Airborne Intelligence, Surveillance & Reconnaissance (ISR): The U-2 Aircraft and Global Hawk UAV Programs

CRS Report for Congress
Airborne Intelligence, Surveillance &
Reconnaissance (ISR): The U-2 Aircraft and
Global Hawk UAV Programs
Updated December 1, 2000
Richard A. Best, Jr.
Specialist in National Defense
Christopher Bolkcom
Analyst in National Defense
Foreign Affairs, Defense, and Trade Division

Congressional Research Service The Library of Congress

The U-2 Aircraft Program
The ability to gather accurate and timely information on enemy forces is an
essential enabler of modern military operations. The growing use of precision guided
munitions (PGMs) which can destroy specific targets without extensive collateral
damage depends upon the availability of precise information. No single platform or
technology can satisfy the needs of the Department of Defense (DoD) for information
at all times in all scenarios. However, airborne platforms will likely continue to satisfy
a large portion of DoD’s ISR requirements over the next several decades.
Among airborne ISR platforms, the U-2 Dragon Lady and the RQ-4A Global
Hawk are especially valuable. The U-2 stands out for its proven track record of
providing vital near-real-time intelligence to military theater commanders in the 1991
war with Iraq (Operation Desert Storm), the 1999 conflict in Kosovo (Operation
Allied Force), and other conflict areas.
Global Hawk, a soon to be fielded unmanned aerial vehicle (UAV), has been
considered a complement to, and potentially a replacement for the U-2. While the un-
proven Global Hawk appears to offer some advantages over the U-2 – such as greater
range and endurance, and not exposing a pilot to danger – as currently designed it
does not currently match the U-2's intelligence gathering capabilities. The Air Force
is seeking to upgrade these designs so the second generation of Global Hawks would
be more similar to U-2s in capability.
Both Congress and DoD face important decisions regarding current and future
mix of U.S. airborne intelligence, surveillance, and reconnaissance capabilities. An
overarching line of inquiry is: Over the next 20 to 30 years, what mix of existing and
planned manned and unmanned ISR aircraft can most effectively satisfy DoD’s
requirement for timely and accurate information on enemy forces?
An important immediate issue to be resolved is how to best introduce Global
Hawk platforms into the U.S. ISR inventory and at what pace, relative to planned or
unplanned U-2 attrition. Key concerns are whether manned aircraft can be completely
replaced by UAVs, the time that it will take to integrate the Global Hawks into the
operating force structure, and the availability of adequate funds to support the
acquisition of Global Hawks without compromising vital operational capabilities for
an extended period.

Background .................................................... 1
Intelligence, Surveillance and Reconnaissance (ISR).................1
U-2 Dragon Lady...........................................3
U-2s in Post-Cold War Combat Operations....................6
RQ-4A Global Hawk.........................................8
Summary: Platform Comparisons...............................9
Congressional Action............................................11
Overview ................................................. 11
DoD Budget FY 2001.......................................12
Intelligence Budget FY 2001..................................14
Issues and Options..............................................15
Conclusion ................................................... 19
Appendix 1: Abbreviations and Acronyms............................20
List of Figures
Figure 1. U-2 Dragon Lady........................................4
Figure 2. RQ-4A Global Hawk.....................................8
List of Tables
Table 1. USAF Reconnaissance & Surveillance Aircraft
Active Inventory (May 2000)...................................3
Table 2. Comparison of Key Characteristics...........................11
Table 3: Summary of U-2 & Global Hawk Funding FY2001..............13

Airborne Intelligence, Surveillance &
Reconnaissance (ISR): The U-2 Aircraft and
Global Hawk UAV Programs
Intelligence, Surveillance and Reconnaissance (ISR)
The ability to gather accurate and timely information on enemy forces is an
essential enabler of modern military operations. Joint Vision 2010, the Pentagon’s
“conceptual achieve new levels of effectiveness in joint warfighting”
specifically highlights the importance of achieving information dominance: “We must
have information superiority: the capability to collect, process and disseminate an
uninterrupted flow of information while exploiting or denying an adversary’s ability1
to do the same.” The growing use of precision guided munitions (PGMs) which can
destroy specific targets without extensive collateral damage depends upon the
availability of precise information. As the Department of Defense (DoD) transforms
itself into the force envisioned in Joint Vision 2010 and organizes its components
consistent with “network centric”warfighting concepts, the importance of accurate
and timely information will grow.
There is a consensus among defense policy makers that no single platform or
technology can satisfy DoD’s need for information at all times in all scenarios. The
United States currently employs a variety of satellites that collect information on
enemy forces. These systems are valuable, and their effectiveness and role in
intelligence, surveillance and reconnaissance (ISR) is projected to grow. However,
airborne ISR platforms can be more rapidly and flexibly deployed than current
satellites, and an aircraft’s unpredictable deployment and flight pattern makes it
difficult for adversaries to effectively conceal themselves from observation. Thus,
airborne platforms will likely continue to satisfy a great deal of DoD’s ISR
requirements over the next several decades.
Both Congress and DoD face important decisions regarding current and future
U.S. ISR capabilities. An overarching question is: Over the next 20 to 30 years, what
mix of existing and planned manned and unmanned ISR aircraft most effectively
satisfies DoD’s requirement for timely and accurate information on enemy forces?
The information they collect will be integrated (or “fused”) with information from
satellites, ground-based signals intelligence (SIGINT) intercept sites, human agents,

1 U.S. Joint Chiefs of Staff, Joint Vision 2010, p.16. On May 30, 2000, the Joint Staff
released an updated version, Joint Vision 2020.

