a

GAO

United States Government Accountability Office

Report to the Chairman, Subcommittee 

on Tactical Air and Land Forces, 

Committee on Armed Services, 

House of Representatives

November 2004 UNMANNED AERIAL 

VEHICLES

Changes in Global 

Hawk’s Acquisition 

Strategy Are Needed 

to Reduce Program 

Risks

GAO-05-6
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

www.gao.gov/cgi-bin/getrpt?GAO-05-6.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Michael J. 

Sullivan at (202) 512-4163 or 

sullivanm@gao.gov. 

Highlights of GAO-05-6, a report to the 

Chairman, Subcommittee on Tactical Air 

and Land Forces, Committee on Armed 

Services, House of Representatives 

November 2004

UNMANNED AERIAL VEHICLES

Changes in Global Hawk’s Acquisition 

Strategy Are Needed to Reduce Program 

Risks 

The restructuring of the Global Hawk program impacts the acquisition 

program in multiple ways. 

• More and accelerated funding: Funding, which previously spanned 

20 years, now is compressed in about half the time. The restructured 

plan requires $6.3 billion through fiscal year 2012; the original plan 

would have needed $3.4 billion by that time. The budget request is now 

three times higher for some years (see figure below). 

• Immature technologies: Several critical technologies needed to 

provide the advanced capabilities are immature and will not be tested on 

the new air vehicle until late in the program, after which most of the air 

vehicles will already have been bought. 

• New requirements, new costs: DOD’s desire to add additional Global 

Hawk capabilities tripled development costs. The program acquisition 

unit cost increased 44 percent since program start, yet fewer vehicles are 

to be produced than originally planned. 

• Challenges, trade-offs, and delays: The addition of new capabilities 

has led to space, weight, and power constraints for the advanced Global 

Hawk model. These limitations may result in deferring some capabilities. 

Some key events and activities—many related to testing issues—have 

been delayed. 

Global Hawk’s highly concurrent development and production strategy is 

risky and runs counter in important ways to a knowledge-based approach 

and to DOD’s acquisition guidance. The restructuring caused gaps in product 

knowledge, increasing the likelihood of unsuccessful cost, schedule, quality, 

and performance outcomes. Because the restructured program is 

dramatically different from the initial plan for the basic model, the business 

case now seems out of sync with the realities of the acquisition program. 

Global Hawk’s Annual Funding Requirements 

Sources: Air Force (data); GAO (analysis).

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

2001

2003

2005

2007

2009

2011

2013

2015

2017

2019

800

600

400

200

0

Funding, as of December 2003, after 

restructuring (in millions of then-year dollars)

Funding, as of September 2001, before restructuring 

(in millions of then-year dollars)

Years

Global Hawk offers significant 

military capabilities to capture and 

quickly transmit high-quality 

images of targets and terrain, day 

or night, and in adverse weather—

without risk to an onboard pilot. 

Global Hawk first flew in the late 

1990s as a demonstrator and 

supported recent combat 

operations in Afghanistan and Iraq. 

In 2001, the Air Force began an 

acquisition program to develop and 

produce improved Global Hawks. 

In 2002, the Department of Defense 

(DOD) restructured and 

accelerated the program to include 

a new, larger and more capable air 

vehicle. GAO was asked to review 

the program and discuss (1) the 

restructuring’s effect on the Air 

Force’s ability to deliver new 

capabilities to the warfighter and 

(2) whether its current business 

case and management approach is 

knowledge-based and can help 

forestall future risks. 

What GAO Recommends

GAO recommends the Air Force 

revisit the decision to concurrently 

develop and produce the newer 

Global Hawk and create a new 

business case that defines 

warfighter needs and available 

resources. GAO also recommends 

that production be delayed (other 

than those units needed for testing) 

until the new business case is 

approved. DOD disagrees that 

these actions are needed because it 

believes risks are being managed 

effectively and GAO’s approach 

would require more time and 

money to implement the program. 
Page i GAO-05-6 Global Hawk Acquisition

Contents

Letter 1

Results in Brief 3

Background 4

Restructured Global Hawk Program Attempts to Do More 

in Less Time 7

Global Hawk Program’s Current Management Approach Sets Stage 

for Additional Risks 16

Conclusions 23

Recommendations for Executive Action 24

Agency Comments and Our Evaluation 24

Appendixes

Appendix I: Scope and Methodology 29

Appendix II: Comments from the Department of Defense 30

Appendix III: Knowledge Gaps at Critical Knowledge Points 35

Related GAO Products 39

Tables Table 1: Key Characteristics of Global Hawk RQ-4A and RQ-4B 

Models 6

Table 2: Global Hawk Program’s Cost, Quantity, and Unit Costs 12

Table 3: How Global Hawk Product Knowledge Compares with 

Three Critical Points in the Knowledge-Based 

Approach 20

Figures Figure 1: Global Hawk RQ-4A 5

Figure 2: Global Hawk’s Annual Funding Requirements 8

Figure 3: Restructured 2004 Plan Is Highly Concurrent Compared 

with Original Global Hawk Plan 11

Figure 4: Global Hawk Program Is Not Fully Aligned with DOD’s 

Acquisition Policy and Knowledge-Based Approach 19
Contents

Page ii GAO-05-6 Global Hawk Acquisition

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Page 1 GAO-05-6 Global Hawk Acquisition

United States Government Accountability Office

Washington, D.C. 20548

A

November 5, 2004 Letr

The Honorable Curt Weldon

Chairman

Subcommittee on Tactical Air and Land Forces

Committee on Armed Services

House of Representatives

The Air Force’s Global Hawk is a high-flying unmanned aerial vehicle that 

can capture detailed images of targets as well as wide swaths of terrain and 

transmit those images on a near real-time basis to battlefield commanders 

and intelligence centers. With an ability to see through clouds, sandstorms, 

and other inclement weather conditions day or night and to fly for more 

than a day, Global Hawk can significantly improve the Department of 

Defense’s (DOD) ability to gather intelligence, surveillance, and 

reconnaissance1

 information about potential adversaries without risking an 

onboard pilot. An early model performed well in the ongoing global war on 

terrorism, and the Secretary of Defense identified Global Hawk as having 

the potential to transform military operations. The Air Force began the 

acquisition program in 2001. With total program cost estimated at 

$6.3 billion, Global Hawk is currently DOD’s most expensive unmanned 

aerial vehicle. The Navy is considering Global Hawk for a maritime 

surveillance mission, and other federal agencies, several foreign countries, 

and the North Atlantic Treaty Organization have all expressed an interest in 

this aircraft system.

1

 Intelligence is defined by DOD as the product resulting from the collection, processing, 

integration, analysis, evaluation and interpretation of available information concerning 

foreign countries or areas. DOD also defines the term as information and knowledge about 

an adversary obtained through observation, investigation, analysis, or understanding. 

Surveillance is defined by DOD as the systematic observation of places, persons, or things 

through visual and other means. DOD defines reconnaissance as a mission undertaken to 

obtain, by visual observation or other detection methods, information about activities and 

resources of an enemy or potential enemy or to secure data characteristics of a particular 

area.
Page 2 GAO-05-6 Global Hawk Acquisition

In 2002, DOD restructured the program, accelerating development and 

production, and, more importantly, changing the design significantly to a 

new, larger, heavier, and more capable air vehicle to handle both imagery 

and signals intelligence missions.2

 Given Global Hawk’s overall importance 

to DOD, you asked us to review the program. This report discusses (1) the 

restructuring’s effect on the Air Force’s ability to deliver new capabilities to 

the warfighter in terms of funding, acquisition strategy, cost, and other 

related issues and (2) whether the current business case and management 

approach is knowledge-based and can help forestall future risks.

To determine the effects of restructuring on the Global Hawk program’s 

cost, schedule, and performance goals, we reviewed the original 

acquisition strategy, two major restructurings, and the current acquisition 

strategy. We assessed changes to funding, annual budget requests, the 

number of vehicles to be procured, vehicle capabilities, and program cycles 

for developing, testing, and procuring Global Hawk. To evaluate the 

program’s likelihood of meeting its objectives, we compared the current 

acquisition strategy with criteria established in DOD’s acquisition policy3

and with best practices and experiences of leading commercial firms and 

successful government acquisitions. This methodology, which we call a 

knowledge-based approach, enabled us to evaluate whether the program 

achieved product knowledge at the right times in terms of technology, 

design, and production maturity. We identified gaps in product knowledge, 

reasons for those gaps, and risks associated with inadequate knowledge. 

We performed our review from February 2004 to September 2004 in 

accordance with generally accepted government auditing standards. More 

details about our methodology are in appendix I.

