View source for Engineering:Oerlikon GDF


{{Infobox weapon
| name               = Oerlikon GDF
| image              = File:Swiss Oerlikon GDF 35 mm Anti-aircraft Gun with Skyguard Fire Control System 1979.jpg
| image_size         = 300
| caption            = A modernized Finnish 35 mm Oerlikon twin cannon
| origin             = Switzerland
| type               = [[Engineering:Autocannon|Autocannon]]
<!-- Type selection -->| is_ranged          = YES
| is_bladed          = 
| is_explosive       = 
| is_artillery       = YES
| is_vehicle         = <!-- Service history -->
| service            = 1963–Present<ref name="WEAPONSYSTEMS.NET">{{cite web |title=Oerlikon GDF |url=https://weaponsystems.net/system/933-Oerlikon+GDF |website=WeaponSystems.net |access-date=5 July 2021}}</ref>
| used_by            = See ''Operators''
| wars               = Iran-Iraq War<br/>Falklands War
<!-- Production history -->| designer           = Oerlikon
| design_date        = 
| manufacturer       = Oerlikon
| production_date    = 
| number             = 
| variants           = <!-- General specifications -->
| weight             = {{convert|6700|kg|abbr=on|lk=on}} (with ammunition)
| length             = {{convert|7.8|m|ftin|abbr=on}} (travelling)
| part_length        = {{convert|3.15|m|ftin|abbr=on}} (barrel)
| width              = {{convert|2.26|m|ftin|abbr=on}} (travelling)
| height             = {{convert|2.6|m|ftin|abbr=on}} (travelling)
| crew               = 3<ref>{{Cite book|title=Jane's pocket book of towed artillery|last=Foss|first=Christopher|date=1977|publisher=Collier|page=227|isbn=0020806000|location=New York|oclc=911907988}}</ref>
<!-- Ranged weapon specifications -->| cartridge          = Complete round: 35×228mm, {{convert|1.565|kg|lboz|abbr=on|sigfig=1}}
| caliber            = {{convert|35|mm|in|abbr=on}}
| action             = Gas-operated<ref name=oerlikon35>{{cite book |title=The Naval Institute Guide to World Naval Weapons Systems, 1997–1998 |chapter=Oerlikon 35mm (Type GDM-A and GDM-C) |last=Friedman |first=Norman |year=1997–1998 |publisher=Naval Institute Press |location=Annapolis, Md. |isbn=978-1-55750-268-1 |page=455 |chapter-url=https://books.google.com/books?id=l-DzknmTgDUC&pg=PA431 |access-date=April 6, 2012}}</ref>
| rate               = 550 rounds/min (per barrel)
| velocity           = {{convert|1175|m/s|abbr=on}} (HEI-T)
| range              = Ceiling: {{convert|4000|m|ft|abbr=on}}
| max_range          = 
| feed               = 
| sights             = <!-- Artillery specifications -->
| breech             = 
| recoil             = 
| carriage           = 4 wheels with [[Engineering:Gun carriage#Modern gun carriages|outrigger]]s
| elevation          = −5°/+92°
| traverse           = Full 360°
<!-- Bladed weapon specifications -->| blade_type         = 
| hilt_type          = 
| head_type          = 
| haft_type          = <!-- Explosive specifications -->
| diameter           = 
| filling            = 
| filling_weight     = 
| detonation         = 
| yield              = 
}}

The '''Oerlikon GDF'''<ref name=":0">{{cite web|url=http://weaponsystems.net/weapon.php?weapon=EE02+-+GDF|title=GDF - Weaponsystems.net|website=weaponsystems.net|access-date=2017-07-03|archive-url=https://web.archive.org/web/20160308120224/http://weaponsystems.net/weapon.php?weapon=ee02+-+gdf|archive-date=2016-03-08|url-status=live}}</ref> or '''Oerlikon 35&nbsp;mm twin cannon''' is a towed anti-aircraft gun made by Oerlikon Contraves (renamed as ''Rheinmetall Air Defence AG'' following the merger with Rheinmetall in 2009). The system was originally designated '''2 ZLA/353 ML''' but this was later changed to '''GDF-001'''. It was developed in the late 1950s and is used by around 30 countries.<ref name="urlGDF | Weaponsystems.net">{{cite web |url=https://old.weaponsystems.net/weaponsystem/EE02%20-%20GDF.html |title=GDF &#124; Weaponsystems.net }}</ref>

==Design and development==
The system uses twin [[Engineering:Autocannon|autocannon]]s, firing 35×228mm NATO-standard ammunition. It was originally designated 353 MK and is now designated as the KD series. The same KD series 35mm cannons are used in the [[Engineering:Leopard 1|Leopard 1]] based Gepard and [[Engineering:Type 74|Type 74 tank]] based [[Engineering:Type 87 self-propelled anti-aircraft gun|Type 87 SPAAG]] and [[Engineering:Marksman anti-aircraft system|Marksman]] [[Engineering:Self-propelled anti-aircraft weapon|self-propelled anti-aircraft guns (SPAAG)]]. The system could be paired with the off-gun (remote) ''Super Fledermaus'' fire control radar, which in the late 1970s was upgraded to the ''Skyguard'' system. The weapons were aimed either directly, by way of an advanced sighting system, or automatically, by locking onto the target with radar. Early models carried 112 rounds ready to fire, and an additional 126 stored on the chassis as reloads. Later versions with automated reloading carry 280 rounds total. A typical engagement burst is 28 rounds.<ref name=":0" />

In 1980 an upgraded model, the GDF-002 was produced, which featured an improved sight, and the ability to be directed by an off-gun digital control system. A few years later a third version of the system was being produced, the GDF-003, which was broadly similar to the GDF-002, but included some enhancements like self-lubricating weapons and integrated protective covers.

In 1985 a further upgraded model was produced, the GDF-005, which was introduced, featuring the ''Gunking'' 3D computer-controlled sight with an integrated laser range-finder and digital control system. The GDF-005 also introduced an automated ammunition-handling system, which eliminated the need for the two reloaders, reducing the crew from 3 to 1.<ref name=":0" />

The guns are usually transported by a 5-tonne 6×6 truck.

