The US Air Force has awarded BAE Systems a $140 million contract related to the upgrade of 134 Lockheed Martin F-16 C/Ds operated by South Korea.

“This award is for initial development and long lead production for the program,” says the US Department of Defence (DoD). “The full program will be added in to this undefinitized contract action in fourth quarter 2014, and a modification will be done at that time to increase the scope of work to the full program.”

The initial work related to the upgrade will be undertaken in Fort Worth, Texas.

In August 2012 BAE Systems defeated Lockheed Martin in a competitive bidding process to win a contract for upgrading the avionics of Seoul’s 134 F-16s. At the time, South Korea’s Defence Acquisition Procurement Agency pegged the value of the avionics deal at $1 billion.

The avionics upgrade covers elements such as weapons, multi-function displays, and the aircraft’s mission computer.

Separately, Raytheon won a parallel competition to provide its Raytheon Advanced Combat Radar (RACR) for the fleet.

At 2013’s Seoul air show, BAE Systems said that it will initially upgrade two F-16s – one single-seat C-model aircraft and one two-seat D-model – to the new configuration. BAE will also install the new radars.

After extensive testing of the upgraded examples, BAE will then develop upgrade kits that will be shipped to South Korea, where a local company will perform the in-country upgrade work.

Upgrades of operational aircraft should begin in 2017. The US DoD says the first upgraded aircraft will be delivered in 2019.