Gotha WD.7: Difference between revisions
| (47 intermediate revisions by 3 users not shown) | |||
| Line 2: | Line 2: | ||
<!-- 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 Begin |
{|{{Infobox Aircraft Begin |
||
|name=WD.7 |
|name=WD.7 |
||
|image=Gotha WD.7 on beaching trolleys.jpg |
|image=Gotha WD.7 on beaching trolleys.jpg |
||
|caption=A forward oblique view of a WD.7 on its beaching trolleys |
|caption=A forward oblique view of a WD.7 on its beaching trolleys |
||
}}{{Infobox Aircraft Type |
}}{{Infobox Aircraft Type |
||
|type=torpedo-bomber trainer |
|type=[[Maritime reconnaissance aircraft]] and torpedo-bomber trainer |
||
|national origin=Germany |
|national origin=Germany |
||
|manufacturer=[[Gothaer Waggonfabrik |
|manufacturer={{lang|de|[[Gothaer Waggonfabrik]]}} |
||
|designer= |
|designer=[[Karl Rösner]] |
||
|first flight= |
|first flight= |
||
|introduced= |
|||
|retired= |
|||
|status= |
|||
|primary user=[[Imperial German Navy]] |
|primary user=[[Imperial German Navy]] |
||
|variants with their own articles=[[Gotha WD.8]] |
|||
|more users= |
|||
|produced= |
|produced= |
||
|number built= |
|number built=8 |
||
|variants with their own articles= |
|||
}} |
}} |
||
|} |
|} |
||
The '''Gotha WD.7''' ({{lang|de|Wasser Doppeldecker}} - "Water [[Biplane]]") was a twin-engine [[Maritime patrol aircraft|maritime patrol]] [[floatplane]] developed during [[World War I]] by {{lang|de|[[Gothaer Waggonfabrik]]}} (Gotha) for the [[Imperial German Navy]]'s ({{lang|de|Kaiserliche Marine}}) Naval Air Service ({{lang|de|Marine-Fliegerabteilung}}). The [[prototype]] was captured by the French on its first combat mission in April 1916 after it was forced to make an [[emergency landing]] after an engine failed. Despite this seven additional WD.7s were ordered and were used for training [[torpedo bomber]] pilots and for trials. Only a single aircraft is known to have survived the war. |
|||
The '''Gotha WD.7''' (''Wasser Doppeldecker'' - "Water [[Biplane]]") was a [[reconnaissance]] [[floatplane]] developed in the [[German Empire]] during [[World War I]]. |
|||
==Background and description== |
|||
==Development== |
|||
A decade after the [[Wright Brothers]] made the first [[heavier-than-air flight]] in 1903, obvious missions for aircraft were [[reconnaissance]] and [[ground attack]] and the consequent need to negate the enemy's attempts perform them against your own troops. Although [[synchronizer gear]] to allow [[machine gun]]s to fire between the [[propeller (aeronautics)|propeller]] blades as they spun was under development in multiple countries, a successful system had yet to be fielded. This meant that the machine gun placed on a rotating mount with a [[field of fire]] unimpeded the propellers was the only way that one aircraft could shoot down another. This relegated the pilot to merely flying withing range of an enemy aircraft while his [[air gunner|gunners]] would attempt to destroy their opponent with their machine guns and [[autocannon]]. Designers and military aviators likened this to warships at sea which maneuvered to bring their weapons to bear. Thus were born the aerial cruisers or battleplanes ({{lang|de|Kampfflugzeuge}}) built by Imperial Germany, Great Britain and France.<ref>Herris, p. 97</ref> |
|||
