Defense

Promise and Challenges

Unmanned combat aerial vehicles (UCAVs) have the earmarks

of becoming one of the disruptive technologies that transform conventional military operations across the full spectrum of combat scenarios from peacekeeping to regional wars. In battle, forces engage

an adversary by either direct combat or indirect fires. Indirect fires,

or standoff engagements, preserve forces and are preferred whenever available and effective. UCAVs promise to carry the concept of

indirect fires to a new level. They will be more flexible than missiles

in time-sensitive target selection and more readily expendable in

high-risk environments than manned systems, and they will have a

greater sustained battle presence than either missiles or manned

systems. In time, UCAVs may liberate manned systems (such as airborne warning and control systems [AWACS] or joint surveillance

and target attack radar systems [JSTARS]) from such routine missions as command, control, and communications protection or carrier battle group air cover. They may also perform a majority of the

sorties for long endurance operations, such as Northern Watch and

Southern Watch over Iraq. Eventually UCAVs may be so sophisticated

that they will be safer than manned systems for close support of

ground forces and more successful than manned aircraft in air-to-air

combat. They could someday join the air defense arsenal against 

either strategic ballistic missiles or cruise missiles.

The intersection of technology advances, national security policy, and operational requirements has led to the commitment to

Overview

The Bush administration and Congress are in concert on the goal

of developing a fleet of unmanned aircraft that can reduce both

defense costs and aircrew losses in combat by taking on at least

the most dangerous combat missions. Unmanned combat aerial

vehicles (UCAVs) will be neither inexpensive enough to be readily expendable nor—at least in early development—capable of

performing every combat mission alongside or in lieu of manned

sorties. Yet the tremendous potential of such systems is widely

recognized, and allies as well as potential adversaries are moving

quickly to mount their own research and development programs.

The United States is committed to fielding UCAV capabilities by

2010, principally for the missions of suppression of enemy air

defense and deep strike, which are among the highest risk tasks

for the Air Force and naval aviation.

Currently, UCAVs are unproven, infant technologies just

being designed, simulated, and demonstrated. Enthusiasts must

be aware that significant technological, policy, and operational

challenges must be met. An operational UCAV capability is not

expected to be available to U.S. field and fleet commanders for

10 years. Yet a nexus of mature technologies, policy support, and

operational needs has been reached, and it is both possible and

necessary to accelerate development of UCAVs. Their potential is

apparent, and there is sustained momentum behind programs for

all the services.

October 2001 Defense Horizons 1

UCAVs—Technological, Policy, 

and Operational Challenges

by Charles L. Barry and Elihu Zimet

Center for Technology and National Security Policy

The National Defense University established the Center for Technology and National Security Policy in June 2001 to study the implications of technological innovation

for U.S. national security policy and military planning. The center combines scientific and technical assessments with analyses of current strategic and defense

policy issues. Its major initial areas of focus include: (1) technologies and concepts that encourage and/or enable the transformation of the Armed Forces, 

(2) developments by defense laboratories, (3) investments in research, development, and acquisition and improvements to their processes, (4) relationships among

the Department of Defense, the industrial sector, and academe, and (5) social science techniques that enhance the detection and prevention of conflict. The staff is

led by two senior analysts who will hold the Roosevelt Chair of National Security Policy and the Edison Chair of Science and Technology and who can call on the

expertise of the university community and colleagues at institutions nationwide. The papers published in the Defense Horizons series present key research and

analysis conducted by the center and its associate members.

A publication of the

Center for Technology and National Security Policy

National Defense University

OCTOBER 2001

Number 3

Horizons
near-term UCAV deployment. However, an array of technological,

policy, and operational challenges must first be overcome:

Technology

■ On-board signal processing, decision aids, and wideband data network links must afford a satisfactory mix of autonomous operation and manin-the-loop (MITL) decisionmaking.

■ Advanced electro-optical, infrared, and radio frequency (EO/IR/RF)

passive and active sensors must provide for accurate target detection, designation, and engagement for both moving and stationary targets.

■ Airframes and systems must be survivable against more capable airand ground-based countermeasures, including missiles, gunfire, or energybased weapons. Stealth technologies will be crucial.

■ Automatic flight controllability will have to extend to a broader

range of fight profiles, including hypersonic speed and evasive maneuvers in

excess of human tolerances (9 times the force of gravity).

