Alliant Techsystems says it’s landed its largest commercial contract ever and will make Airbus airplane parts in a deal worth about $1 billion.

The Eden Prairie military and space supplier will make parts for the new AirbusA350 airplanes at a plant in Iuka, Miss.

Airbus says the A350 planes are lighter than regular aircraft because the fuselage and wing structures are made primarily of carbon fiber. The lighter planes burn less fuel, the largest expense for airlines.

Airbus expects to deliver the first A350 in 2013.