Northrop Grumman (formerly Ryan Aeronautical) RQ-4 Global Hawk (known
as Tier II+ during development) is an unmanned aerial vehicle (UAV) used
by the United States Air Force and Navy and the German Air Force as a
In role and operational design, the Global
Hawk is similar to the Lockheed U-2, the venerable 1950s spy plane. It
is a theater commander's asset to provide a broad overview and
systematic target surveillance. For this purpose, the Global Hawk is
able to provide high resolution synthetic aperture radar (SAR) – that
can penetrate cloud-cover and sandstorms – and electro-optical/infrared
(EO/IR) imagery at long range with long loiter times over target areas.
It can survey as much as 40,000 square miles (103,600 square kilometers)
of terrain a day.
It is used as a high-altitude platform for
surveillance and security. Missions for the Global Hawk cover the
spectrum of intelligence collection capability to support forces in
worldwide military operations. According to the Air Force, the
capabilities of the aircraft allow more precise targeting of weapons and
better protection of forces through superior surveillance capabilities.
Global Hawk costs about US$35 million to procure each aircraft. With
development costs included, the unit cost rises to US$218 million.
United States Navy took delivery of two of the Block 10 aircraft to be
used to evaluate maritime surveillance capabilities, designated N-1
(BuNo 166509) and N-2 (BuNo 166510). The initial example was tested in a
naval configuration at Edwards Air Force Base for several months, later
ferrying to NAS Patuxent River on 28 March 2006 to begin the Global
Hawk Maritime Demonstration (GHMD) program. Navy squadron VX-20 was
tasked with operating the GHMD system.
The GHMD aircraft flew in
the Rim of the Pacific (RIMPAC) exercise for the first time in July
2006. Although RIMPAC operations were in the vicinity of Hawaii, the
aircraft was operated from Edwards, requiring flights of approximately
2,500 miles (4,000 km) each way to the operations area. Four flights
were performed, resulting in over 24 hours of persistent maritime
surveillance coordinated with USS Abraham Lincoln and USS Bonhomme
Richard. As a part of the demonstration program, Global Hawk was tasked
with maintenance of maritime situational awareness, contact tracking,
and imagery support of various exercise operations. The imagery obtained
by Global Hawk was transmitted to NAS Patuxent River for processing
before being forwarded on to the fleet operations off Hawaii, thus
exercising the global nature of this aircraft's operations.
Grumman entered a version of the RQ-4B in the US Navy's Broad Area
Maritime Surveillance (BAMS) UAV contract competition. On 22 April 2008
the announcement was made that the Northrop Grumman RQ-4N had won the
bid, with the Navy awarding a contract worth US$1.16 billion. In
September 2010, the RQ-4N was officially designated the MQ-4C.
11 June 2012 a U.S. Navy RQ-4A Global Hawk crashed near Salisbury,
Maryland, during a training flight from Naval Air Station Patuxent
development cost overruns had put the Global Hawk system at risk of
cancellation. Per-unit costs in mid-2006 were 25% over baseline
estimates, caused by both the need to correct design deficiencies as
well as increase the system's capabilities. This caused some concerns
about a possible congressional termination of the program if its
national security benefits could not be justified. However, in June
2006, the Global Hawk program was restructured. Completion of an
operational assessment report by the Air Force was delayed from August
2005 to November 2007 due to manufacturing and development delays. The
operational assessment report was released in March 2007 and production
of the 54 air vehicles planned has been extended by two years to 2015.
In February 2011, the Air Force reduced its planned buy of RQ-4 Block 40 aircraft from 22 to 11 in a cost-cutting move.
U.S. Defense Department's Director, Operational Test and Evaluation
(DOT&E) found the RQ-4B "not operationally effective" for its
mission due to aircraft reliability issues in June 2011.
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 that: "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 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
On 26 January 2012, the Pentagon announced plans to
end Global Hawk Block 30 procurement as the Block 30 was found to be
more expensive to operate than the U-2, and its sensor suite was not as
capable as the manned aircraft. Plans to increase the procurement of the
Block 40 variant were also announced.
December 2007, two Global Hawks were transferred from the U.S. Air
Force to NASA's Dryden Flight Research Center at Edwards Air Force Base.
Initial research activities beginning in the second quarter of 2009
supported NASA's high-altitude, long-duration Earth science missions.
The three Global Hawks were the first, sixth and seventh aircraft built
under the original DARPA Advanced Concept Technology Demonstration
program, and were made available to NASA when the Air Force had no
further need for them. Northrop Grumman is an operational partner with
NASA and will use the aircraft to demonstrate new technologies and to
develop new markets for the aircraft, including possible civilian uses.
to an article in the March 2010 issue of Scientific American (p.
25-27), the Global Hawk aircraft belonging to NASA were in use for
testing purposes as of October 2009, with science missions expected to
start in March 2010. Initial science applications included measurements
of the ozone layer and cross-Pacific transport of air pollutants and
aerosols. The author of the Scientific American piece speculates that
the aircraft could be used for Antarctic exploration while based in and
operated from Chile.
In August and September 2010 one of the two
Global Hawks was loaned for NASA's GRIP Mission (Genesis and Rapid
Intensification Program), with its long-term on station capabilities and
long range it was the best aircraft for the mission to monitor the
development of Atlantic basin Hurricanes. It was modified to equip
weather sensors including Ku-Band Radar, Lightning sensors and
Dropsondes. It successfully flew into Hurricane Earl off the United
States East Coast on September 2.