■ New airspace/air traffic aids must network UCAVs into the broader

airspace system without degrading other airspace users in terms of flexibility, responsiveness, and proximate engagement. These technologies must

include automated landing and ground/deck operating systems.

■ Propulsion systems must be developed that match desired efficiencies in terms of aircraft size, fuel duration, reliability, and survivability.

Policy

■ Conventional arms controllers eventually will have to decide

whether to classify UCAVs as systems to be counted under existing definitions of combat aircraft or to amend the Conventional Forces in Europe

(CFE) Treaty to count a new category of weapon systems.

■ The degree of autonomy to be built into unmanned vehicles will be

a policy issue as well as a technical question. At least for the near term, an

MITL decisionmaker will have to be included.

■ Service cultural issues related to investing in unmanned capabilities at the expense of manned systems raise a host of secondary policy issues

as budgetary realities require program decisions to be made.

■ If coalition partners are to bring modern forces to operations, technology must be transferred to allies willing to purchase or be licensed to

build UCAV systems using American technologies.

Operational Concepts

■ Unmanned combat aircraft will have to be at least as effective as

manned aircraft in terms of availability, ease of integration into the overall

battle plan, and mission success rates, as well as being cost effective.

■ As operational airspace users, UCAVs must be responsive to a continuously changing airspace management picture and must not restrict

other users critical to successful prosecution of the battle.

■ UCAVs must feature handoff capability to a central air battle operations center capable of controlling the full array of unmanned systems with

a single architecture.

■ Roles and missions for UCAVs must be determined and prioritized.

Particular high-risk missions that UCAVs might take on are suppression of

enemy air defense (SEAD) and deep strike against some stationary targets,

especially targets that may be rapidly relocatable.

Nexus of Technology and Political Support

The U.S. military has experimented with unmanned aircraft for

half a century and has resolved a host of technological obstacles to

military employment. The right mix of operational requirements and

available technology presented itself in 1999 over Kosovo, where U.S.

and NATO forces used unmanned aerial vehicles (UAVs) extensively

to collect intelligence on Serb forces and targets. The Kosovo operation was a benchmark, demonstrating that UAVs had an important

place on future battlefields in the missions of intelligence, surveillance, and reconnaissance (ISR).

Since Operation Allied Force, many countries have taken the

next logical step in the application of unmanned or robotic aircraft:

the missions of target acquisition and engagement. Many countries

have initiated UCAV programs, including France, Israel, Italy, and

the United Kingdom. Nowhere has UCAV development achieved

greater momentum than in the United States. President George

Bush and Secretary of Defense Donald Rumsfeld have made it a

highlight of their visions of defense transformation. In 2000, Congress added a provision to the 2001 Defense Authorization Act specifying that, within a decade, one-third of all U.S. deep-strike aircraft

should be UCAVs. In 2001, Congress provided additional funding to

the Department of Defense budget to show that it wants to move forward without delay.

Defense planners see an operational need for a system that can

assume some of the current demands on manned systems, especially

high-risk and long-term patrolling missions. Americans are averse to

needless casualties if a better solution exists, notwithstanding a

resolve to defend their homeland at any price if threatened. U.S.

forces often face missions where few or no casualties are a proviso for

sustaining public support at home and abroad. Other missions consist

of continuous defensive patrolling or the monitoring of regions

against violations of international agreements, as in the case of Iraq.

Leverage from UAV Operations

The interest in UCAVs flows from the operational success of

UAVs. The U.S. fleet of UAVs has amassed more than 50,000 flight

hours and considerable operational experience. UAV technology continues to improve in terms of platforms, flight control systems, autonomy, and sensors. UAVs are proceeding to the next stages of research

and development and will integrate with UCAVs on the future battlefield to accomplish such missions as target identification and handoff. UCAVs may operate as armed UAVs for some missions or as UAV

protection. Some UAV and UCAV subsystems probably will use synchronous technologies and even interchangeable components.

Unmanned aerial technology gained momentum from the quest

for battlespace information dominance. Commanders in all battle

mediums—land, sea, and air—have ever-increasing demands for

streaming, real-time, full situational awareness of the battlespace.