2

 Imagery intelligence is defined by DOD as being derived from the exploitation of collection 

by visual photography, infrared sensors, lasers, electro-optics, and radar sensors (such as 

synthetic aperture radar sensors) wherein images of objects are reproduced optically or 

electronically on film, electronic, display devices, or other media. DOD defines signals 

intelligence as involving intelligence derived from communications, electronic, and foreign 

instrumentation signals.

3

 DOD Directive 5000.1 “The Defense Acquisition System” and DOD Instruction 5000.2 

“The Operation of the Defense Acquisition System,” both dated May 12, 2003.
Page 3 GAO-05-6 Global Hawk Acquisition

Results in Brief The Global Hawk program has changed dramatically since the March 2001 

decision to start both system development and low-rate production. The 

program has been restructured twice to add the requirement for a totally 

new and larger Global Hawk design to be developed and produced in less 

time. Program funding, which previously had been stretched relatively 

evenly across 20 years, is now compressed into roughly half the time, 

tripling Global Hawk’s budgetary requirements in some years. In fiscal year 

2006, for example, the program now plans to request about $750 million 

from Congress, three times what was planned originally. The restructurings 

expanded the development period by 5 years and compressed production 

by 9 years, creating significant concurrency between development and 

production from fiscal year 2004 to 2010. Because of this concurrency, the 

Air Force plans to invest in almost half of the total fleet of the new larger 

Global Hawks before a production model is flight-tested and completed to 

show that the air vehicle design works as required. Likewise, full-rate 

production will begin before the airborne signals intelligence and 

multiplatform radar (the two required capabilities justifying the new, larger 

model) complete development and are flight-tested to prove the integrated 

system will work as intended. The primary reason for building the RQ-4B 

model was to integrate and carry the advanced sensors to provide added 

capability to the warfighter. The program’s total cost estimates have 

increased by nearly $900 million, driven by a threefold increase in 

development costs to pay for the development of a new and larger air 

vehicle. As a result, the program acquisition unit cost increased 44 percent 

since the program started. Finally, in the past 2 years, the program has 

deferred some key capabilities and experienced delays that can impact 

getting capabilities to the warfighter.

The Air Force’s restructured strategy does not fully follow the evolutionary, 

knowledge-based approach espoused by best practices and DOD’s revised 

acquisition guidance. A knowledge-based approach encourages managers 

to attain the necessary product knowledge at key points to support 

investment decisions, ensuring, for example, that technologies are mature 

before starting an acquisition program and that the design is stable before 

beginning manufacturing. This approach includes incremental or 

evolutionary development, which sets up a more manageable environment 

for attaining and applying knowledge and is intended to increase the 

chances of delivering a quality weapon system to the warfighter quickly 

and cost effectively. While the original acquisition strategy more closely 

adhered to this approach, the restructured strategy has caused gaps in 

knowledge about technology, design, and manufacturing at major 
Page 4 GAO-05-6 Global Hawk Acquisition

investment decision points. These actions changed the underpinnings of 

the program’s original business case and increased the likelihood of future 

cost increases and schedule delays in delivering the capabilities expected 

by the warfighter. Air Force and contractor officials have established a 

wide range of management controls to help mitigate risks. While some of 

these controls may increase visibility into risks, the history of successful 

product development programs has shown that risk mitigation plans do not 

work optimally unless they are based on knowledge appropriate for 

decisions that must be made at critical junctures.

We are recommending that the Secretary of Defense direct the Air Force to 

revisit the decision to concurrently develop and produce the new Global 

Hawk design. The Secretary should direct the Air Force to conduct and 

present a new business case that defines the warfighter needs that can be 

accommodated given current available resources of technology, 

engineering capability, time, and money. To keep risks from increasing 

beyond current levels in this program, we also recommend the Secretary 

delay further procurement of the new Global Hawk, other than units 

needed for testing, until a new business case is completed that reduces risk 

and justifies further investments on a knowledge-based acquisition 

strategy. DOD disagreed with both recommendations, stating that risks are 

being effectively managed and that our approach would take more time and 

more money to implement. We continue to believe that our 

recommendations would improve congressional and DOD oversight, 

reduce program risks, and save time and money over the life of the 

program through a more rigorous and comprehensive application of 

knowledge-based practices.

Background The Global Hawk unmanned aerial vehicle system is designed to support 

warfighting and peacekeeping missions by providing decision makers with 

up-to-date information about potential adversaries’ locations, resources, 

and personnel. Operators on the ground can change Global Hawk’s 

navigation and direct the onboard sensors to survey a geographic area the 

size of Illinois within a 24-hour cycle. As a high-altitude, long-endurance 

aircraft, Global Hawk was originally designed to reach an altitude of 

65,000 feet and fly for up to 35 hours.

Global Hawk began in 1994 as an acquisition concept technology 

demonstration program, managed first by the Defense Advanced Research 

Projects Agency and, since 1998, by the Air Force. Seven demonstrator 

aircraft were eventually produced; three have since been destroyed in 
Page 5 GAO-05-6 Global Hawk Acquisition

mishaps. The demonstrator models logged several thousand-flight hours 

and effectively supported combat operations in Afghanistan and Iraq. 

The system passed a military usefulness assessment, completed several 

demonstrations and other tests, and DOD judged it a success. However, 

testing identified that significant improvements in reliability, sensor 

performance, and communications were needed before producing 

operationally effective and suitable systems.

In March 2001, DOD approved the Global Hawk for a combined start of 

system development and low-rate initial production of six air vehicles 

based on the successful demonstrations and operational deployments of 

demonstrator aircraft. The Air Force planned to slowly develop more 

advanced capabilities and acquire 63 air vehicles. This model, now called 

the RQ-4A, is shown in figure 1.

Figure 1: Global Hawk RQ-4A

Source: Northrup Grumman.
Page 6 GAO-05-6 Global Hawk Acquisition

In March 2002, DOD restructured the acquisition strategy to include a 

second Global Hawk model, the RQ-4B. The new strategy includes 51 air 

vehicles, 10 ground stations, multiple intelligence sensors, support 

equipment, and facilities at a cost of $6.3 billion. Of the 51 air vehicles 

to be purchased, 7 are RQ-4As and 44 are RQ-4Bs. Separately, the Navy is 

procuring 2 RQ-4As and a ground station for about $300 million (including 

development costs) to evaluate the vehicles’ potential for the Broad Area 

Maritime Surveillance Program. In December 2002, DOD restructured 

the program again. Instead of buying all RQ-4Bs with multiple 

intelligence capability, the RQ-4Bs will now have a mix of multimission and 

single-mission capabilities. The two restructurings also increased low-rate 

initial production quantities to 19 (recently increased to 20) air vehicles: 

7 RQ-4As and 12 (now 13) RQ-4Bs.

Differences between the 

Two Global Hawk Models

The RQ-4A and the RQ-4B differ significantly. The new RQ-4B model is 

intended to have 50 percent greater payload capacity, a longer fuselage and 

longer wing span and will be heavier than the A model. DOD considered 

these changes necessary to carry new advanced sensor payloads and to 

provide multi-intelligence capabilities on a single RQ-4B. Even though the 

RQ-4B is bigger and heavier, it will use the same engine as the RQ-4A. 

Table 1 shows the key differences in the two models.

Table 1: Key Characteristics of Global Hawk RQ-4A and RQ-4B Models

Sources: Northrop Grumman (data); GAO (analysis).

Key characteristics RQ-4A RQ-4B

Payload capacity 2,000 pounds 3,000 pounds

Take-off weight 26,750 pounds 32,250 pounds

Wingspan 116.2 feet 130.9 feet

Fuselage length 44.4 feet 47.6 feet

Endurance 31 hours 33 hours

Time at 60,000 feet 14 hours 4 hours

Average speed at 60,000 feet 340 knots 310 knots

Approximate range 10,000 nautical miles 10,000 nautical miles
Page 7 GAO-05-6 Global Hawk Acquisition

In addition to the differences shown in table 1, the RQ-4B includes new 

requirements for advanced sensors payloads,4

 enhancements to 

communications and ground stations, a new multiplatform common data 

link, and an open systems architecture. The new design will use more 

advanced technologies (such as lithium batteries and electric brakes), will 

require a larger power-generating capability, and will incorporate new 

landing gears that fold into the wing. Also, the design changes require new 

manufacturing processes and investments in new production tooling—the 

factory equipment and manufacturing items used to build large quantities 

of major weapon systems, such as Global Hawk.

Restructured Global 

Hawk Program 

Attempts to Do More 

in Less Time

Global Hawk’s restructuring has impacted the acquisition program in a 

number of significant ways: the time span for funding has been compressed 

into roughly half the time and the overall funding amount has increased; 

concurrent development and production is causing the Air Force to invest 

in almost half the total fleet of the new and improved Global Hawk vehicle 

before a production model has proven that it will work as intended; and 

development costs have tripled because of the need to develop a new and 

improved vehicle. In addition, the program has deferred some capabilities 

and incurred delays that could affect the Air Force’s ability to deliver 

Global Hawk to the warfighter.

