The US Navy is upgrading its Boeing F/A-18E/F fighters with an improved Lockheed Martin IRST21 sensor system, allowing the Super Hornet fleet to see and detect farther.

Lockheed received two contracts worth $100 million through prime contractor Boeing and will provide advanced software development, hardware upgrades and prototype deliveries as part of the Block 2 IRST package.

An older version of IRST, a passive air-to-air radar system that detects airborne threats in radar denied environments, exists on the US Navy’s Boeing F/A-18E/F fleet and international F-15 aircraft. While some international customers mount their IRST systems on top of an aircraft, the US Navy install their long-range, thermal sensor inside the Super Hornet’s centerline fuel tank.

“It’s really a configuration of the aircraft itself, it can be mounted anywhere on the aircraft there’s no real rationale as to performance where you put it on the aircraft,” David Starr, senior programme manager at Lockheed, tells FlightGlobal.

The improved Block 2 sensor maintains the same fuel tank but delivers extended range and better targeting capability with upgraded internal systems, such as the receiver and the processor, Starr says. The navy’s long term plan is to field 170 Block 2 sensors across its Super Hornet fleet.

The Block 2 upgrades are part of the navy’s ongoing IRST programme. As part of the technical development phase, Lockheed will deliver low rate initial production lots 1 and 2 to the service in 2019. Those lots will be used for testing, training and tactics development, and include 18 legacy sensors embedded in fuel tanks Starr says. In 2022, Lockheed will deliver Block 2 engineering, development and manufacturing assets.

“Block 1...could be fielded, right now they’re explicitly for test,” he says. “But right now the navy is debating whether they would like to field those going forward in the future.”