In service with the SAAF since about 1995, the Kentron V4 (Radar Darter) medium-range air-to-air missile is an all-aspect beyond visual range (BVR) air-to-air radar guided missile offering an AMRAAM-level of capability. It was the primary medium range armament of the SAAF's Cheetah C fighters, but was retired together with the Cheetah in April 2008. Under existing plans, the SAAF will not have a BVRAAM for its Saab Gripen fighter force when it enters service around 2012.
The V4 is designed to provide immunity against electronic counter-measures and has an upgrade capability to meet any future change in the threat. The active radar seeker head, in conjunction with the modern radar onboard the aircraft, lets the pilot track multiple targets and launch more than one missile. It is capable of two modes: lock on before or after launch. In the lock-on before launch for short-range engagements, the seeker can be slaved to the aircraft's radar or the pilot's helmet mounted cueing system. The seeker is activated before launch and guides the missile all the way to the target .In lock-on after launch mode, for long-range engagements, the missile employs inertial guidance immediately after launch until the seeker is activated and homes in on the target.
Despite repeated reports in the international media that the V4 is a version of Israel's Rafael Derby, South African engineers working on the project have told the webmaster that there was no Israeli involvement in the design of the V4, despite the striking similarities between the two! It is believed that development of Derby began in Israel in the early 1980's, with South Africa joining the development program and providing funding a few years later.It is understood that the V4/Derby was developed jointly, with the Israeli and South African teams responsible for different components of the missile.
The V4 was due for an upgrade shortly after the Gripen was due to enter service. Given the costs and number of missiles to be used during the upgrade testing phase, it was decided to retire the V4 in April 2008, together with the retirement of the Cheetah aircraft. The Gripen is then to be armed with a new BVR missile.