Annual Funding Needs 

Are Higher under 

Restructured Program

The restructured program requires greater up-front investment, a faster 

ramp-up in funding, and a larger total budget. The development period was 

extended from 7 years to 12 years, and development funding increased 

significantly to develop the RQ-4B and to integrate advanced sensor and 

communication technologies. Procurement is now concentrated into 

11 years instead of the 20 years of relatively level procurement set out in 

the original plan. The restructuring triples Global Hawk’s budgetary 

requirements in some years. Figure 2 illustrates the restructuring’s 

compression of the program and impact on annual funding requirements.

4

 In addition to enhancements to existing imagery sensors, the RQ-4B will eventually 

incorporate the Airborne Signals Intelligence Payload and the MultiPlatform Radar 

Technology Insertion Program.
Page 8 GAO-05-6 Global Hawk Acquisition

Figure 2: Global Hawk’s Annual Funding Requirements

Funding, as of December 2003, after restructuring (in millions of then-year dollars)

Sources: Air Force (data); GAO (analysis).

Production

Development

Military construction

20012002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

20182019

2020

Years

800

700

600

500

400

300

200

100

0

Funding, as of September 2001, before restructuring (in millions of then-year dollars)

20012002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

Years

800

700

600

500

400

300

200

100

0
Page 9 GAO-05-6 Global Hawk Acquisition

Compared with the original plan, the restructured plan has much higher 

annual funding requirements, placing more budgeted funds at risk of not 

being fully funded when competing for the defense dollar. In their 

respective peak years of budget requirements, the original plan would have 

required $353 million (fiscal year 2010), while the restructured plan expects 

to request $781 million (fiscal year 2007). The upcoming fiscal year 2006 

requirement is currently about $750 million, three times higher than the 

original plan for that same fiscal year. Cumulatively, the restructured plan 

requires $6.3 billion to be completed in fiscal year 2012, whereas the 

original plan would only have needed $3.4 billion by that year.

Restructured Program 

Increased Concurrency 

between Development 

and Production

Significant concurrency now exists between development and production 

that covers the period from fiscal years 2004 to 2010. The Air Force now 

plans to invest in almost half of the total RQ-4B fleet before a production 

model is flight-tested and operational evaluations are completed to show 

that the air vehicle design works as required. Full-rate production will 

begin before the airborne signals intelligence and multiplatform radar 

complete development and are flight-tested to prove the integrated system 

will work as intended. The primary reason for building the RQ-4B model 

was to integrate and carry the advanced sensors to provide added 

capability to the warfighter. Additionally, schedule delays have already 

occurred in the restructured plan that will continue to add pressure in 

the program.

Collectively, the actions to restructure the program have materially 

changed the underpinnings in the original business case decision 

developed to justify the start of system development and low-rate 

production. The business case should provide sufficient evidence that 

resources are available to meet warfighter needs. This case would include 

technology and design demonstrations that added confidence that the 

integrated product can be developed within time and money constraints. 

The original plan was to first acquire basic RQ-4A systems very similar to 

the demonstrators and then slowly and incrementally develop and acquire 

systems with more advanced sensor capabilities while using the same air 

vehicle. This strategy incorporated an evolutionary approach in that a basic 

capability was to be produced in a first block of aircraft and a second, more 

advanced block was to be acquired once the new technologies were 

mature. Each block had separate decision points and testing plans and 

significant risk was removed from the program because the demonstrators 

had been built, tested, and extensively flown (and later used successfully in 

actual combat operations in Afghanistan and Iraq). While testing showed it 
Page 10 GAO-05-6 Global Hawk Acquisition

needed some improvements, the RQ-4A was significantly more mature and 

proven than the RQ-4B model to begin production.

Figure 3 illustrates the significantly greater concurrency of development 

and production activities resulting from the program’s restructuring 

compared with the original plan. Historically, programs with high degrees 

of concurrency are at greater risk of cost, schedule, and performance 

problems than programs with less overlap of development and production. 

The original acquisition strategy planned to complete most development 

testing prior to beginning production, thereby taking advantage of product 

knowledge. The restructured program added the new RQ-4B model, 

substantially increased low-rate production quantities, and established 

highly concurrent development and production cycles to acquire and test 

several different RQ-4B configurations over the life of the program. The Air 

Force plans to invest in 20 RQ-4Bs before completion of initial operational 

test and evaluation. The reason for designing a larger and heavier Global 

Hawk was to satisfy warfighter needs for the new advanced sensors. 

However, integration and operational testing of the advanced sensors on 

the fully configured air vehicle are not scheduled to be completed and 

reported on until fiscal year 2009 for the advanced signal intelligence 

sensor and fiscal year 2011 for the multiplatform radar. By this time, the 

entire RQ-4B fleet will already be produced or on order.
Page 11 GAO-05-6 Global Hawk Acquisition

Figure 3: Restructured 2004 Plan Is Highly Concurrent Compared with Original Global Hawk Plan

Note: In this figure, development includes both technology and system development.

Original 2001 plan (in fiscal years)

2001 ’02 ’03 ’04 ’05 ’06 ’07 ’08 ’09 ’10 ’11 ’12 ’13 ’14 ’15 ’16 ’17 ’18 ’19 ’20 2021 Key attributes

12 air vehicles with basic 

imagery sensors

25 air vehicles with advanced 

imagery sensors and 26 air 

vehicles with signals 

intelligence

Total air vehicles: 63

Basic

RQ-4A

Advanced

RQ-4A

Develop.

Production

Development

Production

Sources: Air Force (data); GAO (analysis).

Restructured 2004 plan (in fiscal years)

Key attributes

Basic

RQ-4A

Advanced

RQ-4B

(phase 1)

Advanced

RQ-4B

(phase 2)

Production

Development

Production

Advanced

RQ-4B

(phase 3)

Development

Production

Advanced

RQ-4B

(phase 4)

Development

Production

Development

Production

7 air vehicles with basic 

imagery sensors

Total air vehicles: 51

12 air vehicles with advanced 

multiplatform radar 

technology

15 air vehicles with improved 

sensors and advanced 

signals intelligence

8 air vehicles with improved 

sensors and improved signals 

intelligence to be retrofitted 

later with advanced signals 

intelligence

9 air vehicles with improved 

imagery sensors and limited 

signals intelligence

2001 ’02 ’03 ’04 ’05 ’06 ’07 ’08 ’09 ’10 ’11 ’12 ’13 ’14 ’15 ’16 ’17 ’18 ’19 ’20 2021

Develop.
Page 12 GAO-05-6 Global Hawk Acquisition

Restructured Program 

Added Requirements 

and Increased Costs

Global Hawk’s development cost estimates have increased almost 

threefold, from $906.2 million in March 2001 to about $2.6 billion in 

March 2004, mostly due to the requirement for the new RQ-4B’s inclusion in 

the program. Total program costs have continued to increase, including an 

increase of $466 million since March 2003. The program acquisition unit 

cost increased 44 percent since program start, from $85.6 million to 

$123.2 million. Increasing costs for Global Hawk raises affordability issues 

and questions about employing the vehicle in medium- and high-threat 

environments because of its high replacement costs and limited numbers. 

Total procurement cost estimates decreased from program start due to 

the cut in quantities from 63 to 51 and inflation savings resulting from 

compressing the program and cutting 9 years of future procurement 

activities. Table 2 shows how costs have changed since March 2001 

in millions of then-year dollars.

Table 2: Global Hawk Program’s Cost, Quantity, and Unit Costs

Sources: Air Force (data); GAO (analysis).

a

All costs are expressed in millions of then-year dollars, which include inflation and represent the 

Air Force’s budget plans.

b

Total program unit cost is calculated by dividing the total cost of development, procurement, and 

system-specific military construction for the acquisition program by the quantity of air vehicles to be 

produced. Procurement unit cost is the total amount for procurement divided by the number of air 

vehicles to be procured. It does not include costs for development and military construction.

March 2001

(original plan)

March 2002

(1st restructuring)

March 2003

(2nd restructuring)

March 2004

(status this year)

Total costa

Development $906.2 $2,311.0 $2,395.6 $2,587.9

Procurement 4,459.8 4,388.9 3,278.5 3,552.2

Military construction 28.0 146.7 140.8 140.8

Total program $5,394.0 $6,846.6 $5,814.9 $6,280.9

Quantity

Air vehicles 63 51 51 51

Ground stations 14 10 10 10

Unit costsa,b

Total program $85.6 $134.2 $114.0 $123.2

Procurement only $70.8 $86.0 $64.2 $69.6
Page 13 GAO-05-6 Global Hawk Acquisition

The following factors caused the Global Hawk program’s cost estimates to 

change between 2001 and 2004:

• March 2001 cost estimate: Based on the original acquisition strategy 

to slowly and incrementally develop and acquire improved versions of 

the demonstrator model. The RQ-4B model was not yet part of the 

acquisition strategy.