and other sources. The particular mix of platforms will depend upon which sensors
they can utilize, geopolitical conditions, and the nature of planned operations.
Many observers believe that ultimately unmanned aerial vehicles (UAVs) will
replace manned aircraft for collecting imagery, radar data, and signals intelligence for
operational commanders. It is not, however, clear that manned airborne
reconnaissance is completely obsolete. Some observers believe that a pilot can react
faster than a distant UAV operator to unexpected targets of opportunity and take
evasive actions that might not otherwise be possible. Also, pilots may be less
susceptible than remote UAV operators to some information warfare techniques.
There remain a variety of manned reconnaissance aircraft in the inventories of the Air
Force and the other services and some attack aircraft can be equipped with
reconnaissance “pods” containing sensors of various types to enable them to serve on
reconnaissance missions.
The U.S. ISR inventory is comprised of a variety of manned and unmanned
aircraft, which have various strengths and weaknesses. (See Table 1 below).
Presently, the U-2 Dragon Lady forms the backbone of this fleet.2 Although based
on a design developed in the 1950s, U-2s have performed admirably in recent
operations. They provided 50% of all imagery during Operation Desert Storm, and
90% of ground forces targeting information. During Operation Allied Force, the U-2
provided more than 80% of the imagery needed for air strikes.3 There is, however,
only a limited inventory of U-2s, they are heavily used, and the plane is expected to
be retired from the Air Force inventory at some point during the next two decades.
Global Hawk UAVs are often suggested as a replacement for U-2s and are
portrayed as the main airborne reconnaissance platform of the future. The first test
version of these planes has been undergoing test and evaluation and there is an
apparent consensus that it should be acquired for the operating forces. The Global
Hawk can operate at altitudes of 65,000 feet and for periods in excess of 30 hours.
Although having the important advantage of not putting pilots at risk, Global Hawks
do not now match all the capabilities of U-2. No Global Hawk is currently in the
operational inventory. Furthermore, current acquisition plans do not call for sufficient
numbers of Global Hawks to replace the hours-on-station that can be maintained by
existing U-2s.
Thus, if Air Force ISR capabilities are to be maintained (and some believe they
need to be expanded if current operations tempos are to be maintained in the future),
a number of serious acquisition and budgetary issues need to be addressed.
!What are the current and anticipated requirements for airborne
surveillance platforms?

2 David Atkinson, “Air Force, CIA Celebrate U-2 Spy Plan History, but Problems Loom.”
Defense Daily. September 18, 1998, p.4.
3 Gigi Whitley, “Air Force Official Praises U-2's Operation Allied Force Performance.”
Inside the Air Force. October 1, 1999, p. 3.)

!Can Global Hawks be designed to have the capabilities now
possessed by the U-2? Or, should multiple UAVs be acquired to
replace a single U-2?
!If a larger or accelerated Global Hawk acquisition effort is approved,
where will funding be identified?
!Should U-2s or other manned aircraft be maintained in the Air Force
inventory even as Global Hawks become operational?
!Are additional U-2s needed, regardless of the introduction of the
Global Hawk?
!What would be the implications for ISR if U-2s were to be
decommissioned at a faster rate than planned to free up funds for
additional or accelerated Global Hawk acquisition?
These questions, and others, will be discussed in the context of the FY2002
Defense budget which the next administration will forward to Congress early in 2001.
Although significant budgetary issues are involved, there are also important
implications for the future effectiveness of ISR and the success of defense planning
for achieving military goals while minimizing the loss of life.
Table 1. USAF Reconnaissance & Surveillance Aircraft Active
Inventory (May 2000)4
Platform Role Number
U-2 Dragon LadyGround and electronic reconnaissance30
RQ-4A Global HawkGround reconnaissance0
E-8 JSTARSGround surveillance, Battle Management, C25
RQ-1A Predator UAVGround reconnaissance6
RC-135 Rivet JointElectronic reconnaissance22
F-16Ground surveillance (SEAD)-
U-2 Dragon Lady
The U-2 is a single-seat, single-engine, high-altitude, reconnaissance aircraft. It
provides continuous all-weather, day or night, stand-off intelligence through all phases
of conflict in direct support of theater military commanders. Long, wide, straight

4 The E-3 AWACS and E-2C Hawkeye also perform surveillance functions in the air-to-air

wings give the U-2 the appearance and characteristics of a glider. The U-2 is a
reliable aircraft with a high mission completion rate.5
U-2s are based at Beale Air Force Base, California and support theater
commanders from four operational detachments located throughout the world, which
have included in recent years: Osan Air Base, South Korea; RAF Akrotiri Air Base,
Cyprus; Sigonella, Sicily; Istres Air Base, France; and Taif and Prince Sultan Air
Bases, Saudi Arabia. U-2 detachments can deploy to other operating locations if
Intended to overfly the vast expanses of the Soviet Union at a time when there
were no satellites, the U-2 was designed to fly at very high altitudes to avoid detection
and attack.6 Beginning in the 1980s an updated version of the U-2 began to replace
the earlier models.7 From 1994 to 1999, U-2R aircraft were upgraded with the
General Electric F-118-10 engine, which burns less fuel, reduces weight and increases
power. The upgraded aircraft were re-designated as a U-2S/ST. The Air Force
expects this airframe and engine combination to last until 2050.8

Figure 1. U-2 Dragon Lady
5 U-2 squadrons in Vietnam achieved a 98% reliability rating. Thornborough, Anthony. Spy
Planes and Other Reconnaissance Aircraft. Arms and Armor Press. London. 1991:44
6 In actuality, however, the Soviets were able early on to track U-2 missions. See Gregory
W. Pedlow and Donald E. Welzenbach, The CIA and the U-2 Program, 1954-1974
(Washington: Central Intelligence Agency, Center for the Study of Intelligence, 1998).
7 The original version of the U-2 made its first flight in August 1955. A significantly larger
and more capable version, the U-2R, first flew in 1967. A tactical reconnaissance version of
the U-2, the TR-1A, first flew in August 1981. (U-2s currently operational are TR-1As.)
Designed for stand-off tactical reconnaissance in Europe, the TR-1 was structurally identical
to the U-2R. The last U-2 and TR-1 aircraft were delivered to the Air Force in October 1989.
In 1992 all TR-1s and U-2s were re-designated U-2R.
8 Bruce Rolfson, “Enhancements Ready U-2s for Years of Duty,” Defense News, June 26,

2000, p. 66.