===KD series cannons===
[[File:FlAK85.JPG|thumb|left|An Austrian GDF-005 (FIAK85) gun system. Note the muzzle velocity measuring device on the muzzle of each gun]]
Development of the KD series cannon began around 1952 soon after Oerlikon calculated that 35&nbsp;mm was the optimum calibre for an anti-aircraft gun. The KD series cannons were a design adapted from the post-war 20&nbsp;mm KAA 204 Gk cannon. Several designs were developed, including a water-cooled design, designated Mk 352, which was tested by the U.S. Navy.
The final design was the Mk 323, which was developed in two variants, a belt-fed version the KDA, and a linkless version the KDC, fed by seven-round clips. Both designs are gas-operated, with a propped-lock locking system.<ref name="chinn">George M. Chinn, ''The Machine Gun'', Volume V</ref>

===Super Fledermaus===
[[File:Gepard 1a2 overview.jpg|thumb|A Gepard SPAAG of the German Army]]
The Super Fledermaus fire control system was designed and built by the then separate Contraves company. It consists of a four-wheeled towed trailer with an E/F band [[Physics:Pulse-Doppler radar|pulse doppler]] [[Engineering:Radar configurations and types|search radar]] with a range of around 15&nbsp;km and a pulse doppler tracking radar operating in the J band, also with a range of 15&nbsp;km. It was also used as the fire control system on the Gepard SPAAG.

===Skyguard===
[[File:FLGer98 Skyguard.JPG|thumb|An Oerlikon Contraves Skyguard Radar of the Austrian Air Force]]
[[File:Skyguard-Sparrow Missile Launcher in Songshan Air Force Base Display.jpg|thumb|Four-tube Aspide/Sparrow missile launcher closeup]]
[[File:Skyguard System Set Display in Chengkungling Oct2011.jpg|thumb|Skyguard System Set Display in Chengkungling, Taiwan]]

The Skyguard is a fire control system  introduced in the 1960s to replace the Contraves Super Fledermaus system in the {{wipe|Swiss Air Force}}. It is produced by Oerlikon-Buehrle (now Rheinmetall Air Defence). Updated version were fielded in 1975, 1995 and 2010. It's an all weather low to medium altitude (up to 3,000 m) air defence system with the maximum effective distance of 4,000 m.

The Skyguard fire control system performs air surveillance, target acquisition, calculation of the derivative-action values and control of the twin 35&nbsp;mm guns. Pulse doppler search radar, pulse doppler tracking radar and co-axial television camera are mounted on the roof of the towed trailer. Skyguard is operated by four people. The radar is deployed quickly through the use of hydraulic systems for antenna erection. The trailer houses the crew of two and a small power generator.

A typical fire unit consists of two twin 35&nbsp;mm gun platforms with a single Skyguard fire control radar. Skyguard systems can also incorporate an optional [[Engineering:Surface-to-air missile|SAM]] module based on the GDF's mount and radar system but with the guns replaced by four missile canisters. It can be armed with either AIM-7 Sparrow, RIM-7 Sea Sparrow or [[Engineering:Aspide|Aspide]] missiles.

The Skyguard radar system was used in the German Air Force for surveillance of low-altitude flight zones. In Taiwanese service, the system includes the Sky Sentinel radar, one 35&nbsp;mm Oerlikon twin gun and an AIM-7 Sparrow Missile Launcher. Greek service the Skyguard system with RIM-7M is known as the VELOS.<ref>{{cite web |title=VELOS |url=https://www.haf.gr/en/equipment/velos/ |website=haf.gr |publisher=Hellenic Air Force |access-date=18 May 2019 |archive-url=https://web.archive.org/web/20190518173427/https://www.haf.gr/en/equipment/velos/ |archive-date=18 May 2019 |url-status=live }}</ref> In Spanish service, Toledo is a Skyguard system with [[Engineering:Aspide|Aspide]] launchers where the fire control unit has been replaced with Skydor from Navantia.