• March 2002 cost estimate: Reflects changes for the first restructuring 

of the program, which introduced the RQ-4B. Development costs 

increased significantly because of plans to quickly build advanced 

capabilities into the RQ-4B. While the quantity of air vehicles—the 

RQ-4A and RQ-4B models—and ground stations decreased because of 

revised user requirements, total procurement costs increased because 

of the higher cost for the RQ-4Bs and the plan at that time to equip all 

the larger platforms with multi-intelligence mission capabilities.

• March 2003 cost estimate: Reflects a second restructuring for 

affordability reasons. In December 2002, DOD officials decided to 

switch from all multimission capabilities to a mix of multimission 

and single-mission RQ-4Bs. This switch lowered procurement costs by 

decreasing the required number of sensors.

• March 2004 cost estimate: Between March 2003 and March 2004, 

total program cost increased by $466 million, and officials added 

another 18 months to the development program to accomplish 

requirements deferred from prior years and to accommodate new 

requirements. Development costs increased to cover the extended 

schedule and additional requirements. Procurement costs increased 

primarily because of higher costs for structural components and for 

labor to build the RQ-4B.

Restructured Program 

Has Created Other 

New Challenges

Space, weight, and power constraints of the RQ-4B limit what capabilities 

can be included now or added in the future. Some capabilities have already 

been eliminated or deferred to later years. For example, the warfighter 

wanted a defensive subsystem for Global Hawk, but development has been 

delayed and may be dropped because of weight limitations in the air 

vehicle, already at or near capacity with some of the new advanced sensor 

payloads. Also, the RQ-4B configured with the airborne signals intelligence 

payload is projected to have no capacity for future growth because this 

payload weighs more than allocated in the design of the air vehicle. 
Page 14 GAO-05-6 Global Hawk Acquisition

Other development tasks have similarly been delayed or pushed out 

beyond the budget years, including efforts related to demonstrating that 

Global Hawk can operate in areas with extreme temperatures.

The Air Force’s overall acquisition approach to add new technologies 

whenever they are deemed ready was designed to allow flexibility in 

responding to changes in priorities and new requirements. However, 

Global Hawk’s vehicle limitations and changing requirements have 

increased development challenges. For example, despite the space, weight, 

and power limitations of the RQ-4B, Air Force officials stated that Global 

Hawk users and other DOD officials continue to identify potential future 

technologies and capabilities for possible incorporation into Global Hawk. 

Absent major downsizing of the advanced sensors or other payloads, the 

Air Force will need to consider dedicating the RQ-4B to an increasing 

number of single and specific—rather than multi-intelligence—missions, if 

the goal is to utilize new and unproven emerging technologies not currently 

part of the Global Hawk plan.

Delays in Key Events Since 

Restructuring Can Impact 

Delivery of New Capability

The new schedule for some key events and activities has slipped because 

of programmatic, budget, or external issues. Air Force and contractor 

officials say that a significant contributor to schedule delays was the 

episodic deployment of Global Hawk’s earlier model in Afghanistan and 

Iraq. The Global Hawk system—including considerable numbers of Air 

Force and contractor personnel, ground stations, and supporting 

equipment—has been used to support combat operations and is subject to 

future deployment orders.

Some examples of program events that have been delayed and others 

whose future schedules have slipped include:

• government acceptance of the second RQ-4A production aircraft due to 

quality and performance problems identified during tests;

• delivery of the equipment and support needed to begin initial operations 

at the Global Hawk’s home base, Beale Air Force Base in California;

• the operational assessment of the RQ-4A;

• completion of the first phase of combined developmental and 

operational testing of Global Hawk;
Page 15 GAO-05-6 Global Hawk Acquisition

• acquisition of production tooling, establishing manufacturing processes, 

and delivering parts needed for production;

• delivery schedules projected for RQ-4B air vehicles; and

• the expected start of initial operational test and evaluation to support 

the full-rate production decision.

Delays and deficiencies in scheduled development testing could 

compromise upcoming decisions in the program. According to test officials 

in the Office of the Secretary of Defense, the first of five phases of Global 

Hawk’s combined development and operational testing is not as robust as 

originally planned and is taking significantly longer than expected. As of 

July 2004, only about 10 percent of the required flight test points had been 

completed and nearly 70 percent of the remaining test points were either 

on hold or not fully defined. The approved test plan required this testing to 

be completed by September 2004, but testing officials do not expect it to be 

completed until March 2005. Test delays are occurring due to late delivery 

of key subsystems, lack of resources, deployments in support of the global 

war on terrorism, other program priorities, and unexpected testing 

problems. Test officials told us that the lack of quality test data is 

hampering their ability to provide meaningful oversight.

The results from this first phase of development testing were to be used in 

the operational assessment of the first two production RQ-4A aircraft 

starting in September 2004 to assess the Global Hawk’s mission readiness 

and suitability. Because of phase one delays, the start of the assessment has 

slipped until at least March 2005. Test officials believe further delays are 

likely because of other higher priorities, including the start-up activities at 

Beale Air Force Base. At this time, a firm date for the testing has not been 

scheduled and the unapproved test plan still lacks the necessary details to 

ensure effective testing. Test officials believe the operational assessment is 

in jeopardy of being cancelled or cut back in order to start the dedicated 

initial operational test and evaluation on time. The officials say that 

eliminating the operational assessment, or reducing its scope, would add 

risk to the program. Entering the next phase involves testing the new, 

larger RQ-4B aircraft and advanced sensor payloads, and, without having 

the assurances the production aircraft are mission-ready, additional tests 

will likely be required.
Page 16 GAO-05-6 Global Hawk Acquisition

Global Hawk 

Program’s Current 

Management Approach 

Sets Stage for 

Additional Risks

In attempting to get advanced capabilities to the warfighter sooner, the 

Air Force’s restructured acquisition strategy for the Global Hawk program 

does not fully follow best practices and DOD acquisition guidance for an 

evolutionary, knowledge-based acquisition process. DOD recently rewrote 

its acquisition policy specifically to encourage acquisitions to develop and 

deliver increased capability to the warfighter incrementally (or on an 

evolutionary basis), only when appropriate knowledge concerning 

technology, design, and manufacturing has been attained. Compared with 

the original strategy, the new Global Hawk acquisition strategy has yielded 

less product knowledge in each of these areas, thereby raising the 

likelihood of future negative impacts on cost, schedule, and performance. 

Air Force and contractor officials acknowledge that—with its highly 

compressed and concurrent schedule—the program is risky and presents 

major management challenges. The Air Force has established management 

controls and processes intended to mitigate risks; however, without a 

disciplined process to capture and base investment decisions on key 

technology, design, and manufacturing knowledge, the controls are less 

robust and the risks remain high.

Restructured Acquisition 

Strategy Does Not Fully 

Capture Product Knowledge 

at Key Decision Points

By approving the start of system development and low-rate production at 

the same time, Global Hawk’s restructured acquisition strategy skipped the 

critical decision points that require the capture of key product knowledge 

used to inform decisions to move forward in an acquisition program. 

Skipping the necessary steps to capture technology, design, and 

manufacturing knowledge has added risk to the program. The Air Force 

would have captured more knowledge under the original March 2001 

strategy, which more closely followed the knowledge-based approach. 

At that time, the plan was to acquire basic air vehicles and ground systems 

very similar to the demonstrators that had already been built, extensively 

flown, and (later) used in combat. The Air Force then planned to upgrade 

sensor and performance capabilities for the next production lot as the 

technologies matured while retaining the same airframe. Since the decision 

to start the program, additional information and experience have closed 

some of the gaps, but a substantial lack of knowledge continues to add risk 

to the RQ-4B acquisition.
Page 17 GAO-05-6 Global Hawk Acquisition

GAO has a body of work focused on best practices in product development 

and weapon systems acquisition.5

 We have found that when program 

managers capture key product knowledge at three critical knowledge 

points during a major acquisition, the probability of meeting expected 

performance within cost and schedule objectives increases. Each of the 

points builds on previously attained knowledge. The acquired knowledge is 

used to identify and reduce any risks before moving a weapon system to 

the next stage of development. This approach to developing new 

products—commercial and defense—has been shown over time to 

continually produce successful outcomes in terms of cost, schedule, 

and performance.

In recent years, DOD revised its acquisition policy to embrace an 

evolutionary and knowledge-based approach, which we believe provides a 

sound framework for the acquisition of major weapon systems. This policy 

covers most of DOD’s major acquisition programs. As noted in our 

November 2003 report,6

 this revised policy is a step in the right direction. 