The U-2 can carry a variety of sensors and cameras depending on its assigned
mission. It is capable of collecting multi-sensor photo, electro-optic, infrared and
radar imagery, as well as performing other types of reconnaissance functions such as
SIGINT collection. Photographic sensors include the HR-329 high resolution camera
and the Optical Bar camera. Electro-optic systems include the Intelligence
Reconnaissance Imagery System III, and the Senior Year Electro-Optical
Reconnaissance System (SYERS), which also collects information in the infra red
(IR) wavelength. These systems vary in resolution and aperture, but when combined,
can capture images of territory on the order of 33 x 21 nautical miles.9 The Advanced
Synthetic Aperture Radar System (ASARS) gives the U-2 real-time, high resolution
– although not as high as EO systems – capability at night and in bad weather (when
the EO systems cannot function effectively) with an improved capability to detect
moving targets.10
The U-2's Senior Glass SIGINT capability is composed of the Senior Ruby
electronic intelligence (ELINT) sensor and the Senior Spear communications
intelligence (COMINT) sensor. These systems can acquire signals and telemetry at
300 nautical miles, downlink data to ground stations 300 nautical miles away, giving
the U-2 a real-time “reach of 600 nautical miles (690 statute miles, 1,110 km). The
Senior Span pod, which is attached to the top of the fuselage allows the U-2 to
transmit SIGINT data via satellites to global ranges.”11 The Senior Spur pod,
performs the same function for ASARS data.12
The U-2 is notoriously difficult to fly. Pilots called the U-2 “Dragon Lady”
because of its unforgiving handling characteristics at altitude.13 Landing the U-2 is
a complex ballet that often entails intentionally stalling the aircraft, employing runway
“chase cars,”and oftentimes deliberately dragging the plane’s wingtip down the
A major challenge for the Air Force is maintaining an adequate supply of U-2
pilots. U-2 pilots face physical rigors that are unique in the aviation world. Flying at
extreme altitudes, pilots must wear pressure suits similar to those worn by astronauts.
The pilots have to engage in special training and pre-flight preparations (e.g., special
diets and inhaling 100% oxygen 1 hour prior to take-off) to help ward off the profuse
sweating, fatigue and dizziness caused by 10 hour missions. There are only some 50
pilots currently qualified to fly U-2s and they have to spend significantly higher
percentages of their tours of duty on temporary flying assignments than other Air
Force officers. Some observers believe that extended deployments and the dangers

9 Anthony Thornborough, Sky Spies: Three Decades of Airborne Reconnaissance. London:
Arms and Armour Press, 1994, p. 24.
10 Bruce Nordwall, “ A Raytheon Program to Improve the Radar for the U.S. Air Force’s U-2
Aircraft,” Aviation Week & Space Technology, March 1, 1999, p. 60.
11 David North, “Venerable U-2 Forges on to Y2K and Beyond,” Aviation Week & Space
Technology, April 12, 1999, p. 60.
12 Col. Bruce Carmichael (Ret) L3 Communications Inc.
13 Anthony Thornborough, Spy Planes and Other Reconnaissance Aircraft. London: Arms
and Armor Press. London. 1991, p.44.

and hardships involved in flying U-2s may contribute to significant retention problems
that could affect overall capabilities. The General Accounting Office (GAO)
concluded that “It is difficult to find pilots with the aptitude required to master the14
difficult handling characteristics of the U-2.” The Air Force has, however, taken
steps to reduce the average temporary additional duty (TAD) rates of U-2 pilots to
bring them into line with other pilots. Improved U-2 pilot morale may have been
influenced by the aircraft winning the Collier Trophy in 1998, awarded by the
National Aeronautic Association for the “greatest achievement in aeronautics or
astronautics in America....”15
U-2s in Post-Cold War Combat Operations.
The U-2 was originally designed to fly over the Soviet Union to acquire
information about strategic targets such as airfields and missile bases. Information
acquired from the U-2 was of importance to the U.S. Intelligence Community’s ability
to provide adequate assessments of Soviet strategic forces, but the utility of the
platform for this purpose was virtually destroyed by the diplomatic embarrassment
following the shoot down of a U-2 in May 1960 and the public trial of its pilot,
Francis Gary Powers. Beginning in the 1960s this mission was taken over by
surveillance satellites that presented no danger of captured pilots. U-2s were not
especially valuable in Vietnam where photography of triple-canopy jungle often
provided little useful intelligence on troop movements along the Ho Chi Minh Trail
underneath. It was not until Desert Storm in 1991 that U-2s demonstrated their value
as the platform that could provide the near-real-time intelligence that allows military
commanders to place bombs on the exact targets intended. The greater use of the U-
2 derived from improvements in surveillance and communications technologies as well
as the much greater availability of precision guided munitions that benefit from U-2-
derived data.
Desert Storm saw the largest U-2 operation in history with nine aircraft and
thirty pilots flying some five sorties a day. Primary missions were Iraqi Army field
positions, bomb damage assessment (BDA), and searching for SCUD missile
launching sites. Photography and other data collected from U-2s was for the first
time rapidly available to tactical commanders. Inevitably, there were arguments about
collection priorities, and, especially, demands by operational commanders for larger
volumes of photographic coverage (especially wide-area coverage) even though some
intelligence officials believed that electro-optic and radar collection was a better use
of assets. There were difficulties with developing photography in-theater and with
disseminating hard copies. Nonetheless, according to one estimate, U-2s provided

30% of total intelligence, 50% of imagery intelligence, and 90% of all Army targeting16

intelligence for the entire theater.

14 U.S. General Accounting Office, “Contingency Operations: Providing Critical Capabilities
Poses Challenges,” (GAO/NSIAD-00-164), July 2000, p. 18.
15 “Lockheed Martin’s U2-S/ER-2 high-altitude wins the Collier Trophy,” Aerospace Daily,
February 11, 1999.
16 Coy F. Cross II, The Dragon Lady Meets the Challenge: the U-2 in Desert Storm (Beale

Military operations over the former Yugoslavia in the mid-1990s saw continued
reliance on the U-2 by military commanders. Balkan missions were initially related
to gathering information on treaty verification, troop dispositions, and missile sites.
During the NATO attack on Serbian forces in the spring of 1999, known as
Operation Allied Force, U-2s were used to identify Serbian targets and to conduct
BDA to determine the accuracy of Allied strikes. Data collected by an airborne U-2
was transmitted back to Beale Air Force Base in California for analysis17 and then sent
back to operations centers and thence to aircraft which could attack the target.
Admiral Daniel Murphy, Commander of the U.S. Sixth Fleet during Allied Force,
recalled having satellite positioning data on key Serbian early warning radars.
But that was insufficient for targeting a Tomahawk missile, which was the weapon
that we intended to employ. So I walked into the intelligence center and sitting
there was a 22-year-old intelligence specialist who was talking to Beale Air Force
Base via secure telephone and Beale Air Force Base was driving a U-2 over the
top of this spot. The U-2 snapped the picture, fed it back to Beale Air Force base
where that young sergeant to my young petty officer said, we have got it, we have
confirmation. I called Admiral Ellis [Commander, Allied Forces Southern
Europe], he called General Clark [Supreme Allied Commander, Europe], and
about 15 minutes later we had three Tomahawk missiles en route and we destroyed18
those three radars.
Another senior Air Force general wrote after the Kosovo campaign, “We never
dropped a bomb on a target without having a U-2 take a look at it.”19
To meet requirements for Allied Force, U-2 pilots and support personnel were
transferred from other theaters. As one senior Air Force commander noted, U-2s
were “stretched to the limit during Allied Force.”20 Observers suggest that if the Air
Force were required to conduct operations on a scale larger than Allied Force, limits
on U-2 availability would have to be faced and could constrain the effectiveness of
precision bombing campaigns.
In addition to missions in the Balkans, U-2s continue to fly collection missions
over Iraq and the Korean peninsula. In those regions they supplement collection by
satellite and other systems and are intended to provide early warning of attacks. Their
chief defense is their ability to operate at altitudes above 70,000 feet, far higher than
most military aircraft and out of the range of most SAMs. U-2s are not, however, by
any means invulnerable. Besides the celebrated shootdown of the plane carrying Gary