==Combat history==
* 1982: The system was widely used by {{wipe|Argentina}} forces during the Falklands War. The Skyguard radar system was employed by the 601 Antiaircraft Artillery Group and the Super Fledermaus by the 1st Group of the {{wipe|Argentinian Air Force}}. The Skyguard succeeded in shooting down a Sea Harrier (XZ450) on 4 May 1982 at Goose Green. This resulted in a shift of tactics, so that British aircraft largely operated outside the weapons system's range. An RAF Harrier (XZ988) was shot down by these cannons again over Goose Green on 27 May.<ref>Pook, page 109</ref> The system was also employed in direct fire mode against British paratroopers during the Battle of Goose Green, killing two and wounding 11 and stopping the advance of two companies.<ref>[http://www.britains-smallwars.com/Falklands/David/Goosegreen.htm  "Goose Green: The Argentinian Story"] {{webarchive|url=https://web.archive.org/web/20131029202548/http://www.britains-smallwars.com/Falklands/David/Goosegreen.htm |date=2013-10-29 }} by David Aldea. British Small Wars website</ref><ref>Reynolds, David (2002). ''Task force: the illustrated history of the Falklands War''.  Sutton, p. 150. {{ISBN|0-7509-2845-X}}</ref> The guns were involved in two deadly friendly fire incidents during the campaign. The first took place on 1 May 1982, when a GADA 601 battery fired three burst of 35&nbsp;mm rounds at an Argentine Mirage III attempting to make an emergency landing at Stanley,<ref>Rodríguez Mottino, p. 170</ref> after the aircraft had been already targeted by Argentine Marine Hispano-Suiza HS-831 30mm guns deployed along the town. The aircraft fell in flames north of the airport, killing the pilot.<ref>[http://cronistaurbano.misionesonline.net/2009/08/06/el-derribo-del-primer-avion-argentino-en-malvinas/ ''El derribo del primer avión argentino en Malvinas''] {{webarchive|url=https://web.archive.org/web/20110723210539/http://cronistaurbano.misionesonline.net/2009/08/06/el-derribo-del-primer-avion-argentino-en-malvinas/ |date=2011-07-23 }} {{in lang|es}}</ref> The other friendly shootdown occurred at Goose-Green, when one A-4 Skyhawk flew by mistake over a banned zone, and was shot down with the loss of the pilot. The Argentine Air Force conceded that this time the incident was triggered by the pilot's navigation error.<ref>Fernández Reguera, José (1987). ''La Guerra de las Malvinas''. Ed. Fernández Reguera, p. 572 {{in lang|es}}</ref> The Skyguard radars were targeted by the {{wipe|Royal Air Force}} during Operation Black Buck on 31 May and 3 June. One Skyguard radar was destroyed by shrapnel from a Shrike missile strike and four operators died as a result. Another Harrier (XW919) was presumably hit by 35&nbsp;mm splinters over Sapper Hill on 12 June and sustained heavy damage.<ref>"During the attack, MacLeod's aircraft was hit by shrapnel which penetrated the rear equipment bay area of the aircraft and fractured the aft reaction control air pipe. On decelerating to the hover during the recovery, this caused a fire to start in the rear equipment bay and smoke was seen coming from the aircraft. Fuel indications suggested a considerable fuel leak at the same time. MacLeod executed a very quick and professional landing in worrying circumstances. Having landed-on, the fire was extinguished by the ground crew." [http://www.raf.mod.uk/falklands/cr1206.html#prof RAF diaries, 12 June entry] {{webarchive|url=https://web.archive.org/web/20150207072325/http://www.raf.mod.uk/falklands/cr1206.html |date=2015-02-07 }}</ref><ref>{{in lang|es}} ''En uno de esos ataques -12 de Junio- el enemigo en vuelo rasante (150 mts. del suelo) descargó todos sus cohetes sobre el cañón: resultaron seis heridos leves y fue "tocado" por la propia artillería antiaérea; uno de los sirvientes descargó sobre la máquina enemiga su fusil FAL; el cañón continuó en servicio.'' Rodríguez Mottino, page 91</ref> The aircraft was later declared out of service. There was a further direct-fire mission conducted against British troops on Wireless Ridge, just hours before the Argentinian surrender.<ref>Pook, page 162</ref> After being disabled by their operators the guns were captured by British forces. Fifteen guns and five Skyguard units were captured and shipped back to Britain in "Operation Skyguard". Four of the Skyguard sets were in good enough condition to be refurbished by BMARC in Britain with the fifth being damaged by its operators prior to capture so severely that refurbishment was not economically viable. Twelve guns and four Skyguard radars were put into British service operated by a reserve wing of the RAF Regiment 1339 wing Royal Auxiliary Air Force, comprising 2729 Squadron and 2890 Squadron {{wipe|Royal Auxiliary Air Force}} Regiment, based at RAF Waddington with an additional two new Skyguard units being procured from the Manufacturer. The RAuxAF Regiment used these guns and radar for about 10 years but defence cuts, coupled with the rising cost of ammunition and replacement gun barrels, forced the withdrawal from service of the very popular and reliable system.<ref>{{cite web|url=https://api.parliament.uk/historic-hansard/written-answers/1985/jan/31/falklands-campaign-captured-weapons|title=Falklands Campaign (Captured Weapons)  |website=Parliamentary Debates (Hansard)|access-date=8 July 2008|archive-url=https://web.archive.org/web/20090201174807/http://hansard.millbanksystems.com/written_answers/1985/jan/31/falklands-campaign-captured-weapons|archive-date=1 February 2009|date=31 January 1985|url-status=live}}</ref><ref>{{cite web|url=http://www.britains-smallwars.com/Falklands/Argentineweapons.htm#35mm|title=Britains Small Wars - Argentine Weapons|url-status=dead|archive-url=https://web.archive.org/web/20090201092905/http://www.britains-smallwars.com/Falklands/Argentineweapons.htm#35mm|archive-date=2009-02-01}}</ref>  One of the guns is on display at the RAF Regiment Heritage Centre at RAF Honington, and the Skyguard radar system is still in use by the RAF to monitor military low flying in the UK.{{citation needed|date=March 2018}}
* 12 October 2007: Nine South African National Defence Force (SANDF) soldiers were killed and 14 injured by the system during a training exercise at the SANDF Battle School at Lohatla in the Northern Cape province. A line of eight cannons were engaging a tank hulk in manual ground fire with the guns at low elevation and the maximum traverse of the barrels secured by safety poles and tethers. The rightmost gun jammed while firing and had to be repaired by technicians. Shortly after the gun was cleared to fire again, the gun malfunctioned, entered automatic mode, broke through the traversal-restriction safety mechanisms and began firing, striking the other guns along the firing line.  Initial reports suggested that the malfunction was caused when the gun underwent an unexplained [[Engineering:Hang fire|hang fire]] of the explosive 35mm ammunition in the magazines, causing the turret to swing uncontrolled through 360 degrees, firing wildly until it exhausted its remaining ammunition. A statement issued by the South African Defense Minister, Mosiuoa Lekota, however, stated that the gun had inexplicably traversed 90 degrees to the left, breaking through the safety mechanisms, and fired only a {{frac|1|8}}-second-long burst, striking all of the soldiers located on the right-hand side of their guns.<ref>{{cite magazine|url=http://blog.wired.com/defense/2007/10/robot-cannon-ki.html|title=Robot Cannon Kills 9, Wounds 14 - WIRED|magazine=Wired|access-date=2007-10-19|archive-url=https://web.archive.org/web/20090403071950/http://blog.wired.com/defense/2007/10/robot-cannon-ki.html|archive-date=2009-04-03|url-status=live|last1=Shachtman|first1=Noah}}</ref><ref>{{cite web|url=http://www.int.iol.co.za/index.php?set_id=1&click_id=13&art_id=vn20071017062134984C689240#prof|title=Google}}</ref> The accident report published by the SANDF in January 2008 blamed "undetected mechanical failure—which the manufacturers of an anti-aircraft gun allegedly kept secret". The report says the gun malfunctioned because a matchstick-sized spring pin sheared. Other sources blamed poor training and safety procedures in the SANDF.<ref>{{cite web|url=http://www.iol.co.za/index.php?set_id=1&click_id=139&art_id=vn20080126091940147C557196#prof|title=Pretoria News, p.3 on 2008 January 26|access-date=2008-01-29|archive-url=https://web.archive.org/web/20090210180401/http://www.iol.co.za/index.php?set_id=1&click_id=139&art_id=vn20080126091940147C557196#prof|archive-date=2009-02-10|url-status=live}}</ref>