The acquisition policy states that program managers shall provide 

knowledge about the key aspects of the system at key decision points in the 

acquisition process7

 and an evolutionary or incremental development 

approach should be used to establish a more manageable environment for 

attaining and applying knowledge. The customer may not get the ultimate 

capability right away, but the initial product is available sooner and at a 

lower cost. The policy adopts the essence of the following points from the 

knowledge-based approach:

• Knowledge point 1: Should occur when the acquisition program is 

scheduled to start, when the customer’s requirements are clearly 

defined, and resources—proven technology, engineering capability, 

5

 GAO, Defense Acquisitions: Assessments of Major Weapon Programs, GAO-04-248

(Washington, D.C.: Mar. 31, 2004). This report includes an assessment of the Global Hawk 

program against the knowledge-based approach. Other recent reports discussing best 

practices include GAO, Best Practices: Capturing Design and Manufacturing Knowledge 

Early Improves Acquisition Outcomes, GAO-02-701 (Washington, D.C.: July 15, 2002) 

and Defense Acquisitions: DOD Faces Challenges in Implementing Best Practices, 

GAO-02-469T (Washington, D.C.: Feb. 27, 2002).

6

 GAO, Defense Acquisitions: DOD’s Revised Policy Emphasizes Best Practices, but More 

Controls Are Needed, GAO-04-53 (Washington, D.C.: Nov. 10, 2003).

7

 For example, the policy states that unless some other factor is overriding in its impact, 

the maturity of the technology shall determine the path to be followed by the program in 

entering the system development phase of the acquisition cycle.
Page 18 GAO-05-6 Global Hawk Acquisition

time, and money—exist to satisfy them. This match should support the 

business case for starting system development and demonstration. 

Technology should be mature before starting a program, and, therefore, 

the technology development phase of an acquisition should be separate 

from the system development phase.

• Knowledge point 2: Should occur at the design readiness review, 

about halfway through the system development phase, when the 

product’s design is determined to be capable of meeting product 

requirements—the design is stable and ready to begin initial 

manufacturing of prototypes.

• Knowledge point 3: Should occur when managers commit to starting 

production, when information is available to determine that a reliable 

product can be produced repeatedly within established cost, schedule, 

and manufacturing quality targets.

Figure 4 shows a generalized depiction of DOD’s acquisition policy, where 

DOD’s key milestones are anchored along a typical program’s acquisition 

path and where the three knowledge points from the knowledge-based 

approach fit along this path. Also shown in figure 4 is how the Global Hawk 

program overlaps technology and system development and begins 

production before the necessary knowledge is achieved.
Page 19 GAO-05-6 Global Hawk Acquisition

Figure 4: Global Hawk Program Is Not Fully Aligned with DOD’s Acquisition Policy and Knowledge-Based Approach

Global Hawk’s new strategy approved initial production of the improved 

RQ-4B well in advance of completing technology maturation and approved 

developing and integrating the vehicle’s design with the various sensor 

payloads desired by the warfighter. Furthermore, low-rate production was 

approved without ensuring the quality and reliability of manufacturing 

processes. This approach added significant risk in that sensor technologies 

and final design may not meet the space, weight, and power limitations of 

the RQ-4B, which is in low-rate production, and may not satisfy the 

Sources: DOD and Air Force (data); GAO (analysis).

Where key decision points are along acquisition path for DOD’s policy compared with knowledge-based approach

Where concurrency appears along Global Hawk’s acquisition path

Start of technology

development

Program

start

Design readiness

review

Program

start

Production

decision

All three knowledge points reduced

to one point; Global Hawk program

proceeds without necessary knowledge

Knowledge

point 1

Knowledge

point 2

Knowledge

point 3

Concept refinement and

technology development

System development and

demonstration Production

Initial technology development

for RQ-4A, the demonstrator model

Technology and system development

for RQ-4B, the advanced model

Production of RQ-4B

Concurrency

DOD’s key milestones

Knowledge-based approach’s 

key points
Page 20 GAO-05-6 Global Hawk Acquisition

warfighter’s requirements. By not closing knowledge gaps in the integrated 

product design (air vehicle, sensor payloads, and data links) needed to 

meet requirements, there is increased risk that sensor development 

schedules may need to be extended to achieve form, fit, and function for an 

integrated Global Hawk system. Otherwise, the program office may have to 

go back to the warfighter and further negotiate requirements. Table 3 

compares the product knowledge available to support key decision points 

under the original plan in March 2001 with the knowledge obtained at the 

start of RQ-4B production in July 2004. A black dot indicates product 

knowledge meets best practice standards from knowledge-based approach.

Table 3: How Global Hawk Product Knowledge Compares with Three Critical Points in the Knowledge-Based Approach

Sources: Air Force (data); GAO (analysis).

Note: A black dot (•) indicates product knowledge meets best practice standards from knowledgebased approach.

a

75 percent of drawings released at design readiness review in April 2004.

b

System representative prototype will not be built. Since the basic design evolved from RQ-4A, the Air 

Force and contractor are conducting modeling efforts and component tests, such as wind tunnel 

testing of the new wing, to validate that the RQ-4B air vehicle design should meet requirements.

Global Hawk program status:

Date March 2001 July 2004

Status At combined system development and 

limited production decision for RQ-4A

At start of RQ-4B production for basic 

RQ-4B air vehicle design with limited 

signals intelligence

Three critical points of knowledge-based approach and best practice standards:

Knowledge point 1: Technologies needed to meet essential product requirements have been demonstrated to work in their intended 

environment, and the producer has completed a preliminary design of the product.

Technologies matured to high readiness levels •

Preliminary design established • •

Knowledge point 2: Design is stable and has been demonstrated through prototype testing. Ninety percent of engineering drawings 

releasable to manufacturing organizations.

90 percent of engineering drawings released • a

Prototype demonstration that design should meet 

requirements

• b

Reliability targets and growth curve established

Knowledge point 3: Product is ready to be manufactured within cost, schedule, and quality targets. All key manufacturing processes 

have come under statistical process control and product reliability has been demonstrated.

Fully integrated system representative prototype 

demonstrated to work in operational environment

•

Critical processes capable and in statistical control

Reliability demonstrated 
Page 21 GAO-05-6 Global Hawk Acquisition

The table shows that the level of product knowledge approached best 

practice standards when the decision was made in March 2001 to start 

system development and low-rate production of the RQ-4A. The program’s 

restructurings in 2002, however, created substantial gaps in technology, 

design, and manufacturing knowledge that have not yet been closed by the 

start of RQ-4B production. Lack of product knowledge increases risks of 

poor cost, schedule, and performance outcomes. Appendix III includes a 

more detailed discussion of knowledge gaps at each knowledge point. 

Following are brief examples of knowledge gaps as they relate to each of 

the three critical knowledge points.

Technology maturity: Using best practices, at the start of system 

development, a program’s critical technologies should be in the form, fit, 

and function needed for the intended product and should be demonstrated 

in a realistic environment. The RQ-4B development program is struggling to 

meet these criteria for several of its most critical technologies. Nearly 

2 years after development began, the technologies required for the RQ-4B 

to perform its operational mission including enhanced imaging sensors, 

signals intelligence, multiplatform radar, and open system architecture are 

immature, basically at a functional rather than form or fit configuration. 

For example, the airborne signals intelligence payload and multiplatform 

radar technology insertion program are still in development under separate 

Air Force programs. These subsystems are key to providing the advanced 

intelligence, surveillance, and reconnaissance capabilities for which the 

RQ-4B is being developed. At the time of our review, neither of these 

technologies had been demonstrated in an operational environment using a 

system prototype. Air Force officials expect them to be mature by the time 

they begin buying sensors to incorporate them into the Global Hawk 

production line in fiscal years 2008 and 2009. However, by this time most of 

the air vehicles will have already been bought. Also, operational testing to 

evaluate performance in a realistic operating environment is not scheduled 

until late fiscal year 2008 for the signals intelligence sensor and late 2010 

for the radar. Nevertheless, the Air Force continues to build the RQ-4B 

platform lacking solid assurance that these critical subsystems will work 

as planned.

Design maturity: The program had completed 75 percent of RQ-4B model 

drawings by the design readiness review in comparison with the 90 percent 

completion standard for best practices. While the Air Force anticipated the 

design and experience on the RQ-4A would add assurances and speed 

efforts to mature the new RQ-4B design, the two vehicles ultimately had 

only about 10 percent commonality. While drawings completed were 
Page 22 GAO-05-6 Global Hawk Acquisition

approaching best practice standards, the Air Force did not build a 

prototype of the RQ-4B design to demonstrate a stable design. 

Demonstration of the design is a key factor in ensuring a stable design. 

The Air Force had not established a reliability growth goal or plan and had 

not identified critical manufacturing processes, both essential to the next 

phase of production and needed to ensure quality and cost targets can 

be met.