16 (...continued)
AFB, CA: 9th Reconnaissance Wing), 1996.
17 At a facility known as a Distributed Common Ground Station (DCGS).
18 U.S. Congress, 106th Congress, 1st session, House of Representatives, Committee on Armed
Services, Military Readiness Subcommittee, Operations in Kosovo: Problems Encountered,
Lessons Learned and Reconstitution, Hearing, October 26, 1999, p. 18.
19 Maj. Gen. William T. Hobbins, quoted in Peter Grier, “U-2 a `Mainstay’ of Allied Force,”
Air Force, December 1999, p. 14.
20 Operations in Kosovo, p. 56.

Powers, a number of other U-2s were lost flying classified missions over the Asian
mainland in the 1960s and 1970s. In the current environment, U-2s can in many cases
collect required information by remaining in international airspace. U-2 overflights
of Iraqi territory, however, have raised concerns about their vulnerability. Fighter
escorts have been assigned to cover them and stiff warnings have been delivered to
Bagdad, threatening dire consequences should efforts be made to attack U-2 missions.
The availability of SAMs to various governments that can reach usual U-2 flying
Figure 2. RQ-4A Global Hawk
altitude represents a standing threat that air force planners must take into
RQ-4A Global Hawk
The RQ-4A Global Hawk is a high altitude, long endurance, long range un-
piloted aerial vehicle designed to perform many of the same functions as the U-2.
Global Hawk is the product of an advanced concept technology demonstration
(ACTD), a program designed to quickly transition emerging technology from the
laboratory to the warfighter.
The program started in May 1994 when the Defense Advanced Research
Projects Agency (DARPA) solicited industry for submissions for a competitive
procurement effort. Phase 2 of the program began in May 1995, when Teledyne
Ryan/E-Systems was selected as the sole contractor (Ryan Aeronautical was
subsequently acquired by Northrop Grumman).21 The Global Hawk undertook its
first flight on February 28, 1998. It flew a second and third time in May 1998. On
March 29, 1999, Global Hawk #2 crashed during a flight at China Lake Naval
Weapons Center, when it “inadvertently received a test signal for flight termination

21 Steven Zaloga. RQ-4A Global Hawk, World Missile Briefing, Teal Group Inc. June 1999.

from a test range on Nellis Air Force Base, Nev.” 22 Global Hawk completed its
ACTD phase in June 2000 and moved into a “normal” acquisition program in
engineering, manufacturing and development (EMD).23 As of October 2000, the
Global Hawk has logged 62 flights for a total of 737 flight hours, 301 of which have
been in airspace controlled by the Federal Aviation Administration (FAA). The
Global Hawk has flown as high as 66,000 feet and for as long as 31 hours at one
time. 24
The Global Hawk’s ground-based support is composed of a Mission Control
Element (MCE) and a Launch and Recovery Element (LRE). These elements are
composed of people (4 in the MCE, 2 in the LRE), computers, communications gear25
and shelters. Together, the MCE and LRE can operate up to three aerial vehicles
simultaneously. The LRE needs to be deployed to the Global Hawk’s operating base,
but the MCEs could theoretically be based anywhere. It takes two C-17 Globemaster
aircraft to deploy the two ground elements. The Global Hawk, as evidenced by a
recent flight from the United States to Portugal, can self deploy.
As currently designed, the Global Hawk can carry electro-optical, IR, and
synthetic aperture radar sensors. It is not designed to carry SIGINT sensors. While
the Global Hawk’s EO and IR capabilities are on-par with the U-2s, its SAR
capabilities are not. Due to greater power and a larger antenna, the U-2 can more
effectively use its SAR to detect moving targets than can the Global Hawk. If used
to find static targets however, the U-2 and Global Hawk SAR capabilities are more
DoD’s current plan is to manufacture twelve Global Hawk air vehicles between
FY2003 and FY2009. These UAVs would carry the EO/IR/SAR sensor payload, and
are described by the Air Force as a complement to the U-2. In FY2009, the Air Force
wants to produce four of the next generation Global Hawks, which could carry
SIGINT sensors, instead of either the EO/IR or the SAR payload. The Air Force
describes the capabilities of this next generation as being on par with the U-2 and26
asserts that they could replace the U-2.
Summary: Platform Comparisons
A review of Table 2 below highlights the key similarities and differences between
the U-2 and Global Hawk. On a one-to-one basis, a comparison of these

22 Sue Baker. “Results of Global Hawk Accident Investigation Board Released, Air Force
News. December 23, 1999.
23 Endurance Unmanned Aerial Vehicles. Exhibit R-2 (PE0305205F), Department of the Air
Force, February 2000:1427.
24 LtCol Ken Bray. Briefing on the Global Hawk System: Program Overview, Department of
the Air Force, AQIJ. October 19, 2000.
25 Like manned aircraft, the Global Hawk also requires operations and maintenance and
logistical manpower and support.
26 LtCol Ken Bray. Briefing on the Global Hawk System: Program Overview. Department of
the Air Force, AQIJ. October 19, 2000.