After the [[submarine]] {{SMU|U-9}} sank three British [[armored cruiser]]s on 22 September 1914 shortly after the war began, the [[German Imperial Naval Office]] ({{lang|de|Reichsmarine-Amt}}) decided to try mounting [[torpedo]]es on aircraft as they were far easier and faster to build than submarines. Early trials with land-based aircraft were unsuccessful because of the great weight of the torpedo ({{convert|645|kg|sp=us}}) was more than existing aircraft could easily lift and the danger of trying to fly from an uneven grass [[airstrip]] with such a large weight of explosives. At the beginning of 1915 the Naval Office ordered the development of [[seaplane]]s capable of carrying torpedoes and the Seaplane Experimental Command ({{lang|de|Seeflugzeug-Versuchs-Kommando}} (SVK)) issued requirements for these aircraft. They had to be twin-engine airplanes armed with a [[machine gun]] for self-defense and with a crew of two or three men: a pilot and observer for torpedo missions and a pilot, [[bombardier (aircrew)|bombardier]] and gunner for bombing missions.<ref>Schmeelke, pp. 3, 10, 21</ref> |
|||
At the beginning of 1914, the [[Imperial German Army]]'s [[Imperial German Air Service]] ({{lang|de|Die Fliegertruppen des deutschen Kaiserreiches}}) began discussions with its [[Idflieg|Inspectorate of Flying Troops]] ({{lang|de|Inspektion der Fliegertruppen}} ({{lang|de|Idflieg}})), the Transport Technical Investigation Commission ({{lang|de|Verkehrstechnische Prüfungs Kommission}} (VPK)) and aviation industry executives about the wartime role of aircraft. In March they reached a consensus outlining three broad roles for aircraft: |
|||
[[File:Gotha WD.8.jpg|thumb|Gotha WD.8]] |
|||
* Type I; a fast two-seater [[Reconnaissance aircraft|reconnaissance]] or [[bomber aircraft]]. |
|||
After the pusher [[Gotha WD.3|WD.3]] was not accepted by the Imperial German Navy, [[Gothaer Waggonfabrik|Gotha]] turned to a new layout that would keep the aircraft's nose free for forward-firing weapons. The WD.7 therefore, was a conventional biplane with twin engines mounted tractor-fashion on the leading edge of the lower wing. Eight examples were built for use as trainers for [[torpedo]] bombing. During 1917, two of these aircraft were used for testing a 37 mm (1.46 in) autocannon built by [[Deutsche Waffen und Munitionsfabriken|DWM]]. |
|||
* Type II; a short-range, two-seat, very maneuverable aircraft intended to fly at low altitudes and armed for self-defense. |
|||
* Type III; a long-range aircraft able to carry {{convert|450|kg}} of useful load for six hours withing range of enemy fire. |
|||
The Central Division ({{lang|de|Zentral-Abteilung}}) of the [[German General Staff|General Staff]] approved the VPK's recommendations on 28 April, directing that aircraft be developed for the Type II and III categories as quickly as possible as the Type I requirement was already met by the existing [[Idflieg aircraft designation system|B-type]] aircraft. The Air Service scheduled a competition to select the best Type II aircraft in November and another in early 1915 for the Type III aircraft as those larger and more complex aircraft would require more time to design and build, not least because two engines would be required as Germany lacked engines powerful enough to lift that weight on their own. The start of World War I in August disrupted these plans, although many companies had already made considerable progress with their Type III designs. Rather than hold a competition, {{lang|de|Idflieg}} decided to order small numbers of prototypes from the various manufacturers.<ref>Grosz, pp. 1–2</ref> |
