AI Mk. X
The AI Mk. X or Airborne Interception radar, Mark X is a British airborne target detection (search) radar. It is a British version of the American SCR-720 radar and in game is found on British and American aircraft.
Vehicles equipped with this radar
General info / usage
Being only a target detection radar the AI Mk. X cannot track targets or provide a firing lead indicator. However it has a respectable detection range of up to 14,000 m and a rapid scanning speed taking only approximately 0.17 seconds to complete a scan.
|14,000 m||8,500 m||150 m||3 km, 9 km, 18km|
Comparison with analogues
Compared to war time radars like the German FuG 202 and FuG 220 the AI Mk. X has a much wider scanning arc and better range; however does not update instantly, unlike German radars. Compared to the post war Allied AN/APS-21 search radar the AI Mk. X has inferior range and scanning angles, but scans much faster.
Pros and cons
- Respectable 14,000 m max range
- Rapid scanning
- Decent scanning angles
- Inferior range and scanning angles to some high tier radars
The AI Mk. X (Airborne Interception radar, Mark X) is a British version of the American SCR-720 Radar. The SCR-720 was a development of the SCR-520 radar, which was in turn developed using knowledge gained from the development of the British AI Mk. VIII radar (the first operational microwave-frequency air-to-air radar). The story of the Airborne Interception (AI) family of radars began in Britain, in late 1935 with the successful testing of the Chain Home system (an early ground-based early warning radar), in which it was proven capable of detecting aircraft at ranges of over 64 km (the range would eventually improve to 160 km). Plans were soon put in place to begin building Chain Home stations along the south coast of England, in preparation for any potential air attack on Britain.
The chain home system could detect an aircraft at a maximum accuracy of one mile, but it took time to communicate this information to air-crews, meaning that by the time the information was revived, accuracy would be reduced to 5 miles (due to aircraft moving from the reported position). This would not be a problem for daylight interceptions as pilots could easily spot an aircraft 5 miles away, but would make the radar system much less effective at night. Henry Tizard, who was leading the implementation of Chain Home, began to fear that the radar system might become too effective. He predicted that if the Luftwaffe ever attacked Britain it would lead to them suffering so many losses that they would be forced to switch to night operation, in which case Chain Home would loose it's effectiveness. He raised his concerns and August 1936 a project was started to develop a radar system which could be fitted to aircraft; the plan was that at night Chain Home could guide interceptors to the general area of enemy aircraft, at which point they would switch to using their own radars to find their exact location.
In autumn 1936 the first ever airborne radar system, known as RDF 1.5 was tested, it consisted of a powerful ground based transmitters and a receiver mounted on a Handley Page Heyford biplane bomber. Although capable of detecting aircraft 80 km away the system was deemed unworkable due the need for a large number of ground based transmitters, and having only a very narrow search angle (the transmitter, receiver aircraft and target aircraft needed to be roughly in line with each other). In March 1937 the Heyford was fitted with it's own transmitter, and was able to detect targets a few miles away and in September 1937 an Avro Anson fitted with the radar proved it could be used to detect shipping nearly 10 miles away in poor weather conditions. The rest of 1937 and 1938 was spent refining the radar for ship detection and turning it into a workable system (instead of a battery powered prototype). In 1939, with the prospect of war feeling inevitable focus switched back to detecting aircraft.
Through 1939 Mk.I, Mk.II and Mk.III versions of the Airborne Interception radar were produced and tested in limited service with the RAF. All of them suffered from various problems, most notably a high minimum range,low maximum range, or inadequate scan angles. In May 1940 the Mk IV was tested, it solved all the previous problems with a maximum range of 6 km and a minimum range of only 150 m, a production order of 3,000 units was placed immediately, making the AI Mk. IV world's first airborne radar to enter service. Improved Mk. V, and Mk. VI versions of the radar saw limited RAF service.
The next major AI radar to enter service was the AI Mk. VIII. The Mk. VIII was a major redesign compared to the MK. IV. Instead of using static antennas like the Mk. IV the Mk. VIII used a spinning parabolic dish which focused the beam, improving range and reducing clutter. Critically the Mk. VIII was also the worlds first operational airborne radar to operate at microwave frequency, offering much better performance than the Mk. IV which operated on VHF radio frequency. The AI Mk. VIII entered service in 1941.
During the development of microwave frequency radars, and the AI Mk. VIII, a prototype was sent to America as part of the Tizard Mission. The Tizzard mission took place in 1940; a delegation of British scientists / engineers traveled to America to share Research and Development achievements. This plan was for American to be given access to British developments (including radar), in exchange for assistance with the war effort (provision of supplies etc.); and to allow America's vast industrial resources to exploit the R&D work completed by the UK, which Britain itself could not fully exploit due to the immediate requirements of war-related production. One of the British Scientists Edward "Taffy" Bowen remained in the US after the original visit and helped set up the MIT Radiation Laboratory which began developing airborne radars for the United States. Using the information gained from the British prototype, they made "remarkable" progress and soon produced the SCR-520 radar. The SCR-520 was designed for use in the P-70 (a fighter version A-20 Havoc) and P-61.
After the development of the AI Mk. VIII development of a new radar the AI Mk. IX began. The Mk. IX would offer better performance than the MK. VIII and would have new features including target tracking. However during a test flight on On 23 December 1942 the Beaufighter carrying the only radar prototype and Arthur Downing (the radar's lead developer) was attacked in a friendly fire incident, after being mistaken by two spitfires for a German aircraft. The Beaufighter crashed into the sea, killing Downing and destroying the prototype. The loss of Downing and the radar prototype caused a significant delay in the British radar program. Around the same time in December 1942 the American Western Electric company (which had received the contract for production of American airborne radars) provided Britain with an example of the new SCR-720 radar. It was an improved and significantly lighted SCR-520, which would fit inside British aircraft (unlike the SCR-520). With their own radar program delayed British engineers passed a number of minor suggestions and upgrades to Western Electric, resulting in the SCR-720B. Britain placed an order for 2,900 SCR-720Bs under the name AI Mk. X. The AI Mk X entered service with the RAF in August 1943, fitted on night fighter versions of the Mosquito (and later on other aircraft).
The AI Mk.X remained in service until 1957, being fitted to night fighter version of the Gloster Meteor and the Sea Venom FAW 20.
An excellent addition to the article would be a video guide, as well as screenshots from the game and photos.