Continuous information flows provide details of enemy forces, 

terrain/sea conditions, and weather, as well as friendly force locations. More sophisticated, all-weather UAVs give commanders a

unique perspective and enable them to dominate adversary decision

2 Defense Horizons October 2001

Lieutenant Colonel Charles L. Barry, USA (Ret.), is a Washington-based 

defense consultant; he may be contacted at (410) 827–5048 or via e-mail at

cbarryusa@aol.com. Elihu Zimet is the head of naval expeditionary warfare

science and technology in the Office of Naval Research; he may be contacted

at (703) 696–4773 or via e-mail at zimete@onr.navy.mil
cycles. UAV platforms, and the proposed man-portable organic air

vehicles (OAVs), will be able to operate from as far away as inner

space or as near as city rooftops. Unmanned platforms under development operate either at high altitudes (for example, Global Hawk at

60,000–70,000 feet) or in close proximity to the ground (for example,

hovering UAVs and OAVs). That flexibility reduces UAV operations in

the congested battlespace of manned combat aircraft. Still, UCAVs

must be able to operate—even continuously—alongside manned systems, which will create different demands on the autonomous operating capabilities and positive control of UAVs and UCAVs.

Unmanned systems such as Global Hawk are poised to enter

production and fielding with an initial operational capability in 2003,

years ahead of the first projected UCAVs. UAV experience will inform

the development of UCAVs, perhaps most notably in the area of networked systems and airspace management. From a systems design

perspective, UCAV development may borrow more technologies from

manned platforms.

Cost

Most experts agree that building UCAVs in projected quantities

will cost less per unit to acquire, operate, and maintain than manned

aircraft. However, they will still require significant research and

development (R&D) investment to bring them to the point of production. UCAVs are expected to cost in the millions of dollars, though

an approximate unit cost is hard to define without knowing the platform numbers and identifying the suite of onboard systems, data

links, and ground control stations. The unarmed Global Hawk UAV

just coming into production is estimated to cost approximately $50

million, roughly the same as the vintage U–2 that it is designed to

replace. However, once R&D costs

are amortized across a larger fleet,

the UCAV unit cost is anticipated to

drop to around $30 million or less—

about half that of a manned system.

More important than acquisition cost savings will be lower

UCAV operating costs. Unlike pilots, UCAV controllers (who probably

will be recruited from military pilots or navigators) will train almost

solely in simulators, and their UCAVs will be maintained in ready

storage, perhaps for years. Hence the operating and support (O&S)

costs should afford even greater life cycle cost savings than initial

procurement. UAVs, because of their peacetime ISR missions, will

not achieve the same level of O&S savings as UCAVs. Before O&S savings are calculated with any certainty, however, further study will be

required on the ground support investment that UCAVs generate.

UCAVs should suffer far lower accident rates than either manned aircraft or UAVs because they will be stored and used only for limited

training during peacetime, when manned combat aircraft fly the

majority of their sorties (95 percent) and incur their highest losses

(261 of the 265 F–16 losses as of 2000 occurred during training).

The other side of the cost equation is deciding whether to

engage targets with long-range (ballistic or cruise) missiles or with

UCAVs, which would be the more expensive choice but would offer a

multiple-mission platform. On the other hand, missiles, such as the

conventional Tomahawk, are less costly (albeit still expensive) but

are one-time-use munitions. Both cruise missiles and UCAVs offer the

same unmanned standoff engagement with regard to concerns about

combat casualties; therefore, the decision variables will be cost and

assurance of target destruction. If the target is mobile or fleeting,

UCAVs may offer greater assurance of target engagement, and cost

concerns would be secondary. Conversely, using Tomahawks against

known but well-defended fixed targets, such as the attack against

Iraqi weapons of mass destruction (WMD) sites in early 2001, avoids

unnecessary loss of UCAVs while offering a high degree of assurance

of target destruction.

Converting obsolete aircraft to UCAVs—the so-called scrapyard

option—has surfaced as both more cost effective and available much

sooner than the option to research and develop new aircraft. Commercial companies such as Lockheed Martin and Texas-based Mission Technologies have proposed using F–16s and A–10s as UCAVs.

Members of Congress and the Air Force also have voiced support for

this approach to UCAV fielding.

Nonetheless, as the battlefield becomes more sophisticated and

counter-UCAV systems proliferate, antiquated systems will become

more vulnerable and ultimately will have to be replaced by high-tech

UCAVs if they are to take on essential operational roles. 