==Ammunition==

{|class="wikitable" style="font-size:97%; text-align:center;"
! NATO designation || HE-T/HEI-T || HE/HEI || HEI(BF) || SAPHEI/SAPHEI-T || APDS/FAPDS || TP-T/TP || AHEAD || ATOM 35mm
|-
! Projectile weight
| {{convert|535|g|abbr=on}}
| {{convert|550|g|abbr=on}}
| {{convert|550|g|abbr=on}}
| {{convert|550|g|abbr=on}}
| {{convert|375|g|abbr=on}}
| {{convert|550|g|abbr=on}}
| {{convert|750|g|abbr=on}}
| n/a
|-
! Explosive
| {{convert|98|g|abbr=on}}
| {{convert|112|g|abbr=on}}
| {{convert|70|g|abbr=on}}
| {{convert|22|g|abbr=on}}
| n/a || n/a || n/a || n/a
|-
! Propellant
| colspan="7" align=center | {{convert|330|g|abbr=on}} || n/a
|-
! Complete round
| {{convert|1565|g|abbr=on}}
| {{convert|1580|g|abbr=on}}
| {{convert|1580|g|abbr=on}}
| {{convert|1552|g|abbr=on}}
| {{convert|1440|g|abbr=on}}
| {{convert|1580|g|abbr=on}}
| {{convert|1780|g|abbr=on}}
| {{convert|1750|g|abbr=on}}
|-
! Muzzle velocity
| {{convert|1175|m/s|abbr=on}} || {{convert|1175|m/s|abbr=on}} || {{convert|1175|m/s|abbr=on}} || {{convert|1175|m/s|abbr=on}} || {{convert|1440|m/s|abbr=on}} || {{convert|1175|m/s|abbr=on}} || {{convert|1050|m/s|abbr=on}} || {{convert|1020|m/s|abbr=on}}
|}
[[File:Militari romani in timpul tragerilor.jpg|thumb|right|Romanian soldiers firing TP rounds.]]
:'''Designation''':
:* '''HEI''': High Explosive Incendiary ('''-T'''—Tracer)
:* '''SAPHEI''': Semi-Armour Piercing High Explosive Incendiary
:* '''FAPDS''': [[Physics:Kinetic energy penetrator|Frangible Armour Piercing Discarding Sabot]]
:* '''TP''': Target Practice ('''-T'''—Tracer)
:* '''AHEAD''': Anti-missile rounds, that fire "152 heavy tungsten metal sub-projectiles".
:* '''ATOM 35mm''': Aselsan ATOM 35mm is a airburst round, that fire tungsten metal pellets as sub-projectiles. It is mainly designed to destroy [[Engineering:Cruise missile|cruise missile]]s, [[Engineering:Anti-ship missile|anti-ship missile]]s, [[Engineering:Unmanned aerial vehicle|unmanned aerial vehicle]]s, precision guided weapons, conventional and rotary-wing aircraft and various ground targets.<ref name="ATOM Aselsan Website"/><ref name="ATOM Aselsan PDF"/><ref>{{cite web |url=https://www.aselsan.com.tr/GOKDENIZ_CloseIn_Weapon_System_1178.pdf|title = GOKDENIZ|publisher= Aselsan |access-date= 26 July 2021}}</ref>
:**Specification:<ref name="ATOM Aselsan Website"/><ref name="ATOM Aselsan PDF"/>
:***Length of complete round : 387 mm
:***Fuze : Time-programmable base fuze with electronic selfdestruct function
:***Effective range : 4000 m
:***Maximum range : 12500 m

Norwegian [[Company:Nammo|Nammo]], in addition to Oerlikon, supplies at least some variants of this ammunition.<ref>{{cite news|url= https://www.overtdefense.com/2022/04/26/germany-to-transfer-gepard-anti-air-systems-to-ukraine-but-switzerland-blocks-ammunition-transfer/ |title= Germany To Transfer Gepard Anti-Air Systems to Ukraine, But Switzerland Blocks Ammunition Transfer |website= overtdefense.com |first= Matthew |last= Moss  |date= 2022-04-26 |access-date= 2022-11-02}}</ref><ref>{{cite web| url= https://www.nammo.com/product/our-products/ammunition/medium-caliber-ammunition/35-mm-series/ |title= 35 mm-series |website= nammo.com |access-date= 2022-11-02}}</ref> Norwegian ammunition was supplied to Ukraine in 2022 for use in the GDF guns in its [[Engineering:Flakpanzer Gepard|Flakpanzer Gepard]] anti-aircraft systems, but it was found not to be compatible, requiring modification.<ref>{{Cite news| url=https://bulgarianmilitary.com/amp/2022/07/31/norway-delivered-gepard-spaag-35mm-shells-are-useless-in-ukraine/ |title= Norway-delivered Gepard SPAAG 35mm shells are useless in Ukraine |website= BulgarianMilitary.com |first= Boyko |last= Nikolov |date=2022-07-31 |access-date=2022-11-01}}</ref>