|||
The Naval Air Service decided that it wanted floatplane equivalents of the {{lang|de|Kampfflugzeuge}} and ordered one prototype from Gotha on 10 May 1915. Designed by [[Karl Rösner]], the WD.7 was a [[tractor configuration|tractor-configuration]] [[Biplane#Bays|two-bay biplane]] with {{convert|120|hp|adj=on|lk=on}} [[Mercedes D.II]] [[straight-six engine]]s mounted on the [[leading edge]] of the lower wing. The [[Radiator (engine cooling)|radiators]] were located above each engine. The aircraft retained the design of the WD.3's nose gunner's position, but it had an entirely new [[fuselage]] with the pilot's [[cockpit]] behind the gunner's position. It also used the same style of [[Twin tail|twin-tail]] [[empennage|structure]]. The prototype kept the central [[vertical stabilizer]] as well, but this was eliminated in the production aircraft. Its [[Float (nautical)|floats]] were attached to the lower wing via [[Bracing (aeronautics)|struts]] directly below the engines. A pair of lateral struts reinforced the floats, but also precluded the aircraft from carrying bombs or torpedoes underneath the fuselage. The gunner was armed with a {{cvt|7.92|mm}} [[Parabellum MG 14]] machine gun on a ring mount.<ref>Nowarra, Robertson & Cooksley, p. 44</ref><ref>Herris, p. 36</ref><ref>Metzmacher, p. 63</ref> |
|||
The same airframe was used to create the '''WD.8''' reconnaissance floatplane, substituting the twin wing-mounted engines with a single [[Maybach Mb.IVa]] in the nose. |
|||
==History== |
|||
<!-- ==Operational history== --> |
|||
The prototype was delivered to Naval Air Station Flanders I ({{lang|de|Seeflugstation Flandern I}}) at [[Zeebrugge]] in [[German occupation of Belgium during World War I|Occupied Belgium]] on 8 February 1916, but inclement weather prevented operational missions for several months. The aircraft was tasked with the morning reconnaissance mission off the Belgian and French coastlines on 2 April, but one engine broke down over [[Calais]], France, and the pilot was able to make an emergency landing north of the port. He attempted to [[taxiing|taxi]] back to [[Ostend]], Belgium, but the WD.7 caught fire and was captured by a French [[destroyer]] south of [[Dunkirk]], France.<ref>Schmeelke 2018, p. 70, 85–87</ref> |
|||
Seven additional WD.7s were ordered on 24 February; the first six of them used {{cvt|100|hp}} [[Mercedes D.I]] engines, but the last aircraft was fitted with 120 hp [[Argus As II|Argus As.II]] engines. Delivered in June–August,<ref>Herris, pp. 45, 95</ref> most were used to train torpedo bomber pilots at the [[seaplane]] bases in [[Warnemünde]], [[Apenrade]], [[Norderney]] and [[Flensburg]]. Several aircraft were retained by the Seaplane Experimental Command ({{lang|de|Seeflugzeug-Versuchs-Kommando}}) for testing, including temporarily fitting a WD.7 with [[Austria-Hungary|Austro-Hungarian]] {{cvt|130|hp}} Hiero engines. One aircraft is known to have been used for trials of the [[Becker Type M2 20 mm cannon|Becker {{cvt|20|mm|1}}]] autocannon beginning in late 1916. A 37 mm (1.5 in) autocannon built by [[Deutsche Waffen und Munitionsfabriken|DWM]] was also tested aboard these aircraft.<ref>Herris, p. 45; Metzmacher, p. 64</ref><ref>Schmeelke 2020, p. 15</ref> When the [[Allies of World War I|Allies]] inspected the German seaplane bases in December 1918, they recorded a single surviving WD.7 at [[Hage]]. Its ultimate fate is unknown, but it was likely [[scrapped]].<ref>Andersson & Sanger, p. 18</ref> |
