The US Navy is launching a competition to provide a new air-to-air radar to help the unmanned Northrop Grumman MQ-4C Triton detect other aircraft and avoid collisions.

The solicitation posed by Naval Air Systems Command (NAVAIR) on 3 November comes a year after the Navy canceled development of an Exelis-designed sense and avoid system for the MQ-4C, a high-altitude, long-endurance unmanned air system modeled on the air force’s RQ-4B Global Hawk.

The new competition is seeking a radar with less ambitious performance requirements. For example, the navy “expects” that the MQ-4C will receive data from ground radar as it approaches an airport, as air-to-air radars can be confused by ground clutter at lower altitudes.

The navy also is taking an incremental approach with the new sense and avoid radar for the MQ-4C. The radar design should be modular and scalable, the navy says, and capable of being improved as future operational and air traffic management requirements evolve.

The navy plans to filed the system with a “due regard” capability, a technological step under a full sense and avoid system, the navy says.

The navy plans to buy 70 MQ-4Cs, including five prototypes, under an $11 billion programme to monitor the vessels floating on or submerged beneath the world’s oceans and seas. It complements the manned Boeing P-8A Poseidon fleet, and together will replace the Lockheed P-3C Orion as the navy’s aerial look-out for submarines and other naval threats.