German Air Force (Luftwaffe) is the aerial warfare branch of the German
Armed Forces. The term "Luftwaffe" is the name of both the former World
War II-era Wehrmacht Luftwaffe and the post-World War II Bundeswehr
Luftwaffe air forces.
The German Empire's World War I-era army
air force, the Luftstreitkräfte, and naval air units were disbanded
under the term of the Treaty of Versailles. After the defeat of the
Third Reich the Luftwaffe was disbanded in 1946. A new Bundeswehr
Luftwaffe was founded in 1956 and remains as the German air force to the
Luftwaffe is also the usual generic term in German
speaking countries for any national military aviation service, and the
names of air forces in other countries are usually translated into
German as "Luftwaffe" (e.g. Royal Air Force is often translated as
britische Luftwaffe). However, Luftstreitkräfte, or "air armed force",
is also sometimes used as a translation of "air force", as first used in
October 1916 for the German Empire's own Army-attched air service. And
because Luft means "air" and Waffe may be translated into English as
either "weapon" or "arm", "Air Arm" may be considered the most literal
English translation of Luftwaffe (cf. Fleet Air Arm).
first seven aircraft were built under the Advanced Concept Technology
Demonstration (ACTD) program, sponsored by DARPA, in order to evaluate
the design and its capabilities. Due to world circumstances, the
capabilities of the aircraft were in high demand, so the prototype
aircraft were operated by the U.S. Air Force 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 configuration) were
produced, two of which were sold to the US Navy. Two more were sent to
Iraq to support operations there. The final Block 10 aircraft was
delivered on June 26, 2006.
In order to increase the aircraft's
capabilities, the airframe was redesigned, with the nose section and
wings being stretched. The changes, with the designation RQ-4B Block 20,
allow the aircraft to carry up to 3,000 pounds 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 August 25,
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. Future Block 30
and 40 aircraft, similar in size to the Block 20, are scheduled for
development from 2008 to 2010. When the Global Hawk was produced it was
in a sale plan for more than 5 countries including USA and Germany.
RQ-4 is powered by an Allison Rolls-Royce AE3007H turbofan engine with
7,050 lbf (31.4 kN) thrust, and carries a payload of 2,000 pounds (900
kilograms). The main fuselage is standard aluminum, semi-monocoque
construction, while the wings are made of lightweight, high-strength
Global Hawk UAV system comprises an air vehicle segment consisting of
air vehicles with sensor payloads, avionics, and data links; a ground
segment consisting of a Launch and Recovery Element (LRE), and a Mission
Control Element (MCE) with embedded ground communications equipment; a
support element; and trained personnel.
The Integrated Sensor
Suite (ISS) is provided by Raytheon and consists of a synthetic aperture
radar (SAR), electro-optical (EO), and infrared (IR) sensors. Either
the EO or the IR sensors can operate simultaneously with the SAR. Each
of the sensors provides wide area search imagery and a high-resolution
spot mode. The SAR has a ground moving target indicator (GMTI) mode,
which can provide a text message providing the moving target's position
and velocity. Both SAR and EO/IR imagery are processed on board the
aircraft and transmitted to the MCE as individual frames. The MCE can
mosaic these frames into images prior to further dissemination.
is via inertial navigation with integrated Global Positioning System
updates. Global Hawk is intended to operate autonomously and
"untethered" using a satellite data link (either Ku or UHF) for sending
sensor data from the aircraft to the MCE. The common data link can also
be used for direct down link of imagery when the UAV is operating within
line-of-sight of users with compatible ground stations.
ground segment consists of a Mission Control Element (MCE) and Launch
and Recovery Element (LRE), provided by Raytheon. The MCE is used for
mission planning, command and control, and image processing and
dissemination; an LRE for controlling launch and recovery; and
associated ground support equipment. (The LRE provides precision
differential global positioning system corrections for navigational
accuracy during takeoff and landings, while precision coded GPS
supplemented with an inertial navigation system is used during mission
execution.) By having separable elements in the ground segment, the MCE
and the LRE can operate in geographically separate locations, and the
MCE can be deployed with the supported command's primary exploitation
site. Both ground segments are contained in military shelters with
external antennas for line-of-sight and satellite communications with
the air vehicles.
German Air Force (Luftwaffe) has ordered a variant of the RQ-4B
equipped with German sensors, dubbed EuroHawk. It combines a normal
RQ-4B airframe with an EADS reconnaissance payload.
is based on the Block 20/30/40 RQ-4B, but will be equipped with EADS'
SIGINT package to fulfil Germany's desire to replace their aging
Dassault-Breguet Atlantique electronic surveillance aircraft. That
sensor package comes in the form of six wing mounted pods, a first for
the Global Hawk. The EuroHawk was officially rolled out on October 8,
2009 and first flight took place on June 29, 2010. It underwent several
months of flight testing at Edwards Air Force Base before flying to
Germany. On July 21, 2011, the first EuroHawk arrived in Manching,
Germany where it will be equipped with the SIGINT sensor package. There
it is also slated to undergo more testing and pilot training, until the
first quarter of 2012, when it will be officially handed over to the
Luftwaffe to be stationed with the Reconnaissance Wing 51. The costs
for the initial five aircraft are approx. €430 million for the
development, and €430 million for the actual procurement.