The U.S. Navy is shifting its developmental fleet of unmanned MQ-4C Tritons across the country to introduce mission systems and continue flight-testing the new maritime surveillance aircraft. The first of three Triton system development test articles (SDTA) arrived recently at Naval Air Station Patuxent River, Md.; the other two will follow by the end of October.

SDTA 1 landed at NAS Patuxent River at 7:53 a.m. on September 18 after a nearly 11-hour, 3,290-nm ferry flight from manufacturer Northrop Grumman’s Palmdale, Calif., facility. The aircraft arrived on the East Coast without mission system and airborne collision avoidance capabilities, which will come with new software iterations. The Navy is still working the technical challenge of adding a full “sense and avoid” capability the aircraft will need to fly in unrestricted airspace.

The Triton launched from restricted airspace above Edwards Air Force Base in California and landed in restricted airspace at Patuxent River. It flew an instrument route the Federal Aviation Administration approved along the southern U.S. border, the Gulf of Mexico and across Florida. Navy operators flew the aircraft at altitudes exceeding 50,000 feet along the Atlantic coast and the Chesapeake Bay to avoid conflicts with civilian air traffic. Its maximum altitude during the ferry flight was 58,000 feet.

An integrated functional capability (IFC) 2.2 software build will incorporate the Northrop Grumman multifunction active sensor radar, Raytheon MTS-B multispectral targeting system, electronic support measures and automatic identification system, said Capt. James Hoke, the Navy’s Triton program manager. Satellite-based position reporting and collision avoidance capabilities will follow when an IFC 3 software build in 2016 adds automatic dependent surveillance-broadcast (ADS-B) and traffic alert and collision avoidance system (Tcas) capabilities. These will be available when the Triton reaches initial operational capability in 2017, providing a measure of sense-and-avoid protection. The Navy’s goal is to introduce a complete solution by 2020, Hoke said during a briefing for reporters at Patuxent River.

Hoke also explained why weather delayed the Triton, which is supposed to be an all-weather platform, from making its first cross-country flight. The aircraft will make use of engine bleed air for anti-icing of the engine inlet of its Rolls-Royce AE3007H turbofan; a “thermal mechanical explosive device” system will clear ice accumulation on wing surfaces. Those systems will be activated during the IFC 3 software build. “That capability doesn’t come in until that final software build,” Hoke said. “Mechanically everything is there; we just haven’t turned it all on yet with the software. There’s also some testing that we will do once we activate those systems to make sure everything works right before we give it the flight clearance to actually fly through weather.”

In addition to two Navy and one Northrop Grumman-owned developmental test aircraft, two other Tritons are being built for initial operational test and evaluation. Hoke said the service expects to solicit a proposal soon for low-rate initial production lot 1, which will be funded in the Fiscal Year 2016 budget. The service’s Triton program of record takes attrition into account and calls for 68 total aircraft; the “steady state” will be 20 Tritons supporting five orbits of four aircraft each.