Maritime patrol is a mission as old as the naval service, but with the advent of the unmanned MQ-4C Triton, the seagoing version of the Global Hawk, the U.S. Navy plans to elevate this definition to an entirely new level.

The move to unmanned air systems (UAS) for the yeoman's work of long-range surveillance is part of a two-pronged transformational strategy that includes replacing aging P-3 patrol aircraft with the Boeing P-8A. However, as the apparently still unexplained crash of a maritime Global Hawk demonstrator just three days before the June 14 Triton roll-out shows, the transition remains more challenging than the basic development of a new concept of operations.

The Navy appeared determined not to let the loss of the Broad Area Maritime Surveillance Block 10 demonstrator (BAMS-D) overshadow the unveiling of the first MQ-4C at Northrop Grumman's facility in Palmdale, Calif. Officials note that the lost demonstrator, one of five modified ex-U.S. Air Force RQ-4 vehicles paving the way for the MQ-4C, is radically different from the gray-and-white-painted aircraft now being readied for its first flight.

The 116-ft.-wingspan demonstrator crashed in unpopulated wetlands June 11 near Bloodsworth Island in Dorchester County, Md., 22 mi. east of its base at NAS Patuxent River. Although declining to comment on the progress of the investigation, the Navy is confident it will gain a clear picture of what happened. “It will take weeks to sort it out, but one of the good things with UAVs is all the information on the health and state of the vehicle it collected,” says Rear Adm. Bill Shannon, unmanned aviation and strike weapons program executive officer.

Shannon adds that the accident took place 10 min. after takeoff while the RQ-4 was still orbiting in a climbing spiral within restricted airspace, enroute to its operating altitude of 50,000 ft. Images of the crash site appear to show that the RQ-4 impacted in a relatively flat attitude, having evidently descended in a slow spiral.

The investigation is assessing the mishap against causes of previous Global Hawk losses. Those ranged from inadvertent radio transmission on the aircraft's flight termination frequency to incorrectly installed hardware and a faulty fuel nozzle valve.

Meanwhile, preparations continue for first flight of the initial MQ-4C by the end of 2012, says Northrop Grumman. For the Navy, flight testing and build-up to initial operational capability in 2015 cannot come soon enough. “This capability has never been needed more as we rebalance toward the Pacific,” says Vice Chief of Naval Operations Adm. Mark Ferguson. Describing the UAS as a force multiplier, Ferguson says, “BAMS will provide an asymmetric advantage to the U.S. Navy. Long-range persistent surveillance transforms the nature of warfare at sea.”

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.

MQ-4C Triton (BAMS UAS) Specifications
Length 47.6 ft.
Height 15.3  ft.
Wingspan 130.9 ft.
Takeoff weight 32,250 lb.
Airspeed 310 kt/357 mph
Endurance 30 hr.
Ceiling 60,000 ft.
Engine Rolls-Royce AE3007H
Range 9,950 nm
Contract cost $1.6 billion
Source: U.S. Navy