The U.S. Navy has restarted its effort to fit a “due regard” radar on the new MQ-4C Triton unmanned surveillance aircraft. The service will incorporate the radar subsystem as part of a “multi-intelligence” capability upgrade that should be initially operational on the Triton in 2020, according to Sean Burke, the Naval Air Systems Command (Navair) program manager.

Navair instructed prime contractor Northrop Grumman to stop work on the due regard radar in 2013 after subcontractor Exelis encountered problems sizing the system to the space available in the Triton’s nose. The collision avoidance radar will help the Global Hawk maritime derivative comply with an International Civil Aviation Organization requirement that military and other government aircraft fly with “due regard” for the safety of other aircraft when operating over international waters. The Triton will also be equipped with a traffic alert collision avoidance system (Tcas) and automatic dependent surveillance-broadcast (ADS-B) transmitter, but those systems alone are not considered adequate for an unmanned aircraft to “sense and avoid” other aircraft.

Speaking at the Navy League Sea-Air-Space conference on April 13, Burke said the Triton program restarted the radar subsystem development last fall. It plans to incorporate the due regard radar on a second, “multi-int” Triton configuration that adds a low-band signals intelligence (Sigint) capability now provided by the Lockheed EP-3. A baseline configuration of the Triton will enter service first, with initial operational capability (IOC) planned in 2018.

Under the new technical approach to the due regard radar, Northrop Grumman’s aerospace systems business unit in Redondo Beach, Calif., is leading the development and providing the front-end antenna array. Exelis retains responsibility for the backend processing aspect and final assembly of the antenna with the system’s power supply and receiver. Earlier this year, Harris announced that it plans to acquire Exelis for $4.75 billion, with the transaction expected to close in June.

“Technical problems in getting that radar into the size, weight and power allocations that we had available for it caused us a couple of years ago to put a pause on that and see if we could find a better technical solution,” Burke said. “Exelis had a hard time doing that miniaturization and being able to produce that front-end array.” Northrop Grumman has tasked its own business unit “to do that front end for them.”

Burke said the program expects a Milestone C decision from the Navy approving low-rate initial production (LRIP) of the Triton by the end of this year. The first two LRIP aircraft and two initial operational test and evaluation aircraft will constitute a first operational orbit. A full-rate production decision review is expected in 2018, which would phase in the multi-int capability upgrade. IOC for the multi-int configuration would follow in 2020.