Boeing has won a five year contract to sustain Seoul’s fleet of F-15K fighter aircraft.

The contract involves both materials and technical support, and will see Boeing use local suppliers to maintain and manufacture F-15K components, says the US airframer.

Boeing’s initial support deal was signed in 2012. The US company did not provide a value for the contract renewal.

Flight Fleets Analyzer shows that Seoul operates 59 F-15K fighter aircraft. Other fighters in the north Asian country’s fleet include 71 McDonnell Douglas F-4E Phantoms, 158 Northrop F-5Es, 118 Lockheed Martin F-16s, and 20 Korea Aerospace Industries FA-50s.

Seoul also has a firm order for 40 F-35A aircraft.