|||
The Naval Air Service wanted to conduct comparative trials between single- and twin-engined versions of the same [[airframe]] with the same total power. It ordered the WD.8 reconnaissance floatplane prototype in July 1915 that substituted a single {{convert|240|hp|adj=on}} [[Maybach Mb.IVa]] engine in the nose. It was not successful and the prototype was later sold to the [[Ottoman Empire]].<ref>Herris, p. 48</ref> |
|||
==Variants== |
==Variants== |
||
'''WD.8''': one prototype of a single-engine version, powered by a Maybach Mb.IV.<ref name=Gray/> |
|||
;WD.8:single-engine reconnaissance floatplane, powered by a {{cvt|240|hp}} [[Maybach Mb.IV]].<ref name=Gray/> |
|||
<!-- ==Units using this aircraft/Operators (choose)== --> |
|||
==Specifications (WD.7)== |
==Specifications (WD.7 prototype)== |
||
[[File:Gotha_WD.7_3-view_Aviation_and_Aeronautical_Engineering_September_15,1916.png|alt=|thumb|Gotha WD.7 3-view drawing from ''Aviation and Aeronautical Engineering'' September 15, 1916]] |
[[File:Gotha_WD.7_3-view_Aviation_and_Aeronautical_Engineering_September_15,1916.png|alt=|thumb|Gotha WD.7 3-view drawing from ''Aviation and Aeronautical Engineering'' September 15, 1916]] |
||
{{Aircraft specs |
{{Aircraft specs |
||
|ref=German Aircraft of the First World War<ref name=Gray>Gray & Thetford, p. 400</ref> |
|ref=Gotha Aircraft of WWI: A Centennial Perspective on Great War Airplanes;<ref>Herris, p. 45</ref> German Aircraft of the First World War<ref name=Gray>Gray & Thetford, p. 400</ref> |
||
|prime units?=met |
|prime units?=met |
||
<!-- |
<!-- |
||
| Line 48: | Line 50: | ||
|genhide= |
|genhide= |
||
|crew= |
|crew=2 |
||
|capacity= |
|capacity= |
||
|length m=11.3 |
|length m=11.3 |
||
|length ft= |
|length ft= |
||
|length in= |
|length in= |
||
|length note= |
|length note= |
||
|span m= |
|||
::::'''WD.8:''' {{cvt|11.2|m}} |
|||
|span m=16 |
|||
|span ft= |
|span ft= |
||
|span in= |
|span in= |
||
|span note= |
|span note= |
||
|upper span m= |
|upper span m=16.8 |
||
|upper span ft= |
|upper span ft= |
||
|upper span in= |
|upper span in= |
||
|upper span note= |
|upper span note= |
||
| |
|lower span m=14.8 |
||
|mid span ft= |
|||
|mid span in= |
|||
|mid span note= |
|||
|lower span m= |
|||
|lower span ft= |
|lower span ft= |
||
|lower span in= |
|lower span in= |
||
|lower span note= |
|lower span note= |
||
|height m=3.9 |
|||
|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=3.585 |
|||
|height ft= |
|height ft= |
||
|height in= |
|height in= |
||
| Line 89: | Line 74: | ||
|wing area sqm=55.5 |
|wing area sqm=55.5 |
||
|wing area sqft= |
|wing area sqft= |
||
|wing area note= |
|wing area note= |
||
::::'''WD.8:''' {{cvt|59|m2}} |
|||
|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= |
|airfoil= |
||
|empty weight kg= |
|empty weight kg=1275 |
||
|empty weight lb= |
|empty weight lb= |
||
|empty weight note= |
|empty weight note= |
||
