Lockheed Martin has received a contract modification to provide system upgrades for the US Air Force (USAF) F-22 Raptor fighter fleet.

The $7.4bn contract extension was awarded under the original Raptor Enhancement Development and Integration contract secured by the company in 2002.

Under the contract, the company will provide system upgrades, added capabilities and enhanced performance for the F-22 weapon system.

The radar-evading F-22 Raptor has been frequently grounded over safety concerns relating to the aircraft’s oxygen system.

Currently, the USAF has 172 F-22 Raptors in its fleet and has plans to build a total of 187 jets.

The HQ Aeronautical Systems Center ASC/WWUK, Fighter Bomber Directorate, Wright Patterson Air Force Base, Ohio, US, will be the contracting activity.