characteristics is important for policy makers to consider when making decisions on
the overall size and composition of the U.S. airborne ISR force structure. There are
significant similarities. The platforms are of similar physical dimension. They fly at
approximately the same altitude and at similar speeds. Yet, there are important
differences between the platforms that stand out when comparing the U-2 and Global
Hawk on a platform-to-platform basis. These differences include (1) pilot
requirements, (2) range and endurance, and (3) mission payload.
The first difference between the platforms is the Global Hawk’s lack of a pilot.
While not putting a pilot in danger appears obviously beneficial, there are a number
of associated issues that merit discussion. One potential downside to being pilotless
is that the platform is not as responsive to changing circumstances as a piloted
aircraft. Remotely located mission control personnel cannot, in theory, make decisions
and take action as quickly as a pilot on the scene. However, during a mission, U-2
pilots infrequently take action based on what they personally observe from the
cockpit. Rather, they typically make adjustments to their pre-planned mission profile
based on warnings and orders from mission control elements. Thus, unmanned aircraft
may not suffer from a lack of responsiveness in the high altitude ISR mission as they
would if performing other missions.
The lack of a pilot may be more of a hindrance when flying through civil-
controlled U.S. and foreign-country airspace than it is when overflying a combat area.
Civil authorities are concerned that in the event of an unforeseen emergency, such as
an engine burnout, or malfunction, a pilotless aircraft would be less able to take
corrective action, such as making a controlled landing at a local airfield. Instead, they
fear that a pilotless aircraft would be more likely to crash into inhabited areas.
Therefore, civil authorities currently impose very demanding mission planning
requirements on unmanned systems; if they allow them to overfly at all. This
exhaustive mission planning takes time, manpower and money.
Finally, the Global Hawk’s lack of a pilot doesn’t necessarily confer increased
operational utility. The Global Hawk’s size, flight profile and lack of stealth features
suggest it is approximately as survivable as the U-2. It will likely be employed as the
U-2 is – outside of high threat environments such as long-range SAMs. At
approximately $50 million each, the Global Hawk is too expensive to be considered
The second difference between the Global Hawk and U-2 that bears discussion
is that of range and endurance. The Global Hawk has superior range and endurance
to the U-2. Global Hawk can fly approximately twice as far as the U-2, and its loiter
time is three times that of the U-2. This suggests important ramifications for the
number of platforms required in the overall ISR inventory. All other things being
equal, fewer platforms with long endurance can do the same job as more platforms
with less endurance.
The third noteworthy difference between the platforms is payload. The U-2
enjoys an advantage in payload over the Global Hawk of more than two-to one. This
allows it to carry more and different payloads. A larger payload capability also
provides more potential for unforseen upgrades and tradeoffs. Generically speaking,
a larger volume on an aircraft presents engineers with more choices and opportunities
than a smaller volume. Additionally, the U-2's large engine provides more electrical

power than the Global Hawk’s, which in turn increases the capabilities of some of its
sensor payloads. All things being equal, fewer platforms with more sensors can do
the same job as more platforms with fewer sensors.
Table 2. Comparison of Key Characteristics
U-2Global Hawk
ContractorLockheed Aircraft CorpNorthrop Grumman/Raytheon
DimensionsLength: 63 feetLength: 44 ft
Height: 16 feetHeight: 15 ft
Wingspan: 103 feetWingspan: 116 ft
PerformanceRange: >7,000 miRange: 14,400 mi
Speed: >475 mphSpeed: 400 mph
Ceiling: >70,000 ftCeiling: 65,000 ft
Payload: 4,700 lbsPayload: 2,000lbs
Endurance: 10+ hours (pilot limited)Endurance: 35 hours
Engines1 F118-GE-101 Turbofan1AE 3007 Turbofan
(17,000 lbs thrust)(7,200 lbs thrust)
Payload (lbs)4,7002,000
CostEstimated Procurement Unit Cost:27Estimated Procurement Unit Cost:28
($M/FY01) $52.8/aircraft $51.6/aircraft
Congressional Action
Congress has long taken a special interest in U-2 programs. In the past decade,
the planes have been re-engined to enable them to fly at higher altitudes for longer
periods. A variety of improved sensors and communications data-links have been
acquired or funded and necessary steps are being taken to install them on aircraft. A

27 The USAF refurbished 35 U-2/TR-1s from FY80-FY87 for $1.738 billion in constant FY96
dollars. This figure does not include amortized R&E spending nor procurement spending since 1997.
(Source: Table of Actual and Projected Weapons Purchases 1974-1997.Congressional Budget Office
Mimeo, Washington, DC, March 17, 1995.) FY96-to-FY01 adjustment made using DoD Deflator
of 93.9.
28 This figure is derived from dividing the weapon system cost by the number of Global Hawk’s
procured (8) FY2002 to FY2005. It does not consider the 8 additional aircraft the Air Force wants
to procure from FY2006 to FY2009 (data unavailable), nor does it factor in the $188.5 million that
has been spent on Global Hawk RDT&E. This money, the $306.6 million in RDT&E funds
requested from FY2001 to FY2005 and additional RDT&E funds that will be requested beyond
FY2005 (if any) will need to be amortized across the entire Global Hawk program to achieve a total
program unit cost figure.

cockpit upgrade is underway that will bring control systems in the U-2 up to current
Air Force standards. The U-2 has been declared a “congressional interest item.”
The need of the regional military commanders (CINCs) for tactical airborne
intelligence capabilities is universally acknowledged within DOD. U-2s and UAVs
are both in high demand and the inventories (“density”) of both types of platforms are
low. Although, according to some observers, the Clinton Administration may have
been somewhat more inclined to deploy forces in “peacekeeping” missions than either
of its likely successors, most analysts believe that U.S. military forces will not escape
the types of missions in disparate countries that will require precise intelligence of
potential targets. These missions are as likely to occur in the next few years as they
are in 2010 or 2020.
DoD’s current plans aim to provide today’s and future warfighting CINCs with
adequate ISR. Planning envisions the continued upgrading of the U-2, possibly
augmenting it, and eventually replacing it with the Global Hawk UAV. ISR for the
foreseeable future will inevitably be limited by availability of airborne platforms. At
present there are only some 35 U-2s, the number of pilots and ground crew is limited;
and there no operational Global Hawks. Many observers believe that, even if UAVs
can ultimately replace the entire U-2 force, many more units than currently envisioned
will be required as well as an extensive period of operational familiarization and
DoD Budget FY 2001
In considering the FY2001 Defense budget, the four major oversight committees
– House Armed Services, Senate Armed Services, House Appropriations, and Senate
Appropriations – expressed concern regarding U-2 procurement issues such as the
Senior Year Electro Optical Reconnaissance System (SYERS), the Joint Signals
Intelligence Avionics Family (JSAF), and the acquisition of a two-seat training
Some oversight committees expressed concern that the administration’s budget
request underfunded initial deployment spares for the SYERS upgrade by at least $3.0
million. Authorization conferees recommended a $3 million increase to remedy this
concern, while appropriations conferees did not. Also, there was consensus among
the defense oversight committees that the Air Force required additional RDT&E
funds to adequately support continued development of the U-2 SYERS. A
polarization technique that would provide the SYERS with increased ability to
penetrate foliage and camouflage was expressly supported in congressional language.
The JSAF would provide an upgraded information collection capability for the
U–2s. Yet, the administration’s request was insufficient to procure an entire JSAF
suite and required spares and cabling. Therefore, appropriations and authorizations
conferees recommended an increase to the Defense Airborne Reconnaissance
Program (DARP) of $8 million for an additional JSAF unit for the U-2.
There are currently four two-seat U-2 training aircraft in DoD’s inventory, and,
as discussed earlier, producing sufficient numbers of U-2 pilots is a constant concern.
To remedy this, House authorizers recommended making available an additional $10

