The Northrop Grumman RQ-4 Global Hawk is a high-altitude, remotely-piloted surveillance aircraft introduced in 2001. It was initially designed by Ryan Aeronautical (now part of Northrop Grumman), and known as Tier II+ during development. The RQ-4 provides a broad overview and systematic surveillance using high-resolution synthetic aperture radar (SAR) and electro-optical/infrared (EO/IR) sensors with long loiter times over target areas.
The Global Hawk is operated by the United States Air Force (USAF). It is used as a high-altitude long endurance (HALE) platform covering the spectrum of intelligence collection capability to support forces in worldwide military operations. According to the USAF, the superior surveillance capabilities of the aircraft allow more precise weapons targeting and better protection of friendly forces.
Cost overruns led to the original plan to acquire 63 aircraft being cut to 45, and to a 2013 proposal to mothball the 21 Block 30 signals intelligence variants. The initial flyaway cost of each of the first 10 aircraft was US$10 million in 1994. By 2001, this had risen to US$60.9 million (~$ in ),"Soaring Costs Not Likely to Slow Down Global Hawk". National Defence Magazine, May 2006. and then to $131.4 million (flyaway cost) in 2013. The U.S. Navy has developed the Global Hawk into the MQ-4C Triton maritime surveillance platform. , the U.S. Air Force plans to retire its Global Hawks in 2027.
Development Origins
In the 1990s, the Air Force was developing uncrewed aerial intelligence platforms. One was the stealthy Lockheed Martin RQ-3 DarkStar; another was the Global Hawk. Due to budget cuts, only one of the programs could survive. It was decided to proceed with the Global Hawk for its range and payload rather than go with the stealth Dark Star.
The Global Hawk took its first flight on 28 February 1998, at Edwards Air Force Base, California.Guinness World Records 2000: Millennium Edition, The first seven aircraft were built under the Advanced Concept Technology Demonstration (ACTD) program, sponsored by DARPA, in order to evaluate the design and demonstrate its capabilities. Demand for the RQ-4's abilities was high in the Middle East; thus, the prototype aircraft were actively operated by the USAF in the War in Afghanistan. In an unusual move, the aircraft entered initial low-rate production while still in engineering and manufacturing development. Nine production Block 10 aircraft, sometimes referred to as RQ-4A, were produced; of these, two were sold to the US Navy and an additional two were deployed to Iraq to support operations there. The final Block 10 aircraft was delivered on 26 June 2006."Last Block 10 Global Hawk Arrives For Check Flights". spacewar.com
To increase the aircraft's capabilities, the airframe was redesigned, with the nose section and wings being stretched. The modified aircraft, designated RQ-4B Block 20, can carry up to 3,000 lb (1,360 kg) of internal payload. These changes were introduced with the first Block 20 aircraft, the 17th Global Hawk produced, which was rolled out in a ceremony on 25 August 2006."Northrop unveils next generation Global Hawk", Aerotech News and Review, 1 September 2006. First flight of the Block 20 from the USAF Plant 42 in Palmdale, California, to Edwards Air Force Base took place on 1 March 2007. Developmental testing of Block 20 took place in 2008.McGee, Chris, "Global Hawk in demand, passes 10,000 flight hours milestone", Aerotech News and Review, 11 August 2006.
United States Navy version
The United States Navy took delivery of two of the Block 10 aircraft to evaluate their maritime surveillance capabilities, designated N-1 (BuNo 166509) and N-2 (BuNo 166510).Northrop Grumman Press Release , 13 June 2005. The initial navalised example was tested at Edwards Air Force Base briefly, before moving to Naval Air Station Patuxent River in March 2006 for the Global Hawk Maritime Demonstration (GHMD) program, operated by Navy squadron VX-20.Selinger, M. "U.S. Navy To Receive First Global Hawk Next Week ." Aviation Week & Space Technology. 1 October 2004.
In July 2006, the GHMD aircraft flew in the Rim of the Pacific (RIMPAC exercise) for the first time. Although it was in the vicinity of Hawaii, the aircraft was operated from NBVC Point Mugu, requiring flights of approximately each way to the area. Four flights were performed, resulting in over 24 hours of persistent maritime surveillance coordinated with the aircraft carrier and amphibious warfare ship . For the GHMD program, the Global Hawk was tasked with maintaining maritime situational awareness, contact tracking, and imagery support of exercise operations. Images were transmitted to NAS Patuxent River for processing and then forwarded to the fleet off Hawaii."Navy Global Hawk Performs in RIMPAC", Aerotech News and Review, 18 August 2006.
Northrop Grumman entered an RQ-4B variant in the US Navy's Broad Area Maritime Surveillance (BAMS) UAV competition. On 22 April 2008, it was announced that Northrop Grumman's RQ-4N had won and that the Navy had awarded a US$1.16 billion (~$ in ) contract. In September 2010, the RQ-4N was officially designated the MQ-4C.
