In mid-2016 South Korea received the first of eight of its older P-3s that had been upgraded to the current P-3C standard. This upgrade was ordered in 2013 and that led to disagreements with the United States over what type of tech could be used for the upgrade. The United States was reluctant to allow the export of a key electronic warfare components for new weapons or upgrades. This was especially true with gear that detects and classifies radar signals or interprets acoustic signals from sonar. The U.S. believed that these items (or parts of them) might be stolen (by China and a number of other usual suspects) and thus degrade the effectiveness of the technology for the United States. For example, P-3Cs operated by the U.S. Navy and some of the most trusted allies use the AN/USQ-78B acoustic processor system. South Korea was forced to use a non-military one that is largely open source software (Vpx ENhanced Open architecture, Multi-static, or VENOM). Many other P-3 operators who cannot get the AN/USQ-78B use VENOM instead. According to users, the P-3Cs with VENOM seem as effective as those with the AN/USQ-78B. South Korea also used local electronics firms to improve their version of VENOM. Now South Korea, long an electronics powerhouse, can sell that to other P-3C users.
This dispute actually began in 2010 when South Korea finally received the eight American P-3C maritime reconnaissance aircraft it had ordered. It wasn’t long before South Korea sought to upgrade their P-3Cs m to the latest standard because of unexpected North Korean aggression. Despite the need South Korea ran into an 18 month delay because the U.S. refused to upgrade the South Korea P-3Cs with the AN/USQ-78B. This caused a problem with South Korea, which did not like being excluded from the “most trusted” club. The South Koreans eventually accepted the U.S. fears (there are a lot of Chinese, Russian and North Korean spies operating in South Korea) and went for alternatives like VENOM. South Korea has 24 P-3s in service, eight of them P-3Cs and ten of the older P-3As being upgraded to the P-3C standard using VENOM systems.
South Korea is eager to obtain more, and better, anti-submarine capabilities. North Korea has a growing fleet of small coastal subs that are a real threat to South Korean warships. To prove the point, a North Korean sub sank a South Korean corvette in 2010. The upgraded P-3Cs are part of the solution. Despite the cutting edge electronics, the American built P-3C airframe is getting old. The average age of the U.S. P-3Cs is 28 years. The P-3 entered service in 1962. The current version has a cruise speed of 610 kilometers per hour, endurance of up to 13 hours, and a crew of eleven. The 37.4 meter (116 foot) long, propeller driven aircraft has a wingspan of 30 meters (nearly 100 feet). The P-3C can carry about ten tons of weapons (torpedoes, mines, or missiles like Harpoon and Maverick). In the event of a war in Korea, the P-3s would be essential for patrolling coastal waters and even land areas. In the meantime, South Korea wants more P-3s to keep track of the growing number of North Korean and Chinese subs in the area.