The US Department of Defense (DoD) has approved a plan to develop the Northrop Grumman RQ-4A Global Hawk's capability in phases, or spirals. It has directed the USAir Force to support US Navy proposals to use the long-endurance unmanned air vehicle for its Broad Area Maritime Surveillance programme.

Spiral 1 will "operationalise" the Global Hawk technology demonstrator, improve communications, speed mission planning and address obsolescence issues. It will be introduced late next year with delivery of the first production aircraft. Spiral 2 will improve air vehicle performance by increasing gross weight, endurance, electrical power and payload and includes a new wing.

Sensor range will be increased and an initial, quick-reaction, low-band signals intelligence (SIGINT) capability added. Last month Northrop Grumman received contracts totalling $300 million to develop Spiral 2 capabilities to be phased in from early 2004 with the third production Global Hawk.

Spiral 2 is the baseline for the naval Global Hawk. The USN is negotiating with the USAF to acquire two air vehicles from the second production batch for a demonstration and experimentation phase running in 2005-8 to define the sensor payload and maritime concept of operations. The baseline includes maritime modes for the Raytheon electro-optical/infrared and synthetic aperture radar sensors and an electronic support measures payload.

Spiral 3 capabilities will be phased in from late 2004 with the seventh aircraft. They include an initial self-protection suite, simultaneous sensor image recording, satellite communications via Inmarsat and high-band SIGINT and will pave the way for integration of an active electronically scanned array (AESA) radar during Spiral 4. The next-generation sensor is being developed by Northrop Grumman and Raytheon.

Spiral 4 capabilities, designed to improve reliability and survivability, will be phased in beginning with the 17th aircraft in late 2006. The AESA will be introduced with the 33rd Global Hawk in 2009.

The DoD has approved low-rate initial production of 17 air vehicles for the USAF, starting with two in fiscal year 2003, four each in FY04 and FY05 and rising to six in FY06.

The USAF plans to increase Global Hawk operational flexibility with Spiral 5 and 6 capabilities to begin during full-rate production.

Source: Flight International