Northrop Grumman Corp. was awarded a $1.2 billion, 20-year contract Thursday to provide aircraft maintenance and design support services to England’s Royal Air Force.

The contract is fully funded for the next 20 years, when the fleet is expected to go out of service. The price is fixed for the first five years.

The agreement includes supply chain management and overseeing the modernization of England’s fleet of E-3D Sentry Airborne Warning and Control System (AWACS) aircraft. Northrop will work with AAR Corp. of Wood Dale, Ill., along with BAE Systems PLC and FR Aviation in England.

Nearly 165 people are slated to work on the project, with 145 of them in the UK. Work will be performed at the Royal Air Force base in Waddington, Lincolnshire. Four Northrop operating units have been integrated to work on the planes, with its IT division leading the program.

The aircraft provide strategic support to Britain’s armed forces around the world.