==Versions==
[[File:Japanese L90 or GDF-002 35 mm twin cannon.jpg|thumb|A Japanese built version of the gun in travelling position]]
[[File:Oerlikon 35mm twin cannon.jpg|thumb|Under tow, an Oerlikon 35mm twin cannon of the Republic of Singapore Air Force]]
[[File:JGSDF type 87 Self-Propelled Anti-Aircraft Gun 02.jpg|thumb|Japanese Type 87 SPAAG]]
[[File:Marksman SPAAG.jpg|thumb|Finnish ITPSV 90]]
[[File:Kalustoesittely itsenäisyyspäivä 2015 17 Leopard 2 Marksman.JPG|thumb|Finnish ITPSV Leopard 2 Marksman]]
[[File:PZA Loara zdjecie 489 5980.jpg|thumb|The PZA Loara-A anti-aircraft vehicle]]
* '''GDF-001''' / '''2 ZLA/353 MK''': XABA sight
* '''GDF-002''': Introduced in 1980. Improved Ferranti sight and digital data bus. The gun has 112 rounds ready and 126 in reserve (238 rounds total)
* '''GDF-003''': Minor enhancements including protective covers and automatic weapon lubrication.
* '''GDF-005''': Introduced in 1985. Fitted with ''Gunking'' 3D computer-controlled sight with a laser range finder and digital fire control system. Integrated power supply and diagnostics. 280 rounds on the gun and an automatic re-loading system.
* '''GDF-006''': GDF-001/002/003 upgraded with ''AHEAD'' system.
* '''GDF-007''': GDF-005 upgraded with ''AHEAD'' system.
* '''GDF-009''': Unveiled at IDEF 2015, held in May 2015 in Istanbul. To date, its exterior significantly changed, although the installation has retained the design of the original serial versions of the systems. Unlike other variants, this one relies on an internal power source. The GDF-009 model is based on a four-wheeled carriage, and is raised off the ground by three stabilisers when deployed in the firing position. It also features an automatic levelling system that can compensate for a maximum tilt angle of up to 7°.Mounted on the forward part of the carriage is the integrated battery, which functions as the gun's power supply unit and can be recharged from an external source if required.<ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |title=New anti-aircraft gun Oerlikon GDF-009 from Rheinmetall |url= https://weaponews.com/news/11731-new-anti-aircraft-gun-oerlikon-gdf-009-from-rheinmetall.html|work=WeaponNews|location=Unknown |date=2017-07-25 |access-date=2019-09-04 }}</ref>
* '''AHEAD''': An upgrade for the GDF series guns built around a special projectile which explodes at a pre-calculated point in front of the target, sending a cone of 152 tungsten sub-projectiles at the target. Used by Canada, Pakistan, Greece, Oman, Spain, Taiwan, and Chile (unconfirmed).
*'''MKE GDF-003B''': Turkish version of 35&nbsp;mm GDF series. The gun of the system manufactured under licence by Turkish company Mechanical and Chemical Industry Corporation.<ref>{{cite web |title=35 mm Twin Barrel Anti-Aircraft Gun: GDF-003B |url=https://www.mkek.gov.tr/en/product.aspx?id=52&source=Products&pid=1454 |website=www.mkek.gov.tr |access-date=26 July 2021 |archive-date=25 July 2021 |archive-url=https://web.archive.org/web/20210725160235/https://www.mkek.gov.tr/en/product.aspx?id=52&source=Products&pid=1454 |url-status=dead }}</ref><ref name="SSB 35MM GUN">{{cite web|url= https://www.ssb.gov.tr/urunkatalog/en/238/|title= GUNS and HOWITZERS: 35MM TWIN BARREL ANTI AIRCRAFT GUN|publisher= TURKISH DEFENCE INDUSTRY PRODUCT CATALOGUE|access-date= 8 July 2021|archive-date= 27 January 2020|archive-url= https://web.archive.org/web/20200127143920/https://www.ssb.gov.tr/urunkatalog/en/238/|url-status= dead}}</ref>   
*'''MKE/Aselsan GDF-003B Modernized''': MKE GDF-003B system modernized by another Turkish company Aselsan.<ref name="SSB 35MM GUN"/>  MKE made 35mm guns linked with an Aselsan made Fire and Command Control System. The system has similarities with Skyguard system. The Fire and Command Control System consists of Aselsan made 3D search radar, fire control radar, electro-optical (E/O) sensors and other electronics. Each weapons system can fire up to 1100 rpm (2 x 550rpm) to an effective range of 4&nbsp;km.<ref name="GDF-003B Modernized Aselsan Website">{{cite web|url=https://www.aselsan.com.tr/en/capabilities/air-and-missile-defense-systems/self-propelled-and-air-burst-munition/modernization-of-35-mm-towed-air-defense-guns|title = Modernization of 35 mm Towed Air Defense Guns |publisher= Aselsan |access-date= 26 July 2021}}</ref><ref name="GDF-003B Modernized Aselsan PDF">{{cite web|url=https://www.aselsan.com.tr/0a9edde5-0e87-442c-99cb-0b2a0c0352d8.pdf|title = Modernization of 35 mm Towed Air Defense Guns|publisher= Aselsan |access-date= 26 July 2021}}</ref> The upgradation enables the system to fire Aselsan ''ATOM 35mm'' airburst round which explodes at a pre-calculated point in front of the target, sending a cone of tungsten pellets at the target.<ref name="ATOM Aselsan Website">{{cite web|url=https://aselsan.com.tr/en/capabilities/land-and-weapon-systems/smart-munition-and-active-protection-systems/atom-35mm-airburst-ammunition|title = ATOM 35mm Airburst Ammunition|publisher= Aselsan |access-date= 21 July 2021}}</ref><ref name="ATOM Aselsan PDF">{{cite web|url=https://www.aselsan.com.tr/ATOM_35_mm_Air_Burst_Ammunition_4236.pdf|title = ATOM|publisher= Aselsan |access-date= 21 July 2021}}</ref> The gun can also fire HEI and TP-T  ammunitions.<ref name="GDF-003B Modernized Aselsan PDF"/> The concept of ''ATOM 35mm'' air burst ammunition came up in order to increase the efficiency of the gun systems against modern targets including  fixed/rotary wing aircraft, cruise missiles, [[Engineering:Air-to-surface missile|air-to-ground missiles]] and [[Engineering:Unmanned aerial vehicle|unmanned aerial vehicle]]s and other precision guided weapons.<ref name="GDF-003B Modernized Aselsan PDF"/><ref name="ATOM Aselsan Website"/><ref name="ATOM Aselsan PDF"/> Aselsan Fire and Command Control  system can also incorporate a low altitude air defense [[Engineering:Surface-to-air missile|SAM]] along with 35&nbsp;mm gun platform.<ref name="GDF-003B Modernized Aselsan PDF"/> Like the GDF-009 each gun platform equipped with the integrated battery, which functions as the gun's power supply unit and can be recharged from an external source if required.<ref name="GDF-003B Modernized Aselsan PDF"/>