million and $14 million respectively to procure a fifth two-seat U-2 trainer; and House
appropriators supported that authorization. Appropriations and authorization
conferees noted that $111.6 million and $14 million had already been made available
for U-2 sensor improvements and a U-2 trainer respectively in the FY2000
Supplemental Appropriations Act (P.L. 106-246) enacted on July 13, 2000. (H.R.
4425, 106-710. p 133) Appropriations and authorization conferees therefore reduced
funding for U-2 related procurement below the administration’s request.
While supporting the Administration’s request for $373.1 million in U-2 (and
RC-135) operations and maintenance funding, House authorizers expressed concern
that “funding for many Intelligence Community programs, including intelligence
surveillance and reconnaissance (ISR) aircraft are regularly transferred from the pro-
grams for which funds were authorized and appropriated to fund shortfalls in other
programs, often not related to ISR requirements.”29 Noting testimony by regional
CINCS that shortfalls in ISR aircraft and systems were a top priority, the House
Armed Services Committee directed that the RC-135 and U-2 programs be designated
as congressional interest items.
Table 3: Summary of U-2 & Global Hawk Funding FY2001
(in millions $)
Request HASC SASC Auth. HAC SAC Approps.
Aircraft Procurement, Air Force
SYERS 0 3.0 8.0 3.0 0 3.0 0
U-2 DARP 165.5243.7168.5152.3180.2276.6159.2
(Line 56)
U-2 DARP 98.4128.6106.411.1136.798.414.0
(Line 80)
HAE UAV22.322.3022.322.322.322.3
(Global Hawk)
RDT&E, Air Force
U-2 JMIP27.531.533.532.531.533.532.5
Endurance 109.2 109.2 127.2 109.2 109.2 127.2 127.2
(Global Hawk)
The Air Force FY2001 budget requested $22.3 million in procurement
funding and $109.2 million in RDT&E funding for the HAE UAVs. The $22.3

29 U.S. Congress, 106th Congress, 2d session, House of Representatives, Committee on Armed
Services, Floyd D. Spence National Defense Authorization Act for Fiscal Year 2001, H.Rept.

106-616, May 12, 2000, p. 330.

million would be used for procurement of long lead items for the first two
production Global Hawk UAVs and one common ground station. Continued
development of the Global Hawk would be supported by $103.2 of the $109.3
million total for this line item. All defense oversight committees except the Senate
Armed Services Committee supported the procurement request. The SASC
concurred with a recent GAO report that found it premature to enter into
production in FY 2001 and zeroed out the request.30
The House Armed Services and Senate Appropriations committees matched
the administration’s request for RDT&E funding. Expressing interest in the
potential of Global Hawk to support counter-drug activities, the Senate Armed
Services committee increased the RDT&E request by $18 million so Global Hawk
engineers could explore the integration and use of an AESA (advanced
electronically steered array) radar.31 The Senate Appropriations Committee and
Appropriations conferees also supported an $18 million increase; but the House
did not. Authorization conferees adopted the AESA provision language but did
not increase funding accordingly.
Intelligence Budget FY 2001
Some information on actions taken by the Congress on intelligence programs
associated with the U-2 and the Global Hawk is available from committee reports on
intelligence authorization bills. The published reports are, however, accompanied by
classified annexes that provide greater detail and have legal authority. The reports
also provide a sense of congressional opinion. In May 2000, the House Intelligence
Committee concluded:
In the area of Intelligence, Surveillance and Reconnaissance (ISR) assets, we
continue to see extensive over-utilization of very limited, but critical airborne
assets, with little relief in sight. While planning for deployment of new ISR
airborne capabilities into the theaters, the Department of Defense has taken money
from existing, supposedly complementary, platforms to pay for future capabilities.
The result: our overall ISR capabilities and resources are decreasing at a time32
when our military forces are relying on them more and more.
The House Committee approved the Administration’s total request of $373.1 for
operations and maintenance of the U-2 and RC-135 while designating them as
congressional interest items. It also recommended increased funding for various U-2
modifications, including $3 million for initial deployment spares for the SYERS
upgrade and $8 million for JSAF as well as the conversion of one U-2 into a trainer.
Taken together the House Intelligence Committee recommended $132.6 million, an
increase of $34.2 million for U-2 modifications. The Senate Intelligence Committee

30 U.S. Congress, 106th Congress, 2d session, Senate, Committee on Armed Services, National
Defense Authorization Act for Fiscal Year 2001, S.Rept. 106-292, May 12, 2000, p. 139.
31 S.Rept. 106-292, p. 401-402.
32 U.S. Congress, 106th Congress, 2d session, House of Representatives, Permanent Select
Committee on Intelligence, Intelligence Authorization Act for Fiscal Year 2001, Report, May

16, 2000, H.Rept. 106-620, p. 9.

