Northrop Grumman Corp. on Tuesday said that it won an U.S. Air Force contract valued at nearly $224 million to provide components for surveillance aircraft.

The Los Angeles defense contractor will deliver two E-8C joint surveillance airborne systems that are designed to detect, track and target hostile ground movements. Each system includes four Pratt & Whitney aircraft engines.

Deliveries are expected to start in 2011. The aircraft will eventually be used by the Georgia Air National Guard’s 116th Air Control Wing based at Robins Air Force Base.

Northrop Grumman closed down 15 cents, or less than 1 percent, to $62.86 on the New York Stock Exchange.