Lockheed Martin’s [LMT] helicopter-based anti-ship missile detection system passed the U.S. Navy’s first review, the company said Sept. 5.

The Advanced Off-Board Electronic Warfare (AOEW) Active Mission payload (AMP) AN/ALQ-248 system passed a Preliminary Design Review on schedule, demonstrating sustained performance.

The Navy first awarded Lockheed Martin a $42 million AOEW contract in late 2016 as an electronic warfare system. This contract covered the system design and development phase.

The AOEW is being designed to give Sikorsky MH-60 helicopters enhanced EW surveillance and countermeasures capabilities against anti-ship missile (ASM) threats via a self-contained pod.

The AOEW can work with a ship’s onboard electronic surveillance sensor, the SEWIP Block 2 AN/SLQ-32(V)6, or independently to detect an incoming missile and evaluate where it is headed.

The system next uses radio frequency countermeasures to deter the target missile.

“Our Advanced Off-Board Electronic Warfare capabilities will give the U.S. Navy a powerful tool to detect threats and respond to our adversaries,” Joe Ottaviano, electronic warfare program director at Lockheed Martin, said in a statement.

The company said it expects to win the engineering and manufacturing development phase of the contract later in 2017, which has options for six units. If all options are exercised, the company will build up to 18 units for the Navy.

Construction of the system is planned to start in early 2018 in Syracuse, N.Y. Lockheed Martin’s Oswego, N.Y., personnel will separately integrate the AOEW onto MH-60s. The program has a 2021 initial operational capability goal.