Northrop Grumman’s RQ-4A/Global Hawk was selected in May 95 after a 6-month design competition among five vendors for DARPA’s Tier II+ High Altitude Endurance (HAE) UAV Advanced Concept Technology Demonstration.
The RQ4 Global Hawk is a high-altitude, long-endurance unmanned aerial reconnaissance system designed to provide military field commanders with high-resolution, near real-time imagery of large geographic areas.
Northrop Grumman Corporation, Ryan Aeronautical Centre is the prime contractor of the Golbal hawk . The principal suppliers include Raytheon Systems (sensors), Rolls-Royce Allison (turbofan engine), Boeing North American (carbon fibre wing) and L3 Communications (communications system).
The Global Hawk air vehicles are built at the Northrop Grumman (formerly Teledyne Ryan) Aeronautical facility in San Diego.
Although the global hawk is build by Northrop Grumman at Teledyne Ryan Aeronautical center in San Diego, Raytheon developed the reconnaissance sensor suite for this high altitude endurance UAV. The suite includes a Synthetic Aperture Radar (SAR) and electro-optical (EO) and infrared (IR) sensors. Raytheon also supplies the mission control element (MCE) and launch and recovery element of the ground segment for the program.
The Global Hawk Sensor Suite is able to operate for more than 40 hours from an altitude of over 21,000 meters, day and night, in any weather. The SAR can operate simultaneously with either the EO or the IR sensor to enable coverage of wide geographic areas. This capability provides commanders with situational awareness, targeting, and bomb damage assessment.
The EO sensor incorporates a third-generation IR sensor and a Kodak digital charge coupled device (CCD) visible wavelength camera. They provide image quality that enables users to distinguish types of vehicles, aircraft, and missiles.
The sensor system makes it possible to distinguish types of vehicle, aircraft and missile and it can look through adverse weather, day or night. It can search a 40,000-square- nautical-mile area in 24 hours with three-foot resolution, or search 1,900-two-kilometre-square spots with one-foot resolution.
The SAR has three imagery collection modes: a 0.3-meter resolution spot mode, a 1-meter resolution wide area search mode, and a 4-knot minimum detectable velocity moving target indicator (MTI) mode.
The MTI mode provides the position and speed of moving targets. SAR imagery, which is processed on board the Global Hawk UAV, and EO/IR imagery are transmitted via data link in near real time, over satellite or line-of-light communication paths, to the MCE of the ground segment.
The “bulge” at the top front surface of the fuselage which gives Global Hawk its distinctive appearance, houses the 48 inch Ku-band wideband satellite communications antenna.
Global Hawk ground stations include the MCE and the LRE. The MCE is the Global Hawk’s ground control station for reconnaissance operations. It contains four workstations: mission planning, sensor data and processing, air vehicle command and control operator (CCO), and communications.
The LRE includes a mission planning function as well as air vehicle command and control. The complete MCE and the LRE is transportable in a single load on the C-5B transporter aircraft and in less than two loads on the C-17 transporter.
A differential GPS system permits precision take-off and landing to an accuracy of approx. 30 cm. The Global Hawk’s mission is to provide commanders in the field with near-real time high-resolution images.
In April 2001, Global Hawk made aviation history when it completed the first non-stop flight across the Pacific Ocean by an unmanned, powered aircraft, flying from Edwards AFB, California, to the Royal Australian Air Force Base, Edinburgh, South Australia. Global Hawk successfully participated in a series of exercises with the RAAF, the Royal Australian Navy and the US Navy.
Global Hawk can carry out reconnaissance missions in all types of operations. The 14,000 nautical mile range and 42 hour endurance of the air vehicle, combined with satellite and line-of-sight communication links to ground forces, permits world-wide operation of the system.
The first air vehicle in a new production lot of upgraded (Block 10) RQ-4A Global Hawk unmanned aerial reconnaissance vehicles made its maiden flight on July 1, 2004.
Designated AF-3, the newest Global Hawk flew from Northrop Grumman Corporation’s manufacturing facility in Palmdale, Calif., to the Flight Test Center at Edwards Air Force Base.
“The first flight of AF-3 is a significant milestone for Global Hawk because it will be the first air vehicle from Lot 2 to be delivered to the Air Force with several combat-proven upgrades integrated into the system,” said Carl O. Johnson, Northrop Grumman’s Global Hawk vice president and integrated product team leader.
AF-3 is part of Lot 2 of Global Hawk low-rate initial production and was delivered in July 2004.
In June 2006 the last RQ-4 Block 10 version was delivered to the 452nd Flight Test Squadron at Edwards Air Force Base. The aircraft will undergo a series of acceptance and operational check flights before flying to Beale Air Force Base, Calif., to take its place as a fully operational reconnaissance aircraft.
In August 2006, the Air Force announced the Global Hawk achieved 10,000 flight hours by late June, with a ratio of combat flying hours to non-combat hours increasing to 63 percent of total flight hours.
RQ-4 Block 20 (RQ-4B)
The Block 20 Global Hawk represents a significant increase in capability over the Block 10 configuration. The larger Block 20 aircraft will carry up to 3,000 pounds of internal payload and will operate with two-and-a-half times the power of its predecessor. Its open system architecture, a so-called “plug-and-play” environment, will accommodate new sensors and communication systems as they are developed to help military customers quickly evaluate and adopt new technologies.
“Our Global Hawk customers, employees and industry teammates are committed to continuously deploy increased combat capability to the fight,” said Scott Seymour, Northrop Grumman corporate vice president and president of the Integrated Systems sector. “Production Global Hawks are serving in combat with distinction today, and the addition of the Block 20 to the fleet will build upon this success and pave the way for the ever increasing capabilities currently in work for future block deliveries.”
Following a final series of systems tests and a flight test program at Edwards Air Force Base, Calif., the new Block 20 air vehicle will be delivered to the Air Force’s 9th Reconnaissance Wing at Beale Air Force Base near Sacramento, Calif.
The RQ-4B will accommodate a 50 percent increase in payload weight, and will feature a larger wingspan (130.9 feet), a longer fuselage (47.6 feet) and a new generator that can deliver 150 percent more electrical power.
The first Block 20 is the 17th Global Hawk air vehicle to be built. Northrop Grumman produced the first seven air vehicles under the advanced concept technology demonstration phase of the program. Nine Block 10 aircraft have been produced, including the two aircraft supporting the war on terrorism and two U.S. Navy aircraft operated under the Global Hawk Maritime Demonstration program.
In late May 2006, Northrop was awarded $60 million for the low rate initial production lot 6. This includes five RQ-4B vehicles, three mission control elements, three launch recovery elements and support segments/spares.