did not provide similar details on its views on the U-2 or the Global Hawk nor were
these actions reflected in the intelligence authorization conference report.33 It is
likely, however, that House Intelligence Committee actions were consistent with those
taken by the House Armed Services Committee.
The budgeting and funding of airborne reconnaissance programs are complicated
by overlapping roles of intelligence agencies and congressional intelligence oversight
committees on one hand and, on the other, by the military departments (in this case
the Air Force) and their congressional overseers in the armed services and
appropriations committees. There is coordination between intelligence and defense
programs both within the executive branch and among congressional committees, but
some observers believe that the ISR platforms inevitably come out second best in
competition with bombers and fighter aircraft. In May 2000 the House Intelligence
Committee stated that it “is concerned that funding from many intelligence
Community programs, including intelligence surveillance and reconnaissance ISR)
aircraft are regularly transferred from the programs for which funds were authorized
and appropriated to fund shortfalls in other programs, often not related to ISR
requirements.”34 In this as in other areas, current pressures on defense spending
inevitably complicate efforts to provide adequate resources for U-2s, Global Hawk
UAVs, and other ISR programs.
There are also longstanding concerns that the relationships between space-based
and airborne surveillance platforms, and between “national” and tactical systems are
not always well balanced. Some observers question the extent to which systems have
been designed to maximize the usefulness of systems to both national and tactical
consumers, suggesting that bureaucratic obstacles more than technological limitations
may inhibit use by multiple consumers.
Issues and Options
The Air Force, persuaded that Global Hawk will meet many, if not all, its
airborne surveillance requirements, is inclined to accelerate the acquisition effort
beyond the twelve Global Hawks planned for FY03-FY09. To supply the $960 million
required in additional funding, Secretary of the Air Force Whitten Peters has said that
he is considering reductions in the U-2 program beginning in FY2006 and retirement
of all U-2s by FY2011.35 This will inevitably be a controversial decision. The U-2
is one of the most heavily deployed aircraft in the Air Force’s inventory, widely
acclaimed by the CINCs, and the beneficiary of a series of expensive upgrades in
recent years that have elongated its service life. A “congressional interest item,” the
U-2 is the “bird in the hand” whereas the Global Hawk has yet to be fielded. A

33 U.S. Congress, 106th Congress, 2d session, House of Representatives, Committee of
Conference, Intelligence Authorization Act for Fiscal Year 2001, October 11, 2000, H. Rept.


34 Ibid., p. 27.
35 Amy Butler. “Peters: Global Hawk Acceleration Needed for Key 2004 Decision Point,”
Inside the Air Force, October 27, 2000.

formal decision to retire the U-2 early to free up funds for additional UAVs will likely
be given close scrutiny by Congress and the public.
Advocates of the proposal note that Global Hawks have performed well in tests.
They argue that the Global Hawk’s long endurance gives it the ability to perform the
U-2's imagery collection missions with fewer platforms. Furthermore, future upgrades
and reconfigurations will give Global Hawk the U-2's SIGINT collection capability.
To lay the groundwork for future airborne surveillance capabilities, it is reasonable,
according to this view, to retire the U-2s beginning in 2006 rather than gradually
phasing them out by attrition and make instead the investment in the next generation
of airborne reconnaissance platforms.
Air Force options on Global Hawks and U-2s appear to be based on the
assumption that funding must be adjusted within overall limits on spending for ISR
programs. Apparently an early termination of the U-2 effort is the most acceptable
way for the Air Force to identify funding for a trade-off to fund accelerated
acquisition of the Global Hawk within its budgetary constraints. Some observers
suggest that Air Force officials may anticipate that, at some point, funding might be
identified elsewhere within the defense budget or that Congress might provide funding
specifically for additional Global Hawks. One report noted, “some service sources
say it is unlikely the Air Force will be able to come up with the money without
significant help from OSD [Office of the Secretary of Defense] or Congress.”36
Opponents of the proposal believe that the two systems should operate
simultaneously. They argue that, considering the very high demand for today’s
innumerous airborne ISR assets, it is essential that the Air Force increase today’s ISR
capabilities, not just replace them on a one-to-one basis. Opponents of Secretary
Peters’s proposal also argue that the U-2 should not be phased out until the Global
Hawk is produced and employed in large numbers, and its operational capabilities and
limitations are well understood. This, they say, would ensure a smooth transition from
today’s ISR fleet to tomorrow’s, and would ensure that the replacement of U-2s does
not result in a loss of an essential capability.
Opponents also argue that decommissioning all U-2s which, as a result of
extensive investment in upgrades have an expected service life of up to 50 more years,
would be wasteful of an important capability. They note that whereas fewer UAVs
than U-2s might be needed for the same mission if they were identically equipped, the
actual number of Global Hawks required might vary since they cannot (at least at
present) carry the same set of collection systems as the U-2. Furthermore, they
contend, it is unclear when Air Force scientists will be able to overcome the
technological impediments that currently limit the Global Hawk’s payload.
There may be other options that could be pursued to maintain or improve DoD’s
aerial ISR capability until the Global Hawk is optimally configured, and produced in
sufficient quantities, to replace the U-2. These options include (1) increasing the
number of operational U-2s; (2) more effectively managing the existing U-2 inventory;

36 Amy Butler, “Peters Accelerates Global Hawk Sensor Development, Block 10 Buys,”
Inside the Air Force, September 29, 2000, p. 6.

(3) attracting and retaining more U-2 pilots; or (4) returning the SR-71 aircraft to
active service.
There are currently 31 operational U-2s with another four used as trainers. At
any one time, three of the 31 operational U-2s are in depot for maintenance. Since
it takes five U-2s to maintain a 24 hour orbit37, these 28 U-2s can theoretically
operate in five to six different spots on the globe at the same time. Given the limited
inventory of U-2s, a key concern is the foreseeable loss of aircraft through accidents
and attrition. In recent years, one U-2 has been lost through attrition every two years.
If this rate persists, by 2008 the Air Force would only have enough U-2s to provide

24 hour coverage of four to five different spots at any one time.

