Unlike the heavily adapted Block 10 BAMS-Ds, the larger-span, heavier MQ-4C is purpose-designed to provide persistent maritime intelligence, surveillance and reconnaissance (ISR) at a mission radius of 2,000 nm for 24 hr. seven days per week with 80% effective time-on-station. The Triton is externally distinguished from all previous Global Hawk variants by the bulbous belly housing of its 360-deg. multifunction active sensor active, electronically steered array (MFAS AESA) X-band radar, as well as a titanium engine inlet cowl incorporating an anti-ice/deice system. The wing leading edges are also configured with a deicing system and treated to improve resistance to hail and bird-strike.
Internally, the wing is strengthened to withstand gust loads that will be encountered on sea patrol, while the forward fuselage is also beefed up to house the MFAS and other sensors. A fixed chin fairing is positioned under the chin for the Raytheon-supplied auto-target tracking electro-optic/infrared turret system. The multispectral system includes full-motion video and can zoom in to visually identify ships using its high-resolution optics.
The MFAS, in development flight tests on a Northrop Grumman Gulfstream II testbed, is designed for maritime detection, tracking and classification using maritime search, inverse synthetic aperture (ISAR) and SAR modes. MFAS test flights are “scheduled through October as the program matures,” says Capt. James Hoke, program manager for the Persistent Maritime Unmanned Aircraft Systems Program Office (PMA-262). “Thirty testbed aircraft flights for early MFAS trials are planned. The tests will focus on maturing the performance of maritime surface surveillance modes of the radar,” he adds.
The MFAS is the “highest-risk sensor,” says Hoke. Flight tests in the Gulfstream “allow us to learn a lot about what the needs of the P-3 community are that will operate it. This tells us everything from what that community expects to what sort of data will be shared,” he adds, referring to the UAS's role as part of a broader set of systems.
Unlike its land-bound predecessors, the MQ-4C will also carry the Automatic Identification System (AIS), which provides information received from VHF broadcasts on maritime vessel movements around the world. It incorporates an AN/ZLQ-1 electronic support measures system as well, and a “due-regard,” nose-mounted radar forward of the large wideband satcom antenna for safe separation.
Developed by ITT Excelis, the due-regard system, also known as the Air-to-Air Radar Sub-System is a three-panel AESA designed to provide a sense-and-avoid capability for the MQ-4C. The radar is “post-critical design review and is currently performing component-level integration and test,” says Hoke.
Following a series of up to nine test flights in the Edwards AFB restricted airspace, the first system demonstrator aircraft (SDD 1) will transit to Patuxent River to complete development work. “SDD 2 will be about a month behind it,” says Hoke. “Our goal is to fly SDD 1 will all sensors on its first flight.” In all, the Navy plans to acquire 68 MQ-4Cs to maintain a standing operational fleet of 22 aircraft.
Although no firm decisions have been announced, the MQ-4Cs are expected to be based at sites in Hawaii, Diego Garcia, Japan, Italy and at NAS Jacksonville, Fla., and NAS Point Mugu, Calif.