UCAV Systems

A UCAV is actually a system of systems requiring full operational

support services. A single aerial vehicle consists of an advanced airframe and its onboard suite of flight controls, weapons, guidance packages (including multiple target sensors, designators, and handoff data

links), survivability features, perhaps

an aerial refueling system, and a

propulsion system. Each UCAV system is composed of a number of aerial vehicles and a ground control station (GCS).

Like manned aircraft, UCAVs

will be formed into squadrons of several systems and accompanied

by ground support equipment, spare parts/supply, and maintenance

personnel. Unmanned craft will have to be supported by planners for

deployments and routine services, such as fuel/ordnance resupply

and weather information. Operating bases with UCAVs will require

facilities and special mapping plans for UCAV ground operations.

As UCAVs grow in sophistication, so will their cost and operational value. Neither UCAVs, UAVs, nor any other unmanned system

will be low-cost and readily expendable. Using unmanned systems

for only a single sortie, or even for a limited number of sorties,

would be short-sighted. Commanders can be expected to husband

UCAVs on the battlefield as they would any other limited, hard-toreplace resource.

Because UCAVs will not fly extensively in peacetime, they

should actually have more combat potential than manned systems in

terms of sortie generation rates. Unmanned systems should be

October 2001 Defense Horizons 3

once R&D costs are amortized,

UCAV unit cost is anticipated

to drop to about half that of a

manned system
4 Defense Horizons October 2001

designed to the same standards of reliability, survivability, and autonomy as manned systems. The magnitude of this challenge is reflected

in a 2000 Department of Defense study that noted UAVs have experienced mishaps at 10 to 100 times the rate of manned aircraft.

U.S. Programs

The Predator-Hellfire UCAV demonstration. In early 2001, the

Air Force conducted the only successful UCAV demonstration to date

when it engaged a stationary tank by firing Hellfire laser-guided missiles from a modified Predator UAV platform that both lased and

engaged the target. The Predator is the best known UAV, with combat experience in Kosovo. The Predator is not being developed as a

future UCAV, but serves as a UCAV concept demonstrator, and could

fulfill an interim operational UCAV role.

The Defense Advanced Research Projects Agency (DARPA)/Boeing/Air Force X–45 program. The X–45 system is being designed as

a pure UCAV vehicle optimized for the missions of hunter-killer

SEAD and precision air-to-ground strike. It will be autonomous,

rather than remote-controlled, able

to operate if controller communications are jammed. Two X–45As are

undergoing engine and flight-testing this year. An X–45B is under

design and will be a higher fidelity

version for evaluation of the ultimate UCAV platform and systems,

including off-the-shelf weapon systems. Production versions will be low-observable, almost all-composite aircraft and will incorporate electronic surveillance measures

and satellite link data/communications equipment. The program

plans to move from technical testing to mission testing in 2003 and

start engineering and manufacturing development (EMD) in 2008.

The DARPA/Navy UCAV–N program. The UCAV–N program is

only in the preliminary design phase but is expected to reach EMD

by 2008, with Boeing and Northrop Grumman competing in the program. The UCAV–N will be a dual-role reconnaissance UAV and

attack UCAV aircraft. It is expected to be larger than the X–45 and

have greater range and payload. The Navy is asking for a UCAV with

a 4,000-pound payload, a 650-nautical-mile radius, and a 12-hour

surveillance duration. The UCAV–N must be capable of carrier operations integrated with manned systems, which may require remotecontrolled arresting gear and steering. A key capability for UCAV–N

will be shipboard takeoff and landing guidance systems. An experimental technology, the shipboard relative global positioning system

(SRGPS), converts the absolute positioning of a global positioning

system (GPS) into positioning relative to a ship’s deck, taking into

account the ship’s forward motion, heave, and sway. Accuracies for

the SRGPS are expected to be 40 centimeters. The reconnaissance

mission of the UCAV–N will put it in the maintenance profile of other

UAVs—that is, it will not be stored in peacetime (like UCAVs) but

will operate routinely and require more robust maintenance and

support. Northrop Grumman has invested in Pegasus, a scale-model,

kite-shaped UCAV–N that is due to fly in late 2001.

