The first of four French E-3F Airborne Warning and Control aircraft is being upgraded by Air France Industries, a subcontractor to U.S. aircraft maker Boeing.

The midlife upgrade, which has already begun, comes under a $354 million program, which Boeing described as the largest-ever for French AWACs aircraft.

"Air France Industries is uniquely positioned to help us provide this capability because of its substantial technical and manufacturing capabilities and over 20 years of experience with the E-3F fleet," said Steve Swanz, French AWACS program manager for Boeing. "We are also benefiting from the strong cooperation of our U.S. and French government customers."

The upgrade involves electrical, mechanical and structural systems of the aircraft and aircraft mission hardware.

Boeing is providing on-site engineering, quality assurance support, software and hardware.

The first AWACs upgrade will be completed next year. Remaining aircraft will be upgraded by 2016, Boeing said.

Boeing said the modernization is based on the U.S. AWACS Block 40/45 system and will "dramatically" enhance "reliability and effectiveness" of the aircraft and also reduce life-cycle costs.