* '''[[Engineering:KORKUT|KORKUT]]''': Turkish  Self-propelled ([[Engineering:Self-propelled anti-aircraft weapon|SPAAG]]) variant designed by Aselsan. The system developed from modernized GDF-003B and based around the [[Engineering:Amphibious vehicle|amphibious capable]] FNSS ACV-30. KDC-02 cannon of the system manufactured under licence by MKE.<ref>{{Cite news|url=http://savunmaveteknoloji.com/ilk-korkut-sistemi-teslim-edildi/|title=İlk "KORKUT" sistemi teslim edildi|newspaper=SVT {{!}} Savunma ve Teknoloji|access-date=2021-07-26| language= tr|archive-url=https://web.archive.org/web/20170202000224/http://savunmaveteknoloji.com/ilk-korkut-sistemi-teslim-edildi/|archive-date=2017-02-02|url-status=dead}}</ref> Each [[Engineering:KORKUT|Korkut]] system compromises of a command and control vehicle and three weapons platform vehicles. The command and control vehicle has the 3D search radar with an effective radar range of 70&nbsp;km. Each weapon platform vehicle carries enclosed twin 35&nbsp;mm cannons, fire control radar and electro-optical (E/O) sensors.<ref name="KORKUT Aselsan Website">{{cite web|url=https://www.aselsan.com.tr/en/capabilities/air-and-missile-defense-systems/self-propelled-and-air-burst-munition/korkut-self-propelled-air-defense-gun-system|title = KORKUT Self Propelled Air Defense Gun System |publisher= Aselsan |access-date= 26 July 2021}}</ref><ref name="KORKUT Gun Vehicle Aselsan PDF">{{cite web|url=https://www.aselsan.com.tr/KORKUT_SSA_7426.pdf|title = KORKUT SSA|publisher= Aselsan |access-date= 26 July 2021}}</ref><ref name="KORKUT Search Radar Vehicle Aselsan PDF">{{cite web|url=https://www.aselsan.com.tr/KORKUT_KKA_7187.pdf|title = KORKUT KKA|publisher= Aselsan |access-date= 26 July 2021}}</ref>
* '''[[Engineering:Aselsan GOKDENIZ|Aselsan GOKDENIZ]]''': [[Engineering:Close-in weapon system|CIWS]] version of KORKUT. The system's primary purpose is to defend against [[Engineering:Sea skimming|sea skimming]] [[Engineering:Anti-ship missile|anti-ship missile]]s, [[Engineering:Unmanned aerial vehicle|unmanned aerial vehicle]]s and other precision guided weapons.<ref name="GOKDENIZ Aselsan PDF">{{cite web |url=https://www.aselsan.com.tr/GOKDENIZ_CloseIn_Weapon_System_1178.pdf|title = GOKDENIZ|publisher= Aselsan |access-date= 26 July 2021}}</ref><ref name="SSB GOKDENIZ">{{cite web|url= https://www.ssb.gov.tr/urunkatalog/en/106/|title= WEAPONS and TURRETS for NAVAL PLATFORM: GOKDENIZ|publisher= TURKISH DEFENCE INDUSTRY PRODUCT CATALOGUE|access-date= 26 July 2021|archive-date= 22 November 2019|archive-url= https://web.archive.org/web/20191122030313/https://www.ssb.gov.tr/urunkatalog/en/106/|url-status= dead}}</ref>
* '''Gepard''': Self-propelled ([[Engineering:Self-propelled anti-aircraft weapon|SPAAG]]) version of the system based around the [[Engineering:Leopard 1|Leopard 1]].
* '''[[Engineering:Marksman anti-aircraft system|Marksman]]''': Self-propelled version of the system based around the Marksman turret, which could be fitted on numerous tank chassis. The only model that went into production was a version based on the T-55AM chassis for Finland, seven systems of the '''ITPSV 90 Marksman''' were produced. After having been moved to reserve storage since 2010, the Marksman turrets had their electronics modernized and were transferred over to Leopard 2 chassis in 2015,<ref>{{cite web|title=Armeija ottaa vanhojen Marksman-vaunujen tykkitornit uuteen käyttöön|trans-title=Army takes old Marksman tank turrets to new use|language=fi|first=Jarmo|last=Huhtanen|url=https://www.hs.fi/kotimaa/art-2000002811544.html|url-access=subscription|access-date=14 April 2021|date=25 May 2015|website=Helsingin Sanomat|publisher=Sanoma Media Finland|url-status=live|archive-url=https://web.archive.org/web/20170419013744/http://www.hs.fi/kotimaa/art-2000002811544.html|archive-date=19 April 2017}}</ref> creating the '''ITPSV Leopard 2 Marksman'''.<ref name="PSPR2015">{{cite web|url=http://puolustusvoimat.fi/wcm/a2748e00495d6be1a9e0a98833fba23b/Toimintanaytoksen_materiaalitiedot_5+8+2015.pdf?MOD=AJPERES|archive-url=https://web.archive.org/web/20151005155147/http://www.puolustusvoimat.fi/wcm/a2748e00495d6be1a9e0a98833fba23b/Toimintanaytoksen_materiaalitiedot_5+8+2015.pdf?MOD=AJPERES|title=Maavoimien liikkuvuuden ja tulivoiman roll out Panssariprikaatissa 5.8.2015 – Esiteltävä kalusto|trans-title=Army Mobility and Firepower roll out in Armoured Brigade, 5 August 2015 – Equipment Presentation|publisher=Finnish Defence Forces|language=fi|date=5 August 2015|archive-date=5 October 2015|access-date=14 April 2021}}</ref>
* '''Type 87''': Japanese SPAAG using the system.
* '''[[Engineering:PZA Loara|PZA Loara]]''': Polish SPAAG based on the PT-91 tank.
* '''Type 90 (PG99)''': Chinese licensed copy of GDF-002.<ref>{{cite web|title=Type 90 Twin-35mm Towed Anti-Aircraft Artillery|url=http://www.sinodefence.com/army/antiaircraft/type90towed35mm.asp|publisher=sinodefence.com|access-date=2013-04-24|url-status=dead|archive-url=https://web.archive.org/web/20130404070150/http://www.sinodefence.com/army/antiaircraft/type90towed35mm.asp|archive-date=2013-04-04}}</ref>  The PG99 is a towed anti-aircraft gun suitable for point and coastal air defence. It is usually deployed near military bases, airfields, tunnels, islands, and along the coast to defend Sea Land of Communication (SLOC), ports, bridges and other important assets.<ref>{{cite news|title=Wide range of defence solutions available from ChinaPoly Technologies Inc|url=http://www.janes.com/events/exhibitions/africa-aerospace-defence-2012/news/sept-20/Wide-range-of-defence-solutions-from-ChinaPoly.aspx|access-date=20 April 2013|date=20 September 2012|publisher=Jane's Information Group|archive-url=https://web.archive.org/web/20121012062823/http://www.janes.com/events/exhibitions/africa-aerospace-defence-2012/news/sept-20/Wide-range-of-defence-solutions-from-ChinaPoly.aspx|archive-date=12 October 2012|url-status=live}}</ref>
*'''MAA-01''': Myanmar's locally made variant using Chinese GDF guns.Similar to Type-90.<ref name="auto">{{cite web|url=http://armstrade.sipri.org/armstrade/page/trade_register.php|title=SIPRI Trade Register|publisher=Stockholm International Peace Research Institute}}</ref>
* '''CS/SA1''': Chinese upgrade of GDF-002.<ref>{{cite news|title=Pakistan Acquires Chinese Made Air Defence Artillery|url=http://www.kanwa.com/dnws/showpl.php?id=725|access-date=2013-04-20|date=2013-03-28|publisher=Kanwa Daily News|url-status=dead|archive-url=https://web.archive.org/web/20131029203734/http://www.kanwa.com/dnws/showpl.php?id=725|archive-date=2013-10-29}}</ref> Mounted on the 6×6 SX2190 truck, the PG99 (CS/SA1) is a [[Engineering:Self-propelled anti-aircraft weapon|self-propelled]] variant of the Type 90 35&nbsp;mm AA system, previously available only as a towed AA piece.<ref>{{cite web|last=Andrew|first=Martin|title=PLA Mechanised Infantry Division Air Defence Systems / PLA Point Defence Systems|date=16 March 2009|pages=1|url=http://www.ausairpower.net/APA-PLA-Div-ADS.html|access-date=20 April 2013|archive-url=https://web.archive.org/web/20120503214842/http://ausairpower.net/APA-PLA-Div-ADS.html|archive-date=3 May 2012|url-status=live}}</ref>
* '''Type 09 SPAAA''': Self-propelled version of the system based around the Type 90. First appeared in 2015 China Victory Day Parade.
* '''Samavat''': Iranian version of these guns with night vision sight and used with Skyguard & Super Fledermaus FC radars.
* '''Amoun''': Egyptian version of Skyguard & Sparrow SAM.