The Navy MQ-4C differs from the Air Force RQ-4 mainly in its wing. While the Global Hawk remains at high altitude to conduct surveillance, the Triton climbs to to see a wide area and can drop to to get further identification of a target. The Triton's wings are specially designed to take the stresses of rapidly decreasing altitude. Though similar in appearance to the Global Hawk's wings, the Triton's internal wing structure is much stronger and has additional features including anti-icing capabilities and impact and lightning strike protection.Triton Testing Ahead of Schedule – News.USNI.org, 21 February 2014
On 17 June 2022, the Navy brought its last deployed RQ-4A BAMS-D back from the Middle East, ending what started as a six-month experiment but turned into a 13-year deployment. The Navy had acquired five Block 10 RQ-4As and since 2009 at least one had been kept on rotation in the Persian Gulf region. The aircraft accrued over 42,500 flight hours in 2,069 missions; one was lost in an accident and another was shot down by Iran. The BAMS-D was replaced in Navy service with the MQ-4C.
Cost increases and procurement Development cost overruns placed the Global Hawk at risk of cancellation. In mid-2006, per-unit costs were 25% over baseline estimates, caused by both the need to correct design deficiencies as well as to increase its capabilities. This caused concern over a possible congressional termination of the program if its national security benefits could not be justified. However, in June 2006, the program was restructured. Completion of an operational assessment report by the USAF was delayed from 2005 to 2007 due to manufacturing and development delays. The operational assessment report was released in March 2007 and production of the 54 air vehicles planned was extended by two years to 2015.
In February 2011, the USAF reduced its planned purchase of RQ-4 Block 40 aircraft from 22 to 11 in order to cut costs.Putrich, Gayle. "Northrop: Global Hawk not slowing down even with cuts". Flight International, 22 February 2011. In June 2011, the U.S. Defense Department's Director, Operational Test and Evaluation (DOT&E), found the RQ-4B "not operationally effective" due to reliability issues."Pentagon Says Northrop Drone Isn’t ‘Effective’." Bloomberg News, 6 June 2011. In June 2011, the Global Hawk was certified by the Secretary of Defense as critical to national security following a breach of the Nunn-McCurdy Amendment; the Secretary stated: "The Global Hawk is essential to national security; there are no alternatives to Global Hawk which provide acceptable capability at less cost; Global Hawk costs $220M less per year than the Lockheed U-2 to operate on a comparable mission; the U-2 cannot simultaneously carry the same sensors as the Global Hawk; and if funding must be reduced, Global Hawk has a higher priority over other programs.""Nunn-McCurdy Certification Acquisition Decision Memorandum for the Restructured RQ-4A/B Unmanned Aircraft System Global Hawk." Memorandum for Secretary of the Air Force, 14 June 2011.
On 26 January 2012, the Pentagon announced plans to end Global Hawk Block 30 procurement as the type was found to be more expensive to operate and with less capable sensors than the existing U-2."Defense Budget Priorities and Choices", p. 11 . US DoD, January 2012.Clark, Colin. "Air Force To Cut 10,000; Global Hawks Get Warehoused." Aol Defense, 27 January 2012. Plans to increase procurement of the Block 40 variant were also announced."USAF Cancels Block 30 RQ-4 Global Hawk". Defense Update, 29 January 2012. The Air Force's fiscal year 2013 budget request said it had resolved to divest itself of the Block 30 variant; however, the National Defense Authorization Act for Fiscal Year 2013 mandated operations of the Block 30 fleet through the end of 2014. The USAF plans to procure 45 RQ-4B Global Hawks as of 2013. Before retiring in 2014, ACC commander, General Mike Hostage said of the U-2's replacement by the drone that "The combatant commanders are going to suffer for eight years and the best they're going to get is 90 percent".
During 2010–2013, costs of flying the RQ-4 fell by more than 50%. In 2010, the cost per flight hour was $40,600, with contractor logistic support making up $25,000 per flight hour of this figure. By mid-2013, cost per flight hour dropped to $18,900, contractor logistic support having dropped to $11,000 per flight hour. This was in part due to higher usage, spreading logistics and support costs over a higher number of flight hours."Cost of flying Northrop’s Global Hawk down over 50%" – suasnews.com, 14 September 2013 In 2015, the RQ-4 was planned to replace the U-2 by 2019, though Lockheed Martin stated the U-2 can remain viable until 2050.Drew, James. "U-2 poised to receive radar upgrade, but not un-manned conversion." Flightglobal.com, 31 July 2015. Retrieved: 7 December 2015. As of January 2018, the U.S. Air Force budget for 2018 had indefinitely postponed the retirement of the U-2.Insinna, Vallerie. "With U-2 safe, operators vie for greater investment". Defense News, Vol. 33 No. 1 (p. 13), 8 January 2018. In February 2020, the U.S. Air Force submitted budget documents with confusing language suggesting that it could begin retiring U-2s in 2025 but clarified afterwards that no retirement is planned.Cohen, Rachel S. "Budget Elicits Confusion Over Fate of U-2". Airforce Magazine, 11 February 2020.
In July 2022, the US Air Force announced plans to retire the Global Hawk in 2027."Air Force’s RQ-4 Global Hawk drones headed for the boneyard in FY27". Breaking Defense, retrieved 27 July 2022.
EuroHawk
The German Air Force (Luftwaffe) ordered a variant of the RQ-4B, to be equipped with a customized sensor suite, designated "EuroHawk". The aircraft was based on the RQ-4B Block 20/30/40 and was to be equipped with an EADS-built signals intelligence (SIGINT) package; it was intended to fulfill Germany's requirement to replace their aging Dassault-Breguet Atlantique electronic surveillance aircraft of the Marineflieger (Naval Air arm of the German Navy). The EADS sensor package is composed of six wing-mounted pods; reportedly these sensor pods could potentially be used on other platforms, including crewed aircraft.