Some urge the procurement of additional U-2s by reopening the production line.
This idea has received some congressional attention.38 Some observers believe that
this may be a cost-effective way to make additional platforms available in a relatively
short period of time. The technology is well-proven under operational conditions and
acquiring new platforms would not require long lead-times for research and
development and costs would be relatively manageable.
Others argue that such a step would be counterproductive in that the Air Force
would have a fleet of U-2s of varying ages which would present maintenance
problems at some point. Furthermore, they suggest that the U-2 is representative of
decades-old technology and is difficult to fly. Also, the U-2 production line has lain
fallow for approximately 20 years. Is re-opening this line feasible? If so, at what cost?
Another key consideration is manning; the U-2 requires specially trained pilots whose
employability in other Air Force positions becomes limited. Most importantly, it
places pilots at risk of death or capture. Proponents of re-opening the U-2 line
counter, however, that it should be possible to manufacture future U-2s that don’t
require a pilot. The additional costs of re-designing the U-2 to fly without a pilot are
unclear, but advances and technologies developed under the Global Hawk and other
UAV programs could probably be exploited.
Another important action that could be taken to relieve the high operational
tempo felt by the U-2 force would be to attract more pilots to the program and better
retain the ones already qualified to fly the Dragon Lady. U-2 proponents suggest that
Congress may wish to enquire about steps the Air Force has or has not undertaken
to attract more pilots into the U-2 program. What, for example, would be the impact
on overall recruitment and retention if the Air Force were to dictate that a greater
percentage of its pilots enter the U-2 program?
Options may also exist to more effectively manage DoD’s current U-2 inventory.
For instance, only four U-2 training aircraft exist. This lack of trainers could slow the

37 Each aircraft flies an 8 hour mission. To maintain three U-2s in theater for an extended
period of time, the Air Force needs to rotate five aircraft through the mission. At any one time
three U-2s will be in theater, a fourth is deploying to theater, and the fifth is returning home.
38 U.S. Congress, 106th Congress, 2d session, House of Representatives, Conference Report,
Making Appropriations for the Department of Defense for the Fiscal Year Ending September

30, 2001, and For Other Purposes. July 17, 2000, H. Rept. 106-754. p.199.

pace of preparing new U-2 pilots for their missions. It is feasible that two-seat
training aircraft could be used to fly operational missions if required, though with
diminished capabilities. However, the 31 single-seat aircraft used to fly operations
can’t be used to train new pilots. Therefore, the reduction in ISR capability caused by
converting a handful of single-seat U-2s to two-seat trainers may be outweighed by
the improvement in training capabilities.
Another inventory management issue that might be examined is the U-2's foreign
basing arrangements. In addition to bases in the United States, U-2s currently operate
from five air bases located in France, Cyprus, Spain, South Korea, and Saudi Arabia.
The Air Force is currently withdrawing the U-2 from the French and Cypriot
locations. Fewer forward bases may mean that U-2s could spend a greater percentage
of their 10 hour missions transiting to and from the theater to be observed, and less
time collecting intelligence. Additional U-2s would be required to overfly the theater
to maintain the same amount of coverage. Base consolidation has been justified by
the dissolution of the Soviet Union. Yet there has also been a proliferation of smaller
scale contingencies in which the United States has an interest. This raises questions
about the efficacy of reducing the U-2's operational basing by two fifths at a time of
high operational tempo. Some observers have suggested that examining the utility
of opening additional U-2 bases in different theaters may be in order.
Another inventory management issue pertains to the Expeditionary Air Force
concept. To increase deployment predictability and more evenly distribute the
deployment burden, the Air Force is dividing its people and forces into 10 Air
Expeditionary Forces (AEFs). These AEFs are loose amalgams of resources that will
rotate through set training and deployment cycles. Currently, the Air Force does not
have a similar strategy for its “high demand, low density” (HD/LD) assets such as the
U-2. Instead, U-2s are sent to a given theater as demand rises. Some within DoD have
suggested that the U-2 and other ISR assets could be included in the current AEF
concept and thus increase U-2 deployment predictability. This idea may help
distribute the deployment burden throughout the U-2 force, but may not reduce the
deployment tempo, due to low numbers of operational platforms. Another suggested
option is to devise an AEF-like inventory management scheme specifically for the U-


Different variants of the Global Hawk may have to be developed and other
UAVs or manned aircraft may be acquired. The Global Hawk is not the only UAV
potentially available, but it has been designed to meet certain DoD requirements for
range and endurance. Configuring smaller UAVs, such as the Predator, to accomplish
at least some of Global Hawk’s mission capabilities might be feasible, but would
entail considerable delays and could come at the cost of other operational capabilities.
Yet, this idea may merit further investigation.
A final option that may bear investigation is to “un-retire” a handful of SR-71
Black Bird aircraft. Proponents of this approach point out that the SR-71 was a very
capable ISR asset. Its very high speed contributed to the SR-71's survivability, and
increased the potential volume of territory that could be surveilled. Also, several SR-
71 airframes still exist. They have been preserved at the Air Force facility in
Palmdale, California. Also, SR-71 aircraft have been “un-retired” in the past.
Opponents of this idea point out that the SR-71 was a very expensive aircraft to fly

and maintain, and that flying just a handful would not be cost effective. Also, the
airframes may exist, but what about pilots? Are there any pilots qualified to fly the
aircraft? Are there any pilots qualified to teach and train pilots? Opponents of this
idea argue that un-retiring the SR-71 would be too expensive a measure to simply
bridge the gap between the U-2 and Global Hawk.
It is likely that Congress will play a key role in dealing with the futures of the
Global Hawk and the U-2. Direct congressional interest in UAVs is longstanding and
funding and policy direction for the Global Hawk has been reflected in a series of
appropriations and authorization acts. Similarly, Congress has also monitored the U-2
program closely in recent years, identifying funding for upgrades to the aircraft and
for additional surveillance and communications equipment. Plans for the early
retirement of the U-2 force will undoubtedly be viewed with care and there will be
interest in the progress of Global Hawk acquisition and its integration into the
operating forces.

Appendix 1: Abbreviations and Acronyms
ACTDAdvanced Concept Technology Demonstration
AEFAir Expeditionary Force
ASARSAdvanced Synthetic Aperture Radar System
BDABattle Damage Assessment
CINCCommander In Chief (of a U.S. Unified or Specified Command)
COMINTCommunications Intelligence
DARPDefense Airborne Reconnaissance Program
DoDDepartment of Defense
ELINTElectronic Intelligence
EMDEngineering, Manufacturing and Development
EOElectro Optical
FAAFederal Aviation Administration
GAOGeneral Accounting Office
HD/LDHigh Demand, Low Density
IOCInitial Operational Capability
IRInfra Red
ISRIntelligence, Surveillance, and Reconnaissance
LRELaunch, Recovery Unit
JSAFJoint Signals Intelligence Avionics Family
MCEMission Control Element
PGMPrecision Guided Munition
RDT&EResearch, Development, Test and Evaluation
SARSynthetic Aperture Radar
SIGINTSignals Intelligence
SLARSide Looking Airborne Radar
SYERSSenior Year Electro Optical Reconnaissance System
TADTemporary Additional Duty
UAVUnmanned Aerial Vehicle