|gross weight kg=1785 |
|||
::::'''WD.8:''' {{cvt|1250|kg}} |
|||
|gross weight kg=1970 |
|||
|gross weight lb= |
|gross weight lb= |
||
|gross weight note= |
|gross weight note= |
||
::::'''WD.8:''' {{cvt|1770|kg}} |
|||
|max takeoff weight kg= |
|max takeoff weight kg= |
||
|max takeoff weight lb= |
|max takeoff weight lb= |
||
|max takeoff weight note= |
|max takeoff weight note= |
||
|fuel capacity= |
|fuel capacity= |
||
|lift kg=<!-- lighter-than-air --> |
|||
|lift lb=<!-- lighter-than-air --> |
|||
|lift note= |
|||
|more general= |
|more general= |
||
<!-- |
<!-- |
||
| Line 120: | Line 92: | ||
|eng1 number=2 |
|eng1 number=2 |
||
|eng1 name=[[Mercedes D.II]] |
|eng1 name=[[Mercedes D.II]] |
||
|eng1 type= |
|eng1 type=[[water-cooled]] [[straight-six engine]]s |
||
|eng1 hp=120 |
|eng1 hp=120 |
||
|prop blade number= |
|prop blade number=2 |
||
|prop name= |
|prop name= |
||
|prop dia m=<!-- propeller aircraft --> |
|prop dia m=<!-- propeller aircraft --> |
||
| Line 130: | Line 102: | ||
|prop dia note= |
|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 |
Performance |
||
| Line 142: | Line 107: | ||
|perfhide= |
|perfhide= |
||
|max speed kmh= |
|max speed kmh=128 |
||
|max speed mph= |
|max speed mph= |
||
|max speed kts= |
|max speed kts= |
||
|max speed note= |
|max speed note= |
||
|range km=475 |
|||
::::'''WD.8:''' {{cvt|130|km/h|mph kn}} |
|||
|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 miles= |
||
|range nmi= |
|range nmi= |
||
| Line 177: | Line 124: | ||
|ferry range note= |
|ferry range note= |
||
|endurance=<!-- if range unknown --> |
|endurance=<!-- if range unknown --> |
||
|ceiling m= |
|ceiling m=3500 |
||
|ceiling ft= |
|ceiling ft= |
||
|ceiling note= |
|ceiling note= |
||
::::'''WD.8:''' {{cvt|4500|m}} |
|||
|g limits=<!-- aerobatic --> |
|||
|roll rate=<!-- aerobatic --> |
|||
|glide ratio=<!-- sailplanes --> |
|||
|climb rate ms= |
|climb rate ms= |
||
|climb rate ftmin= |
|climb rate ftmin= |
||
|climb rate note= |
|climb rate note= |
||
|time to altitude= |
|time to altitude=9.5 minutes to {{cvt|1000|m}} |
||
:::::*40 minutes to {{cvt|2000|m}} |
|||
|sink rate ms=<!-- sailplanes --> |
|||
|sink rate ftmin=<!-- sailplanes --> |
|||
|sink rate note= |
|||
|lift to drag= |
|lift to drag= |
||
|wing loading kg/m2= |
|wing loading kg/m2= |
||
| Line 207: | Line 148: | ||
Armament |
Armament |
||
--> |
--> |
||
|guns= |
|guns= 1 x flexible {{cvt|7.92|mm|3}} [[Parabellum MG 14]] |
||
|bombs= |
|||
|bombs='''WD.7:''' 1 x training torpedo |
|||
}} |
}} |
||
| Line 215: | Line 156: | ||
==Bibliography== |
==Bibliography== |
||
{{Commons category multi|Gotha WD.7 |
{{Commons category multi|Gotha WD.7}} |
||
*{{cite book |last1=Andersson |first1=Lennart |last2=Sanger |first2=Ray |title=Retribution and Recovery: German Aircraft and Aviation 1919 to 1922 |date=2014 |publisher=Air-Britain (Historians) |location=Staplefield, UK |isbn=978-0-85130-467-0|name-list-style=amp}} |
|||
* {{cite book|author1-last=Gray|author1-first=Peter|title=German Aircraft of the First World War|orig-year=1970|year=1987 |publisher=Putnam |location=London|isbn=0-85177-809-7|edition=2nd|author2-first=Owen|author2-last=Thetford|name-list-style=amp}} |