Production maturity: Officials have started to identify the critical 

manufacturing processes for the RQ-4B but do not intend to collect and use 

statistical process control data to ensure the manufacturing could deliver 

quality products. The new RQ-4B requires new manufacturing processes 

because of major differences from the RQ-4A. In addition, Officials from 

the program office, the prime contractor, and the Defense Contract 

Management Agency continue to identify problems and concerns about the 

performance and quality of work by several key subcontractors, including 

those producing the wing, the advanced sensor suite, and the vertical tail 

and aft fuselage parts. This latter subcontractor is new to large-scale 

manufacturing using advanced composite materials and has experienced 

significant start-up and quality problems. According to best practices, the 

subcontractor’s critical processes must be demonstrated to ensure good 

quality and limit rework. The prime contractor and DOD sent special teams 

of advisors to help develop the firm’s manufacturing processes and to train 

employees. Creating another gap in production maturity, a fully integrated 

system representative prototype was not tested before starting production 

and will not have been demonstrated before full-rate production, scheduled 

in 2007. By then, 45 percent of the RQ-4B planned quantities will be 

under contract.

Joint Efforts Will Help 

Manage Risk in the 

Global Hawk Program

Air Force and contractor officials agree that the restructured program 

significantly increased program and technical risks. They acknowledge that 

the use of the approach to insert technology periodically affects all aspects 

of the program, making it more challenging to manage functional areas, 

including logistics support, contracting, program integration, and testing. 

To better manage the risks and challenges created by this acquisition 

approach and environment, the Global Hawk management team provided 

the following as examples of actions they are taking

• better teaming practices between the government and contractor to 

manage the program at all levels;
Page 23 GAO-05-6 Global Hawk Acquisition

• better controls for the release of funds on both development and 

production contracts;

• allocation of higher amounts of management reserve funding during 

contract performance;

• use of a “buy to budget” concept that limits activity in the program to a 

ceiling amount of funds planned for the total program; and

• use of a risk management database to focus the attention of 

management on the most critical risks facing the program.

These are all management practices that can be used to manage any 

product development program and will likely identify and help manage 

risks in the Global Hawk program. Nevertheless, using a knowledge-based 

approach that captures critical knowledge at key junctures in a program 

has been shown time and again in both commercial and defense acquisition 

programs to consistently produce successful outcomes—cost, schedule, 

quality, and performance.

Conclusions In March 2001, DOD approved the start of development and production for 

Global Hawk on the basis of a business case that matched requirements 

with resources—technologies, engineering capabilities, time, and funding. 

The first increment of Global Hawk was based on mature technologies and 

a design proven to meet the warfighter’s need through actual combat use of 

the technology demonstrator. The plan included a reasonable funding 

profile and embraced a knowledge-based acquisition strategy that 

completed development before entering production. The plan included 

future improvements to the baseline capability as technologies and funding 

became available. By December 2002, the Air Force had dramatically 

changed the Global Hawk’s acquisition plan and the knowledge-based 

foundation for the earlier decision to proceed into development and 

production. This change created large gaps between Global Hawk’s 

requirements and the resources available to meet them. The new plan 

required a new, larger, and heavier air vehicle with only 10 percent 

commonality with the previous proven design; increased development 

time; and accelerated production time, creating significant concurrency 

between development and production. To accommodate the changes, the 

plan calls for twice the annual funding amounts in peak years over the old 

plan. Overall, the new plan has increased risks significantly. Subsequent 

reviews by DOD have acknowledged the changes in the program have 
Page 24 GAO-05-6 Global Hawk Acquisition

increased uncertainty. The new design has not been demonstrated to work 

using a prototype model; technologies to support the advanced sensor 

payloads that drove the need for a new Global Hawk design are still 

immature; and the Air Force will be requesting about $750 million in 

funding next year for the program. Yet, the Air Force has awarded a 

contract to start the production of the new, larger Global Hawk B model 

with the hope that simulations and analysis will be sufficient to allow 

decision makers to manage risk. The history of DOD managed programs 

suggests otherwise.

Recommendations for 

Executive Action

To decrease risks of poor outcomes and to increase the chances of 

delivering required warfighter capabilities with the funds available, we are 

making recommendations to the Secretary of Defense to take the following 

two actions

• direct the Air Force to revisit the decision to begin concurrent 

development and production of the Global Hawk B design and direct the 

Air Force to create and present a new business case that defines the 

warfighter’s needs that can be accommodated given current available 

resources of technology, engineering capability, time, and money, and

• delay further procurement of the Global Hawk B, other than units 

needed for testing, until a new business case is completed that reduces 

risk and justifies further investments based on a knowledge-based 

acquisition strategy.

Agency Comments and 

Our Evaluation

DOD provided us with written comments on a draft of this report. The 

comments appear in appendix II. DOD stated that it did not concur with 

our two recommendations. Separately, DOD provided one technical 

comment that we incorporated in this report to more accurately 

characterize the issue of affordability and use of Global Hawks in threat 

conditions.

Regarding our first recommendation on completing a new business case to 

justify and guide concurrent development and production of the RQ-4B 

model, DOD stated its belief that the Global Hawk’s acquisition strategy 

balances acquisition risks with the department’s demands to rapidly field 

new capabilities to the warfighter, thereby obviating the need for a new 

business case. Furthermore, by following what officials call an 
Page 25 GAO-05-6 Global Hawk Acquisition

evolutionary development process, DOD said it is providing 

transformational warfighting capabilities to ongoing military operations 

without disrupting Global Hawk’s current development and production 

activities. DOD said it is effectively managing risk with the help of regular 

oversight meetings and by requiring monthly and quarterly activity reports.

We continue to believe that a new business case is needed to support 

further investments and to improve oversight by Congress and DOD 

decision makers. The program today is much different than the one 

supported by the original business case. The Air Force started with an 

advanced concept technology demonstration program that proved the 

capability of a smaller and lighter Global Hawk air vehicle. Use of this 

vehicle on numerous occasions in actual combat situations has saved lives, 

according to Air Force and contractor officials. However, this is not the 

vehicle that the Air Force now plans to produce. Instead, the Air Force 

dramatically changed the acquisition strategy for the Global Hawk program 

and is not gaining some key knowledge before production. The Air Force 

plans to concurrently design and produce a new Global Hawk air vehicle 

that is significantly larger and heavier than the earlier version used in 

combat. The larger air vehicle is intended to accommodate new, heavier, 

and larger sensors that will not be available until the 2008 to 2009 time 

frame. In implementing the restructured strategy, the Air Force is not fully 

following a knowledge-based approach for developing the RQ-4B Global 

Hawk as called for by best practices and DOD’s new defense acquisition 

guidance. The new guidance clearly states that knowledge reduces risks, 

and we agree.

While the Air Force believes it can manage the risk of a concurrent 

development and production program by holding regular meetings with 

acquisition executives and by issuing management reports, DOD’s own 

experience has shown this to be risky and a factor that led DOD to change 

its acquisition policy to a knowledge-based approach. History has shown 

concurrency usually delays the delivery of a needed capability and results 

in higher costs. From March 2003 to March 2004, estimated program costs 

have increased by $466 million, and the sensors and the new air vehicle are 

still being developed. Stepping back from this rush to produce the new air 

vehicle and establishing a new business case designed to capture key 

product knowledge before costly investments in production would better 

inform DOD decision makers and Congress about what is feasible with 

available technology and dollar resources to meet warfighter needs and to 

better assess the extent and/or severity of program acquisition risks.
Page 26 GAO-05-6 Global Hawk Acquisition

Regarding our second recommendation to delay further procurement of the 

RQ-4B (other than units needed for testing) until a new knowledge-based 

and risk-reducing business case is prepared, DOD stated that its current 

acquisition strategy effectively manages risk and fosters the rapid delivery 

of needed capabilities to the warfighter. DOD said we overstated risks from 

RQ-4B development, design changes, and insertion of advanced sensor 

capabilities. DOD further stated that our recommendation would result in a 

production break with serious cost and schedule complications and that 

GAO’s sequential knowledge-based approach does not consider real-world 

events, such as the September 11, 2001, terrorist attack in the United States 

or issues related to North Korea and Iraq.