==Operators==
[[File:35mmFlab.png|thumb|A deployed Swiss GDF-005]]

* {{ARG}}: 38 GDF-002 Army with Skyguard, 6 GDF-002 Air Force with Super Fledermaus FC radar.
* {{AUT}}: 74 GDF-005 Army, Air Force 18 GDF-005 with 37 Skyguard FC radar
* {{BHR}}: 12 GDF-005 units, used with Skyguard FC radar.
* {{BAN}}: 4-8 Oerlikon GDF-009 anti aircraft gun systems have been ordered with Skyguard 3 fire control radar.<ref>{{cite web| url=https://dgdp.gov.bd/dgdp/AP_TEN/s_doc/2615.pdf|title=Technical Specification and Other Requirements for Item SER No 1. Carts High Explosive Incendiary (HEI) for Radar Control Air Defence Gun System 35 mm Oerlikon GDF 009/Skyguard 3,QTY-1,000 NOS|publisher=DGDP|access-date=3 September 2019|archive-url=https://web.archive.org/web/20190903175249/https://dgdp.gov.bd/dgdp/AP_TEN/s_doc/2615.pdf|archive-date=3 September 2019}}</ref> In 2019, the gun systems have been tested at Cox's Bazar.<ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |title=Newly Addition in Bangladesh Army Orelikon Radar Controlled Gun Test Firing Held at Coxbazar|url=https://www.ispr.gov.bd/en/newly-addition-in-bangladesh-army-orelikon-radar-controlled-gun-test-firing-held-at-coxbazar/#pll_switcher|language=Bangla|work=ISPR |location=Bangladesh |date=13 October 2019 |access-date=14 October 2019}}</ref><ref>{{Cite web|url=https://today.thefinancialexpress.com.bd/metro-news/oerlikon-radar-controlled-gun-1570990874|title=Oerlikon Radar Controlled Gun|last=Anti-Aircraft Gun|first=Oerlikon GDF 009|date=October 14, 2019|website=The Financial Express|url-status=bot: unknown|archive-url=https://web.archive.org/web/20191017062929/https://today.thefinancialexpress.com.bd/metro-news/oerlikon-radar-controlled-gun-1570990874|archive-date=October 17, 2019|access-date=October 17, 2019}}</ref>
* {{BRA}}: 38 GDF-001 with updated Super Fledermaus and Brazilian made Skyguard FC radars. To be fitted with the Saber M60 radar.
* {{CMR}}: GDF-002 and Type-90 units<ref>{{cite web|last1=de Cherisey|first1=Erwan|title=New Cameroonian air-defence capabilities revealed|url=http://www.janes.com/article/62239/new-cameroonian-air-defence-capabilities-revealed|website=IHS Jane's 360|access-date=13 July 2016|location=Paris|language=en|date=13 July 2016|archive-url=https://web.archive.org/web/20170614172912/http://www.janes.com/article/62239/new-cameroonian-air-defence-capabilities-revealed|archive-date=2017-06-14|url-status=dead}}</ref>
* {{CAN}}: 20 GDF-005 units and 10 Skyguard FC radars in stock for emergency
* {{CHI}}: 24 GDF-005/007 units, used with Skyguard FC radar.<ref>[http://farm6.static.flickr.com/5310/5591150698_a74555bdd4_b.jpg GDF-007 FACH]</ref>
* {{CHN}}: licensed copy of GDF-002 as the Type 90, 400 units with Skyguard FC radar<ref>[http://www.sinodefence.com/army/antiaircraft/type90towed35mm.asp Type 90 Twin-35mm Towed Anti-Aircraft Artillery.] {{webarchive|url=https://web.archive.org/web/20130404070150/http://www.sinodefence.com/army/antiaircraft/type90towed35mm.asp |date=2013-04-04 }} Retrieved on August 1, 2008.</ref>
* {{COL}}: 75 GDF-005 units in reserve
* {{CYP}}: 30 GDF-005 units used with Skyguard and Aspide SAM
* {{ECU}}: 30 GDF-003 units
* {{EGY}}: 72 Amoun units used with Skyguard and Sparrow SAM
* {{FIN}}: 16 units. Known as 35 ITK 88
* {{GER}}: On the Flugabwehrkanonenpanzer Gepard (self-propelled anti-aircraft gun)
* {{GRE}}: 24 GDF-002 units upgraded to GDF-006 AHEAD, 12 upgraded Skyguard FC radars, used with Sparrow SAM
* {{IRN}}: 92 GDF-002 units. Iran produces its own version called Samavat. Used with Skyguard & Super Fledermaus FC radars.
* {{INA}}: 8 GDF
* {{JPN}}: some 70 GDF-001 units, used with updated Super Fledermaus FC radars. Made under a joint venture with Japan Steel Works for the 35mm gun and [[Company:Mitsubishi Electric|Mitsubishi Electric Corporation]] for the rest of the system<ref>{{in lang|ja}} [http://rightwing.sakura.ne.jp/equipment/jgsdf/airartillery/35mm-l90/l90.html 35mm 2連装高射機関砲 L-90.] {{webarchive|url=https://web.archive.org/web/20081205175953/http://rightwing.sakura.ne.jp/equipment/jgsdf/airartillery/35mm-l90/l90.html |date=2008-12-05 }} Retrieved on August 1, 2008.</ref> 52 On the Type 87 (self-propelled anti-aircraft gun)
* {{KOR}}: 36 GDF-003 units, used with Skyguard FC radar.
* {{KUW}}: 12 GDF-005 (Amoun) units, used with Skyguard and Sparrow SAM
* {{MYS}}: 28 GDF-005 units, used with Skyguard FC radar.
* {{MYA}}: 10 locally made MAA-01, (Type-90) as of 2017.<ref name="auto"/>
* {{NGA}}: 16 GDF-002 units
* {{OMA}}: 10 GDF-005 units AHEAD modified, used with Skyguard FC radar.
* {{PAK}}: estimated 180 GDF-005 units, 60 units AHEAD modified, used with Skyguard FC radar.
* {{ROU}}: 43 Flugabwehrkanonenpanzer Gepard systems and 72 GDF-003 units
* {{SAU}}: 128 GDF-005 modified units. Used with Skyguard FC radars.
* {{SIN}}: 58 units : 34 GDF-001 and 24 GDF-002 units. Fire-control radar locally upgraded<ref>{{cite web|url=http://armstrade.sipri.org/armstrade/page/trade_register.php|title=SIPRI arms transfer database|date=18 June 2011|publisher=Stockholm International Peace Research Institute|access-date=18 June 2011|archive-url=https://web.archive.org/web/20100414022558/http://armstrade.sipri.org/armstrade/page/trade_register.php|archive-date=14 April 2010|url-status=live}}</ref> 
* {{RSA}}: 102 GDF-002 (100 Mk1 GDF-002 units in 2004 were sold for $500 000) + 48 modified GDF-005 units. Upgrading to the [[Engineering:Skyshield|Skyshield]] system, GDF-006 AHEAD and GDF-007 AHEAD standard by 2017. Some 169 Oerlikon GDF-00? were acquired by the SADF along with 75 Super Fledermaus FC radars.
* {{ESP}}: 92 GDF-007 upgraded from GDF-005 between 2003 and 2006. With 27 Skydor and 18 Skyguard FC radars.<ref>{{in lang|es}} [http://www.ejercito.mde.es/en/unidades/Madrid/cgmaaa/Organizacion/index.html Spanish Minister of Defense official website.] {{Webarchive|url=https://web.archive.org/web/20160624021912/http://www.ejercito.mde.es/en/unidades/Madrid/cgmaaa/Organizacion/index.html |date=2016-06-24 }} May 2008.</ref>
* {{SUI}}: Some 24 GDF-005 modified units (from a total of 264 GDF-001/002 units) used with Skyguard FC Radar.
* {{TWN}}: 24 Skyguard "Sky Sentinel" fire control radars linked to some 50 GDF-003 35&nbsp;mm twin guns. Upgraded to GDF-006 to fire AHEAD rounds since 2009.
* {{THA}}: 8 GDF-007, used with 4x Skyguard 3 FC radar units.
* {{TUR}}: 35&nbsp;mm Oerlikon gun produced under licence by MKE.<ref name="SSB 35MM GUN"/><ref>{{cite web|url=http://www.mkek.gov.tr/tr/Urunler.aspx?UretimYeriID=0&UrunID=94&AnaKategori=107&AltKategori=123&EnAltKategori=|title=MKEK - Makina ve Kimya Endüstrisi Kurumu|website=www.mkek.gov.tr|access-date=2014-05-23|archive-url=https://web.archive.org/web/20141217072207/http://www.mkek.gov.tr/tr/Urunler.aspx?UretimYeriID=0&UrunID=94&AnaKategori=107&AltKategori=123&EnAltKategori=|archive-date=2014-12-17|url-status=live}}</ref> 120 GDF-003 units,<ref>{{cite web|url=http://www.globalsecurity.org/military/world/europe/tu-army-equipment.htm|title=Turkey - Major Army Equipment|first=John|last=Pike|website=www.globalsecurity.org|access-date=2014-05-23|archive-url=https://web.archive.org/web/20131202230511/http://www.globalsecurity.org/military/world/europe/tu-army-equipment.htm|archive-date=2013-12-02|url-status=live}}</ref> Turkish version known as '''MKE GDF-003B'''.<ref name="SSB 35MM GUN"/> Multiple gun systems upgraded to '''GDF-003B Modernized''' with Aselsan Fire and Command Control System by Aselsan.<ref name="SSB 35MM GUN"/><ref name="GDF-003B Modernized Aselsan Website"/><ref name="GDF-003B Modernized Aselsan PDF"/>
* {{UKR}}: 30 on the Flugabwehrkanonenpanzer Gepard SPAAGs.
* {{UAE}}: 30 GDF-005 units
* {{UK}}: 15 GDF-002 35mm twin guns were captured during the Falklands War along with six Skyguard and one Super Fledermaus FC Radars. One of the Skyguard radars was destroyed from a Shrike missile strike during the conflict. Currently four of these Skyguard fire control systems are being used to detect UK military aircraft exceeding flight restrictions over residential areas.<ref>{{citation |url=https://publications.parliament.uk/pa/cm200102/cmhansrd/vo020211/debtext/20211-05.htm |title=Skyguard |work=House of Commons Debates |publisher=Hansard |date= 11 Feb 2002 |at=31902 |url-status=live |archive-url=https://web.archive.org/web/20180319151049/https://publications.parliament.uk/pa/cm200102/cmhansrd/vo020211/debtext/20211-05.htm |archive-date=19 March 2018 }}.</ref> GDF-002 guns now in storage and in a few military museums in the UK.

