the opening weeks of 1917.<ref name="Grey and Thetford p. 15"/> Pilots of these early examples often disliked them, commonly noting their instability during flight. It was believed that roughly 70 aircraft in total saw action with the Luftstreitkräfte; despite a considerably larger number having been ordered both from AGO and two other aircraft manufacturers who were to build the type [[licensed production|under licence]].<ref name="Grey and Thetford p. 15"/>

==Operators==
;{{EST}}
* [[Estonian Air Force]]<ref>Gerdessen 1982, p. 76.</ref>
;{{flag|German Empire}}
* [[Luftstreitkräfte]]

==Specifications==
[[File:AGO C.IV on trestle.jpg|thumb|Late production AGO C.IV on trestle]]
{{Aircraft specs
|ref= ''German Aircraft of the First World War''<ref name="Grey and Thetford p. 16">Grey and Thetford 1962, p. 16.</ref> 
|prime units?= met
<!--
        General characteristics
-->
|genhide=

|crew= 2
|capacity=
|length m= 8.25
|length ft=
|length in=
|length note=
|span m= 11.9
|span ft=
|span in=
|span note=
|upper span m=
|upper span ft=
|upper span in=
|upper span note=
|mid span m=
|mid span ft=
|mid span in=
|mid span note=
|lower span m=
|lower span ft=
|lower span in=
|lower span note=
|swept m=<!-- swing-wings -->
|swept ft=<!-- swing-wings -->
|swept in=<!-- swing-wings -->
|swept note=
|dia m=<!-- airships etc -->
|dia ft=<!-- airships etc -->
|dia in=<!-- airships etc -->
|dia note=
|width m=<!-- if applicable -->
|width ft=<!-- if applicable -->
|width in=<!-- if applicable -->
|width note=
|height m= 3.5
|height ft=
|height in=
|height note=
|wing area sqm= 37.5
|wing area sqft=
|wing area note=
|swept area sqm=<!-- swing-wings -->
|swept area sqft=<!-- swing-wings -->
|swept area note=
|volume m3=<!-- lighter-than-air -->
|volume ft3=<!-- lighter-than-air -->
|volume note=
|aspect ratio=<!-- sailplanes -->
|airfoil=
|empty weight kg= 900
|empty weight lb=
|empty weight note=
|gross weight kg= 1,350
|gross weight lb=
|gross weight note=
|max takeoff weight kg=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|lift kg=<!-- lighter-than-air -->
|lift lb=<!-- lighter-than-air -->
|lift note=
|more general=
<!--
        Powerplant
-->
|eng1 number= 1
|eng1 name= [[Benz Bz.IV]]
|eng1 type= six-cylinder water-cooled in-line piston engine
|eng1 kw=<!-- prop engines -->
|eng1 hp= 220
|eng1 shp=<!-- prop engines -->
|eng1 kn=<!-- jet/rocket engines -->
|eng1 lbf=<!-- jet/rocket engines -->
|eng1 note=
|power original=
|thrust original=
|eng1 kn-ab=<!-- afterburners -->
|eng1 lbf-ab=<!-- afterburners -->

|eng2 number=
|eng2 name=
|eng2 type=
|eng2 kw=<!-- prop engines -->
|eng2 hp=<!-- prop engines -->
|eng2 shp=<!-- prop engines -->
|eng2 kn=<!-- jet/rocket engines -->
|eng2 lbf=<!-- jet/rocket engines -->
|eng2 note=
|eng2 kn-ab=<!-- afterburners -->
|eng2 lbf-ab=<!-- afterburners -->

|eng3 number=
|eng3 name=
|eng3 type=
|eng3 kw=<!-- prop engines -->
|eng3 hp=<!-- prop engines -->
|eng3 shp=<!-- prop engines -->
|eng3 kn=<!-- jet/rocket engines -->
|eng3 lbf=<!-- jet/rocket engines -->
|eng3 note=
|eng3 kn-ab=<!-- afterburners -->
|eng3 lbf-ab=<!-- afterburners -->
|more power=

|prop blade number=<!-- propeller aircraft -->
|prop name=
|prop dia m=<!-- propeller aircraft -->
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=

|rot number=<!-- helicopters -->
|rot dia m=<!-- helicopters -->
|rot dia ft=<!-- helicopters -->
|rot dia in=<!-- helicopters -->
|rot area sqm=<!-- helicopters -->
|rot area sqft=<!-- helicopters -->
|rot area note=
<!--
        Performance
-->
|perfhide=

|max speed kmh= 190
|max speed mph=
|max speed kts=
|max speed note=
|max speed mach=<!-- supersonic aircraft -->
|cruise speed kmh=
|cruise speed mph=
|cruise speed kts=
|cruise speed note=
|stall speed kmh=
|stall speed mph=
|stall speed kts=
|stall speed note=
|never exceed speed kmh=
|never exceed speed mph=
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kmh=
|minimum control speed mph=
|minimum control speed kts=
|minimum control speed note=
|range km=
|range miles=
|range nmi=
|range note=
|combat range km=
|combat range miles=
|combat range nmi=
|combat range note=
|ferry range km=
|ferry range miles=
|ferry range nmi=
|ferry range note=
|endurance= Four hours
|ceiling m= 5,500
|ceiling ft=
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|glide ratio=<!-- sailplanes -->
|climb rate ms=
|climb rate ftmin=
|climb rate note=
|time to altitude= {{convert|3,000|m|ft|abbr=on|0}} in 22 minutes
|sink rate ms=<!-- sailplanes -->
|sink rate ftmin=<!-- sailplanes -->
|sink rate note=
|lift to drag=
|wing loading kg/m2=
|wing loading lb/sqft=
|wing loading note=
|disk loading kg/m2=
|disk loading lb/sqft=
|disk loading note=
|fuel consumption kg/km=
|fuel consumption lb/mi=
|power/mass=
|thrust/weight=

|more performance=
<!--
        Armament
-->
|guns=<br/>
** 1 x fixed forward firing [[MG 08]] "Spandau" machine gun fired by the pilot
** 1 x [[Parabellum MG 14]] machine gun aimed by the Observer.
|bombs= 
|rockets= 
|missiles= 
|hardpoints=
|hardpoint capacity=
|hardpoint rockets=
|hardpoint missiles=
|hardpoint bombs=
|hardpoint other=

|avionics=
}}

==References==
===Citations===
{{reflist}}

===Bibliography===
{{commons category}}
* {{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}}
* Gerdessen, Frederik. "Estonian Air Power 1918 – 1945". ''[[Air Enthusiast]]'', No. 18, April – July 1982. pp.&nbsp;61–76. {{ISSN|0143-5450}}.
* {{cite book |last = Taylor |first = Michael J. H. |title = Jane's Encyclopedia of Aviation |year = 1989 |publisher=Studio Editions |location=London |pages=40 }}
* [http://www.airwar.ru/enc/other1/agoc4.html Airwar.ru]

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

[[Category:AGO aircraft|C.IV]]
[[Category:1910s German military reconnaissance aircraft|AGO C.04]]
[[Category:Single-engined tractor aircraft]]
[[Category:Biplanes]]
[[Category:Aircraft first flown in 1916]]