We believe the risks in the Global Hawk program are real and continue to 

support delaying the near-term procurement of air vehicles not needed for 

testing. We think this is a prudent way for the program to gain knowledge 

before significantly increased resource investments and to reduce risks 

until a new air vehicle integrated with the advanced signals intelligence 

payload and the multiplatform radar can be demonstrated through testing 

to meet warfighter requirements. Our report notes that operational testing 

of the air vehicle’s performance and suitability will not take place until 

almost half the fleet is already purchased and that integration and testing of 

the advanced sensors will not occur until late in the program after the fullrate production decision is made and most systems are bought. DOD’s 

comments appear to decouple the air vehicle from the advanced sensors by 

stating that, if a sensor diverges from its current plan, alternate future 

payloads could fill the RQ-4B’s greater payload capacity. However, the need 

for designing a new larger air vehicle was predicated on its ability to carry 

these specific sensors to meet the warfighter’s requirements. Therefore, we 

believe that knowledge based on a demonstration of the integrated 

capability is key to supporting production and delivery of the product 

within estimated cost and schedule. Additionally, the new Global Hawk 

program strategy requires significantly greater amounts of funding earlier, 

putting that investment at risk should changes occur as development and 

testing is completed.

Regarding a potential break in production, our analysis indicates that a 

break is neither impending nor certain if our recommendation were 

adopted. We are not recommending that DOD stop production or reduce 

the total quantity but rather a near-term delay in procuring the portion of 

annual buys for air vehicles not needed for testing. Funds currently on 

contract and approved appropriations for fiscal year 2005 would continue 

production on the Air Force’s planned schedule through mid-fiscal 
Page 27 GAO-05-6 Global Hawk Acquisition

year 2007 at least. Only then would a production break or slowdown 

happen, and only if the Air Force has not yet prepared a business case to 

justify its investments beyond that point based on demonstrated product 

knowledge of the new air vehicle. If the current acquisition strategy and 

financial plan are feasible and appropriate, the Air Force would be able to 

prepare and justify a comprehensive business plan for the RQ-4B well in 

advance of a potential break.

DOD indicated that our knowledge-based acquisition approach was 

untimely and not adaptive to fast-changing world events. When we 

developed the knowledge-based approach, our high priority was to focus 

on better ways to deliver capability to the warfighter more quickly through 

incremental, or evolutionary, development. Our approach is based on a 

careful study of historical DOD acquisition programs and the best efforts in 

the private sector. Our prior work shows that proceeding without requisite 

knowledge ultimately costs programs more money and takes longer to 

complete than those adopting a more rigorous and comprehensive strategy 

basing investment decisions on key product knowledge—technology, 

design, and production maturity levels. DOD agreed with our findings and 

changed its acquisition guidance to reflect a knowledge-based approach. 

We note in this report that the original Global Hawks were produced 

through a successful demonstration program that effectively and quickly 

provided the warfighter with transformational intelligence, surveillance, 

and reconnaissance capabilities. Defense Contract Management Agency 

reports, contract cost reports, corporate briefings, design drawing changes, 

new tooling and new production processes, and the evident need for Air 

Force and prime contractor task teams to be extensively deployed to 

subcontractor facilities, all indicate that the RQ-4B program entails higher 

degrees of risk, greater management challenges, and significant changes 

from production of the RQ-4A and earlier demonstrators.

We believe that our recommendation to delay further procurement of the 

RQ-4B until a new knowledge-based and risk-reducing business case is 

prepared prudently balances real-world internal investment risks with 

military demands from real-world external events. The Air Force could 

have continued to deliver the capability of the Global Hawk that was the 

direct outgrowth of the demonstration program while allowing the sensor 

and radar technology time to mature before investing in a new larger and 

more risky Global Hawk program. This would have allowed continued 

delivery of the enhanced RQ-4A capability to the warfighter while 

minimizing the impacts of design changes that come out of normal 

development and testing and that grow more costly as a product enters the 
Page 28 GAO-05-6 Global Hawk Acquisition

production environment. The heavy cost of design changes after 

production is underway could impact DOD’s ability to respond to other 

warfighter needs in the post-9/11 world.

As arranged with your office, unless you publicly announce its contents 

earlier, we plan no further distribution of this report until 30 days from its 

issue date. At that time, we will send copies to interested congressional 

committees, the Secretary of Defense, the Secretary of the Air Force, the 

Secretary of the Navy, and the Director, Office of Management and Budget. 

In addition, the report will be available on the GAO Web site at 

http://www.gao.gov.

If you or your staff has any questions concerning this report, please 

contact me at (202) 512-4163 or Michael J. Hazard at (937) 258-7917. 

Other staff making key contributions to this report were Lily J. Chin, 

Bruce D. Fairbairn, Steven M. Hunter, Matthew B. Lea, Charlie Shivers, 

and Adam Vodraska.

Michael J. Sullivan

Director (Acting)

Acquisition and Sourcing Management
Page 29 GAO-05-6 Global Hawk Acquisition

Appendix I

Scope and Methodology ApApenednxidexiIs

To determine the effects of Global Hawk’s restructuring on cost, schedule, 

and performance goals, we compared the original acquisition strategy, 

two major revisions, and the current acquisition strategy as implemented. 

We identified changes in cost, quantity, fleet composition, and sensor 

capability mixes as well as overall consequences of restructuring on total 

funding requirements, annual budget requests, and program cycles for 

developing, testing, and producing the Global Hawk. We reviewed 

management plans, cost reports, contract files, progress briefings, and risk 

data to identify program execution efforts and results to date. We identified 

cost changes, schedule delays, and performance issues.

To evaluate whether the current acquisition approach can help forestall 

risks, we applied GAO’s methodology for assessing risks in major weapon 

systems. This methodology is derived from the best practices and 

experiences of leading commercial firms and successful defense 

acquisition programs. We reviewed program office and prime contractor 

organizations, processes, and management actions. We extracted and 

evaluated program and technical risks maintained in a risk database used 

by the program office and contractor to identify major risks and the steps 

taken to mitigate risks. We compared the program office’s plans and results 

to date against best practice standards in achieving product knowledge in 

terms of technology, design, and production maturity information and in 

applying knowledge to support major program decisions. We identified 

gaps in product knowledge, reasons contributing to those gaps, and the 

elevated risks expected as a consequence of inadequate product 

knowledge. We further analyzed original and current acquisition 

approaches to demonstrate the high concurrency of development, 

production, and testing and the elevated risks imposed as a result.

In performing our work, we obtained information and interviewed officials 

from the Global Hawk System Program Office, Wright-Patterson Air Force 

Base, Ohio; 452nd Flight Test Squadron, Air Force Flight Test Center, and 

Detachment 5, Air Force Operational Test and Evaluation Center, Edwards 

Air Force Base, CA; Defense Contract Management Agency, San Diego and 

Palmdale, CA; Northrop Grumman Integrated Systems, Rancho Bernardo 

and Palmdale, CA; and offices of the Director, Operational Test and 

Evaluation, and Unmanned Aerial Vehicle Planning Office, which are part 

of the Office of the Secretary of Defense in Washington, D.C.

We conducted our work from February to September 2004 in accordance 

with generally accepted government auditing standards.
Page 30 GAO-05-6 Global Hawk Acquisition

Appendix II

Comments from the Department of Defense ApendxiI
Appendix II

Comments from the Department of Defense

Page 31 GAO-05-6 Global Hawk Acquisition

Note: Page numbers in the 

draft report may differ from 

those in this report.
Appendix II

Comments from the Department of Defense

Page 32 GAO-05-6 Global Hawk Acquisition
Appendix II

Comments from the Department of Defense

Page 33 GAO-05-6 Global Hawk Acquisition
Appendix II

Comments from the Department of Defense

Page 34 GAO-05-6 Global Hawk Acquisition
Page 35 GAO-05-6 Global Hawk Acquisition

Appendix III

Knowledge Gaps at Critical Knowledge Points ApendxiI

Technology Maturity Gap—

Knowledge Point 1

Achieving a high level of technology maturity at the start of system 

development is a particularly important best practice. This means that the 

critical technologies needed to meet essential product requirements are in 

the form, fit, and function needed for the intended product and have been 

demonstrated to work in their intended environment. The RQ-4B 

development program is struggling to meet these criteria for several of its 

most critical technologies. More than 2 years after development began, the 

technologies required for the RQ-4B to perform its operational mission 

including enhanced imaging sensors, signals intelligence, multiplatform 

radar, and open system architecture are immature, basically at a functional 

rather than form or fit configuration. Nevertheless, the Air Force continues 

to build the RQ-4B platform, lacking solid assurance that these critical 

subsystems will work as planned.

In particular, the airborne signals intelligence payload and multiplatform 

radar technology insertion program are still in development under separate 

Air Force programs and will be purchased by the Global Hawk program as 

government furnished equipment. These subsystems are key to providing 

the advanced intelligence, surveillance, and reconnaissance capabilities for 

which the RQ-4B is being developed. At the time of our review, neither of 

these technologies had been demonstrated in an operational environment 

using a system prototype. Air Force officials characterized their current 

stages of development as laboratory settings demonstrating basic 

performance, technical feasibility, and functionality but not form or fit 

(size, weight, materials, etc.). Technology maturity of the sensors is critical 

because the basic design of the RQ-4B has been completed and allocates 

limited space, weight, and power for the new capability. If the new sensors 

cannot be developed within these constraints, some performance 

trade-offs—such as reduced frequency coverage—are likely. The airborne 

signals intelligence payload currently exceeds the weight allocated for its 

integration into the RQ-4B, while the multiplatform radar uses most of the 

vehicle’s available power-generation capability.