==See also==
* [[Engineering:List of artillery|List of artillery]]
* [[Engineering:List of artillery by type#Anti-aircraft artillery|List of anti-aircraft artillery]]
* [[Engineering:List of artillery by country#Germany|List of artillery of Germany]]
* [[Engineering:List of artillery by country#Switzerland|List of artillery of Switzerland]]
;Related development
* Oerlikon Millennium 35 mm Naval Revolver Gun System
* Type 09 SPAAA

==References==
;Notes
{{reflist|30em}}

;Bibliography
{{refbegin}}
* ''Jane's Land-Based Air Defence 2005–2006'', by James C O'Halloran, {{ISBN|0-7106-2697-5}}
* ''RAF Harrier Ground Attack-Falklands'', by Jerry Pook,  {{ISBN|978-1-84415-551-4}}
* ''The Machine Gun, Volume V'', George M. Chinn
* [https://web.archive.org/web/20070311052502/http://www.rheinmetall-detec.com/index.php?lang=3&fid=1520&action=pd Rheinmetall page on 35 mm ammo]
* ''La Artillería Argentina en Malvinas'', by Horacio Rodríguez Mottino. {{in lang|es}}
* [https://gizmodo.com/gadgets/weapons/robot-cannon-goes-berserk-kills-9-312443.php Weapons: Robot Cannon Goes Berserk, Kills 9]
{{refend}}

==External links==
* [https://web.archive.org/web/20071029183211/http://www.rheinmetall-detec.de/index.php?fid=1556&lang=3&pdb=1 Official website]
* [https://archive.today/20140307024503/http://www.armyrecognition.com/germany_german_army_artillery_vehicles_systems_uk/skyguard_iii_1_oerlikon_air_defense_system_cannon_missile_technical_data_sheet_specifications.html Oerlikon Skyguard III Air Defense System on armyrecognition.com]

{{DEFAULTSORT:Oerlikon GDF}}
[[Category:Autocannon]]
[[Category:Anti-aircraft guns]]

{{Sourceattribution|Oerlikon GDF}}