* {{cite book|author1-last=Gray|author1-first=Peter|title=German Aircraft of the First World War|orig-year=1970|year=1987 |publisher=Putnam |location=London|isbn=0-85177-809-7|edition=2nd|author2-first=Owen|author2-last=Thetford|name-list-style=amp}} |
||
* {{cite book |last=Grosz |first=Peter M. |year=2000 |series=Windsock Datafile |title=Gotha G.I |publisher=Albatros Productions |location=Berkhamsted, UK |isbn=1-902207-25-4|volume=83}} |
|||
*{{cite book |last1=Herris |first1=Jack |title=Gotha Aircraft of WWI: A Centennial Perspective on Great War Airplanes |date=2013 |publisher=Aeronaut Books |location=Charleston, South Carolina |isbn=978-1-935881-14-8|series=Great War Aviation Centennial Series|volume=6}} |
*{{cite book |last1=Herris |first1=Jack |title=Gotha Aircraft of WWI: A Centennial Perspective on Great War Airplanes |date=2013 |publisher=Aeronaut Books |location=Charleston, South Carolina |isbn=978-1-935881-14-8|series=Great War Aviation Centennial Series|volume=6}} |
||
*{{cite book |last1=Metzmacher |first1=Andreas |title=Gotha Aircraft 1913–1954: From the London Bomber to the Flying Wing Jet Fighter |date=2021 |publisher=Fonthill |location=Brimscombe, Stroud |isbn=978-1-78155-706-8}} |
*{{cite book |last1=Metzmacher |first1=Andreas |title=Gotha Aircraft 1913–1954: From the London Bomber to the Flying Wing Jet Fighter |date=2021 |publisher=Fonthill |location=Brimscombe, Stroud |isbn=978-1-78155-706-8}} |
||
* {{cite book |last1= Nowarra |first1=Heinz J.|last2=Robertson|first2=Bruce|last3=Cooksley|first3=Peter G. |title=Marine Aircraft of the 1914–1918 War |publisher=Harleyford Publications |location=Letchworth, UK|name-list-style=amp |year=1966|oclc=123198808}} |
|||
*{{cite book|last1=Schmeelke |first1=Michael |title="Torpedo Los!": The German Imperial Torpedo-Flieger |date=2020 |publisher=Aeronaut Books |location=n.p. |isbn=978-1-953201-17-1}} |
*{{cite book|last1=Schmeelke |first1=Michael |title="Torpedo Los!": The German Imperial Torpedo-Flieger |date=2020 |publisher=Aeronaut Books |location=n.p. |isbn=978-1-953201-17-1}} |
||
* {{cite book |last1=Schmeelke |first1=Michael |title=Zeebrugge: Naval Air Station Flanders I 1914–1918 |date=2018 |publisher=Aeronaut Books |location=Reno, Nevada |isbn=978-1-935881-46-9 | ref=none}} |
* {{cite book |last1=Schmeelke |first1=Michael |title=Zeebrugge: Naval Air Station Flanders I 1914–1918 |date=2018 |publisher=Aeronaut Books |location=Reno, Nevada |isbn=978-1-935881-46-9 | ref=none}} |
||
Revision as of 11:18, 4 May 2024
| WD.7 | |
|---|---|
| |
| A forward oblique view of a WD.7 on its beaching trolleys | |
| Role | Maritime reconnaissance aircraft and torpedo-bomber trainer |
| National origin | Germany |
| Manufacturer | Gothaer Waggonfabrik |
| Designer | Karl Rösner |
| Primary user | Imperial German Navy |
| Number built | 8 |
| Variants | Gotha WD.8 |
The Gotha WD.7 (Wasser Doppeldecker - "Water Biplane") was a twin-engine maritime patrol floatplane developed during World War I by Gothaer Waggonfabrik (Gotha) for the Imperial German Navy's (Kaiserliche Marine) Naval Air Service (Marine-Fliegerabteilung). The prototype was captured by the French on its first combat mission in April 1916 after it was forced to make an emergency landing after an engine failed. Despite this seven additional WD.7s were ordered and were used for training torpedo bomber pilots and for trials. Only a single aircraft is known to have survived the war.