Officials expect them to be mature by the time they begin buying sensors to 

incorporate them into the Global Hawk production line in fiscal years 2008 

and 2009. However, by this time most of the air vehicles will have already 

been bought; additional time and money might be needed to fix or retrofit 

any remaining differences. Also, operational testing to evaluate 

performance in a realistic operating environment is not scheduled until late 

fiscal year 2008 for the signals intelligence sensor and late 2010 for the 

radar. Any changes or delays in these programs would likely impact Global 

Hawk cost, schedule, and/or performance.
Appendix III

Knowledge Gaps at Critical Knowledge 

Points

Page 36 GAO-05-6 Global Hawk Acquisition

Design Maturity Gap—

Knowledge Point 2

Seventy-five percent of engineering drawings were released at the 

Global Hawk design readiness review that triggered the start of RQ-4B 

manufacturing and assembly. This figure is 15 percent less than the best 

practices’ standard of 90 percent. The Air Force and contractor had 

anticipated being able to use much of the design work and production 

experience on the RQ-4A to prove the design and decrease the time and 

extent of engineering work on the RQ-4B. However, officials found out that 

the two models had much less in common than anticipated. About 

90 percent of the airframe had to be redesigned—only 10 percent was 

common to both models. Therefore, relying on the experience of the RQ-4A 

increased the risk of poor program outcomes because the RQ-4B is 

substantially heavier; incorporates a new wing, fuselage, and vertical tail; 

has a 50 percent greater payload capacity to carry advanced sensors still in 

development; and requires new production tooling, new materials, and 

changed manufacturing processes.

The Air Force also did not build an RQ-4B prototype—a best practice to 

demonstrate design stability—before awarding a contract to start 

production. An analysis of the development contract performance, as of 

May 2004, shows that development and integration efforts needed to 

finalize the design and prepare the RQ-4B for production is behind 

schedule and over cost. The planned work efforts were just over one-half 

completed, but two-thirds of the budget allocated for these efforts was 

expended. Defense Contract Management Agency analysts cited cost 

growth in labor and materials and problems in finalizing and releasing 

design drawings as causes for the problems.

Neither the original nor the current plan established comprehensive 

reliability targets and growth curves. Reliability growth is the result of an 

iterative design, build, test, analyze, and fix process. Improvements in 

reliability of a product’s design can be measured by tracking reliability 

metrics and comparing the product’s actual reliability with the growth plan 

and, ultimately, to the overall goal. Although both models are in production, 

the Air Force did not establish reliability growth programs to measure how 

reliability is improving and to uncover design problems so fixes could be 

incorporated before the design was frozen and before committing to 

production.
Appendix III

Knowledge Gaps at Critical Knowledge 

Points

Page 37 GAO-05-6 Global Hawk Acquisition

Production Maturity Gap—

Knowledge Point 3

Officials have started to identify the critical manufacturing processes for 

the RQ-4B but do not intend to collect and use statistical process control 

data to ensure that the manufacturing could deliver quality products within 

best practices quality standards and that the end product meets the design 

and specifications. The officials’ assessments of the program continue to 

identify significant concerns about the quality, performance, and timeliness 

of the work of several subcontractors. For example, the subcontractor 

building the vertical tail and main parts of the fuselage is new to large-scale 

manufacture using advanced composite materials. The firm experienced 

significant start-up problems and the prime contractor and DOD sent 

special teams of advisors to help develop the firm’s manufacturing 

processes and to train employees. The subcontractor’s critical processes 

must be demonstrated to ensure good quality and limit rework. Officials 

have identified similar concerns with the subcontractors building the wing 

and imaging sensor.

The Air Force started producing the A and B models without first 

demonstrating that the systems would meet reliability goals. Reliability is a 

function of the specific elements of a product’s design and making changes 

after production begins is costly and inefficient. Best practices for system 

development require reliability to be demonstrated by the start of 

production. The RQ-4A is a production version of the demonstrators with 

few changes. Testing of the demonstrators identified a need to evaluate 

reliability under a stressful operating tempo. Air Force officials told us that 

reliability improvements on the RQ-4A were constrained, as were 

demonstrations of reliability. The RQ-4B design has incorporated 

improvements in such areas as flight control actuators, mission computers, 

avionics, and structures that officials expect will fix some of the identified 

problems and improve reliability, but these have not been demonstrated.

Finally, the Air Force did not acquire and test a fully integrated system 

representative prototype before committing to production. The contract 

for the first three units was awarded and work began in late fiscal year 

2004. Budget plans call for procuring 13 RQ-4Bs in low-rate production 

through the fiscal year 2006. The Air Force has also programmed advance 

procurement funds in fiscal year 2006 for 7 more, meaning that the 

government will have made investments in 20 RQ-4Bs—45 percent of the 

entire RQ-4B fleet—before the basic air vehicle is flight tested and before 

evaluations are made leading to the full-rate production decision, 

scheduled in fiscal year 2007. The Air Force also plans to enter full-rate 

production without complete testing to demonstrate that a fully integrated 

system—with advanced sensors and data links—will work as intended, is 
Appendix III

Knowledge Gaps at Critical Knowledge 

Points

Page 38 GAO-05-6 Global Hawk Acquisition

reliable, and can be produced within cost, schedule, and quality targets. 

Initial operational test and evaluation will only test the RQ-4B air vehicle 

with its basic imagery intelligence payloads. Complete operational testing 

and incorporation of the advanced signals intelligence payload and the 

multiplatform radar capabilities—the reasons for acquiring the larger 

model in the first place—will not occur until later in the program, after the 

full-rate decision is made.

In the absence of specific product knowledge required by best practices 

and DOD acquisition guidance, the Air Force and its contractor are 

depending on the operational experience of the demonstrators, lab 

modeling and simulation efforts, and production of the RQ-4A to help 

“close the gaps” and provide some assurance on the RQ-4B design maturity, 

its reliability, and its producibility within cost, schedule, and quality targets. 

Although the demonstrator program had notable successes, testing 

identified significant improvements were needed before producing 

operationally effective and suitable air vehicles. Areas needing 

improvement included reliability under a stressful operating tempo, 

performance of sensors, mission planning, and communications bandwidth 

burden. We also note that the RQ-4A is a production version of the 

demonstrators with few changes and that government acceptance of the 

second production RQ-4A was delayed due to deficiencies, including flight 

problems. Moreover, as previously discussed, the RQ-4B is significantly 

different than the RQ-4A and requires investing in new tooling and changed 

manufacturing processes. These factors contribute to increased risks of 

poor cost, schedule, and performance outcomes due to incomplete product 

knowledge.
Page 39 GAO-05-6 Global Hawk Acquisition

Related GAO Products

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GAO-04-248. Washington, D.C. Washington, D.C.: March 31, 2004.

Force Structure: Improved Strategic Planning Can Enhance DOD’s 

Unmanned Aerial Vehicles Efforts. GAO-04-342. Washington, D.C.: 

March 17, 2004.

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Practices, but More Controls Are Needed. GAO-04-53. Washington, D.C.: 

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Defense Acquisitions: Matching Resources with Requirements Is Key 

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Weapon Systems’ Total Ownership Costs. GAO-03-57. Washington, D.C.: 

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Early Improves Acquisition Outcomes. GAO-02-701. Washington, D.C.: 

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Unmanned Aerial Vehicles: Progress of the Global Hawk Advanced 

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Page 40 GAO-05-6 Global Hawk Acquisition

Unmanned Aerial Vehicles: DOD’s Demonstration Approach Has 

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System Program Implement Best Practices. GAO/NSIAD-99-206. 

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Can Improve Weapon System Outcomes. GAO/NSIAD-99-162. 

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Defense Acquisition: Improved Program Outcomes Are Possible.

GAO/T-NSIAD-98-123. Washington, D.C.: March 18, 1998.

Best Practices: DOD Can Help Suppliers Contribute More to Weapon 

System Programs. GAO/NSIAD-98-87. Washington, D.C. March 17, 1998.

Best Practices: Successful Application to Weapon Acquisition Requires 

Changes in DOD’s Environment. GAO/NSIAD-98-56. Washington, D.C.: 

February 24, 1998.

Major Acquisitions: Significant Changes Underway in DOD’s Earned 

Value Management Process. GAO/NSIAD-97-108. Washington, D.C.: 

May 5, 1997.

Best Practices: Commercial Quality Assurance Practices Offer 

Improvements for DOD. GAO/NSIAD-96-162. Washington, D.C.: 

August 26,1996.

(120296)
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