The Republic of Korea Army (RoKA) has put into service all of the 36 AH-64E Apache Guardian attack helicopters ordered from Boeing in 2013 as part of a USD1.6 billion contract under the US Foreign Military Sales programme.
In 2009, South Korea showed interest in acquiring Apaches, potentially related to U.S. plans to withdraw many of its Apaches from the country. On 21 September 2012, the U.S. Congress was notified of the possible purchase of 36 AH-64D Block III Apaches, along with associated equipment and armament. The Apache competed against the Bell AH-1Z Viper and the TAI/AgustaWestland T-129; in April 2013, South Korea announced that it would purchase 36 AH-64Es. The first four AH-64Es were delivered in May 2016, and all 36 were deployed in January 2017.
Formerly known as AH-64D Block III, in 2012, it was redesignated as AH-64E Guardian to represent its increased capabilities. The AH-64E features improved digital connectivity, the Joint Tactical Information Distribution System, more powerful T700-GE-701D engines with upgraded face gear transmission to accommodate more power, capability to control unmanned aerial vehicle (UAVs), full IFR capability, and improved landing gear. New composite rotor blades, which successfully completed testing in 2004, increase cruise speed, climb rate, and payload capacity. Deliveries began in November 2011. Full-rate production was approved on 24 October 2012, with 634 AH-64Ds to be upgraded to AH-64E standard and production of 56 new-build AH-64Es to start in 2019/20. Changes in production lots 4 through 6 shall include a cognitive decision aiding system and new self-diagnostic abilities. The updated Longbow radar has an oversea capacity, potentially enabling naval strikes; an AESA radar is under consideration. The E model is to be fit for maritime operations. The Army has expressed a desire to add extended-range fuel tanks to the AH-64E to further increase range and endurance. AH-64Es are to have the L-3 Communications MUM-TX datalink installed in place of two previous counterparts, communicating on C, D, L, and Ku frequency bands to transmit and receive data and video with all Army UAVs. Lots 5 and 6 will be equipped with Link 16 data-links.