On Thursday, Sparton Corporation (NYSE: SPA) announced that its ERAPSCO joint venture with Britain's Ultra Electronics Holdings has won a $17.9 million contract to produce sonobuoys for the U.S. Navy.

The sonobuoys in question are designated AN/SSQ-125 MAC Source Sonobuoys, and are used in anti-submarine warfare -- dropped by sub-hunting planes, such as Boeing's (NYSE:BA) P-8 Poseidon, or Lockheed Martin's (NYSE:LMT) P-3 Orion in the vicinity of enemy subs, to help localize their targets. They are expendable (meaning they need to be replaced as they are used), and use multistatic active coherent sonar to detect targets.

Delivery of the sonobuoys is scheduled for March 2015.