Background and description
A decade after the Wright Brothers made the first heavier-than-air flight in 1903, obvious missions for aircraft were reconnaissance and ground attack and the consequent need to negate the enemy's attempts perform them against your own troops. Although synchronizer gear to allow machine guns to fire between the propeller blades as they spun was under development in multiple countries, a successful system had yet to be fielded. This meant that the machine gun placed on a rotating mount with a field of fire unimpeded the propellers was the only way that one aircraft could shoot down another. This relegated the pilot to merely flying withing range of an enemy aircraft while his gunners would attempt to destroy their opponent with their machine guns and autocannon. Designers and military aviators likened this to warships at sea which maneuvered to bring their weapons to bear. Thus were born the aerial cruisers or battleplanes (Kampfflugzeuge) built by Imperial Germany, Great Britain and France.[1]
At the beginning of 1914, the Imperial German Army's Imperial German Air Service (Die Fliegertruppen des deutschen Kaiserreiches) began discussions with its Inspectorate of Flying Troops (Inspektion der Fliegertruppen (Idflieg)), the Transport Technical Investigation Commission (Verkehrstechnische Prüfungs Kommission (VPK)) and aviation industry executives about the wartime role of aircraft. In March they reached a consensus outlining three broad roles for aircraft:
- Type I; a fast two-seater reconnaissance or bomber aircraft.
- Type II; a short-range, two-seat, very maneuverable aircraft intended to fly at low altitudes and armed for self-defense.
- Type III; a long-range aircraft able to carry 450 kilograms (990 lb) of useful load for six hours withing range of enemy fire.
The Central Division (Zentral-Abteilung) of the General Staff approved the VPK's recommendations on 28 April, directing that aircraft be developed for the Type II and III categories as quickly as possible as the Type I requirement was already met by the existing B-type aircraft. The Air Service scheduled a competition to select the best Type II aircraft in November and another in early 1915 for the Type III aircraft as those larger and more complex aircraft would require more time to design and build, not least because two engines would be required as Germany lacked engines powerful enough to lift that weight on their own. The start of World War I in August disrupted these plans, although many companies had already made considerable progress with their Type III designs. Rather than hold a competition, Idflieg decided to order small numbers of prototypes from the various manufacturers.[2]
The Naval Air Service decided that it wanted floatplane equivalents of the Kampfflugzeuge and ordered one prototype from Gotha on 10 May 1915. Designed by Karl Rösner, the WD.7 was a tractor-configuration two-bay biplane with 120-horsepower (89 kW) Mercedes D.II straight-six engines mounted on the leading edge of the lower wing. The radiators were located above each engine. The aircraft retained the design of the WD.3's nose gunner's position, but it had an entirely new fuselage with the pilot's cockpit behind the gunner's position. It also used the same style of twin-tail structure. The prototype kept the central vertical stabilizer as well, but this was eliminated in the production aircraft. Its floats were attached to the lower wing via struts directly below the engines. A pair of lateral struts reinforced the floats, but also precluded the aircraft from carrying bombs or torpedoes underneath the fuselage. The gunner was armed with a 7.92 mm (0.312 in) Parabellum MG 14 machine gun on a ring mount.[3][4][5]
History
The prototype was delivered to Naval Air Station Flanders I (Seeflugstation Flandern I) at Zeebrugge in Occupied Belgium on 8 February 1916, but inclement weather prevented operational missions for several months. The aircraft was tasked with the morning reconnaissance mission off the Belgian and French coastlines on 2 April, but one engine broke down over Calais, France, and the pilot was able to make an emergency landing north of the port. He attempted to taxi back to Ostend, Belgium, but the WD.7 caught fire and was captured by a French destroyer south of Dunkirk, France.[6]
Seven additional WD.7s were ordered on 24 February; the first six of them used 100 hp (75 kW) Mercedes D.I engines, but the last aircraft was fitted with 120 hp Argus As.II engines. Delivered in June–August,[7] most were used to train torpedo bomber pilots at the seaplane bases in Warnemünde, Apenrade, Norderney and Flensburg. Several aircraft were retained by the Seaplane Experimental Command (Seeflugzeug-Versuchs-Kommando) for testing, including temporarily fitting a WD.7 with Austro-Hungarian 130 hp (97 kW) Hiero engines. One aircraft is known to have been used for trials of the Becker 20 mm (0.8 in) autocannon beginning in late 1916. A 37 mm (1.5 in) autocannon built by DWM was also tested aboard these aircraft.[8][9] When the Allies inspected the German seaplane bases in December 1918, they recorded a single surviving WD.7 at Hage. Its ultimate fate is unknown, but it was likely scrapped.[10]
The Naval Air Service wanted to conduct comparative trials between single- and twin-engined versions of the same airframe with the same total power. It ordered the WD.8 reconnaissance floatplane prototype in July 1915 that substituted a single 240-horsepower (180 kW) Maybach Mb.IVa engine in the nose. It was not successful and the prototype was later sold to the Ottoman Empire.[11]
Variants
WD.8: one prototype of a single-engine version, powered by a Maybach Mb.IV.[12]
Specifications (WD.7 prototype)
Data from Gotha Aircraft of WWI: A Centennial Perspective on Great War Airplanes;[13] German Aircraft of the First World War[12]
General characteristics
- Crew: 2
- Length: 11.3 m (37 ft 1 in)
- Upper wingspan: 16.8 m (55 ft 1 in)
- Lower wingspan: 14.8 m (48 ft 7 in)
- Height: 3.9 m (12 ft 10 in)
- Wing area: 55.5 m2 (597 sq ft)
- Empty weight: 1,275 kg (2,811 lb)
- Gross weight: 1,785 kg (3,935 lb)
- Powerplant: 2 × Mercedes D.II water-cooled straight-six engines, 89 kW (120 hp) each
- Propellers: 2-bladed
Performance
- Maximum speed: 128 km/h (80 mph, 69 kn)
- Range: 475 km (295 mi, 256 nmi)
- Service ceiling: 3,500 m (11,500 ft)
- Time to altitude: 9.5 minutes to 1,000 m (3,300 ft)
- 40 minutes to 2,000 m (6,600 ft)
Armament
- Guns: 1 x flexible 7.92 mm (0.312 in) Parabellum MG 14
References
- ^ Herris, p. 97
- ^ Grosz, pp. 1–2
- ^ Nowarra, Robertson & Cooksley, p. 44
- ^ Herris, p. 36
- ^ Metzmacher, p. 63
- ^ Schmeelke 2018, p. 70, 85–87
- ^ Herris, pp. 45, 95
- ^ Herris, p. 45; Metzmacher, p. 64
- ^ Schmeelke 2020, p. 15
- ^ Andersson & Sanger, p. 18
- ^ Herris, p. 48
- ^ a b Gray & Thetford, p. 400
- ^ Herris, p. 45
Bibliography
- Andersson, Lennart & Sanger, Ray (2014). Retribution and Recovery: German Aircraft and Aviation 1919 to 1922. Staplefield, UK: Air-Britain (Historians). ISBN 978-0-85130-467-0.
- Gray, Peter & Thetford, Owen (1987) [1970]. German Aircraft of the First World War (2nd ed.). London: Putnam. ISBN 0-85177-809-7.
- Grosz, Peter M. (2000). Gotha G.I. Windsock Datafile. Vol. 83. Berkhamsted, UK: Albatros Productions. ISBN 1-902207-25-4.
- Herris, Jack (2013). Gotha Aircraft of WWI: A Centennial Perspective on Great War Airplanes. Great War Aviation Centennial Series. Vol. 6. Charleston, South Carolina: Aeronaut Books. ISBN 978-1-935881-14-8.
- Metzmacher, Andreas (2021). Gotha Aircraft 1913–1954: From the London Bomber to the Flying Wing Jet Fighter. Brimscombe, Stroud: Fonthill. ISBN 978-1-78155-706-8.
- Nowarra, Heinz J.; Robertson, Bruce & Cooksley, Peter G. (1966). Marine Aircraft of the 1914–1918 War. Letchworth, UK: Harleyford Publications. OCLC 123198808.
- Schmeelke, Michael (2020). "Torpedo Los!": The German Imperial Torpedo-Flieger. n.p.: Aeronaut Books. ISBN 978-1-953201-17-1.
- Schmeelke, Michael (2018). Zeebrugge: Naval Air Station Flanders I 1914–1918. Reno, Nevada: Aeronaut Books. ISBN 978-1-935881-46-9.