The DARPA/Army/Boeing UCAV program. The Army is considering a rotary-wing UCAV concept proposed by Boeing. The Canard

Rotor-Wing concept lands and takes off like a helicopter, but the

rotor stops and converts to a jet-powered wing in flight. The concept

to date is simulation-based; however, a test flight model has been

developed and is expected to fly later this year. The project is a part

of the Army’s overall Future Combat Systems initiative and may be

either a UAV or UCAV.

Foreign Programs

The technology for unmanned aerial vehicles is widespread,

with 55 countries operating almost 80 types of UAVs. The following

are indications of international developments moving toward UCAV

technology.

France. Dassault Aviation flew a small stealth UCAV demonstrator called Petit Duc in July 2000. Dassault is now working on a

larger demonstrator with greater autonomy and range called Moyen

Duc that could be flying in 2002. These early demonstrators are

intended to lead to a full-size stealth UCAV somewhat smaller than a

manned fighter and capable of carrying standard fighter weapons.

The French concept is to control the

UCAV from an airborne station in

the backseat of a manned fighter

several hundred miles away.

Germany and the United Kingdom. Both are studying the use of a

UCAV capability to pick up some of

their manned air-to-ground fighter

missions.

Israel. Israel has logged more UAV hours than the United States

and is reported to be pursuing an active UCAV program.

Italy. Italy has indicated interest in buying the Predator as a

UAV, which may afford the Italian military with a ready-made UCAV

capability should recent U.S. tests result in an operational variant of

the Predator. Italy is also considering the conversion of obsolete

F–104s to unmanned use.

Russia. Indications are that Russia may not be actively engaged

in a UCAV program. However, it operates several UAVs, including the

800-kilometer-per-hour Reis and the slower, tactical Pchela series of

UAVs. The maker of the Pchela, Kulon Scientific Research Institute,

and the Yakovlev Design Bureau, a major Russian military aircraft

manufacturer, have been urged to take the next logical step and

develop a larger UAV that can carry bombs and missiles.

Technology Status and Challenges

The introduction of a new operational military system generally

follows the intersection of a recognized operational need and the

maturation of enabling technologies. The successful utilization of

UAVs in combat has provided the U.S. military with a nascent concept for other unmanned systems. The post-Kosovo development of

UAVs has enhanced the technology base in autonomous control,

MITL guidance, and ground station displays and control.

Perhaps counter-intuitively, the principal technology enablers

for UCAVs come from technology developments in manned aircraft,

the technology for unmanned

aerial vehicles is widespread,

with 55 countries operating

almost 80 types of UAVs
advanced sensors, high-speed processing, and networking rather

than from UAV developments. Hence, UCAV performance requirements are more aligned with those of the manned aircraft. Current

requirements for manned aircraft have led to the need to apply computer-aided dynamic flight control for stable flight (the plane is not

stable if the flight controls are locked down). In addition, the shaping of the airframe to reduce radar signature has led to aerodynamic

compromises and thus to more computer control. In parallel with

aircraft development has been the development of advanced sensors,

including imaging radars, hyperspectral infrared sensors, and passive and active millimeter wave radar. These and other sensors, coupled with high-speed signal processing hardware and algorithms,

provide far more information

than the unaided human eye.

With the computer operating

the aircraft and the primary

information coming from sensors, taking the pilot out of the

aircraft and providing remote

oversight is not inconceivable.

Basic technologies are in

place to build a prototype UCAV

with a limited mission set. Yet

significant technology challenges await if UCAV is to develop a multimission capability in a complex battlespace environment. These

challenges include the following:

Intelligent autonomy. The level of autonomy allowed a UCAV is

both a great technical challenge and the most contentious issue in

terms of capability, weapon release authority, and deconfliction with

other platforms. The tremendous increase in processing speeds and

software development has enabled significant advances in

autonomous control and decision aids. Major advances in autonomy

are still required, even with offboard oversight, before UCAVs will be

operational with weapon release authority in unrestricted airspace.

Required technology development includes the development of

fault-tolerant, behavior-based intelligence and adaptive reasoning

systems (such as neural networks). Fusion of information from multiple diverse sensors and the processing of data will be required to

form a real-time situational assessment. Automated detection and

combat identification need to be significantly enhanced. The technology for real-time, on-the-fly mission-management and route planning needs development. Other technologies include autonomous

sensor management and operator decision aids and displays. The

systems developed must be fault tolerant, highly reliable and maintainable, and should incorporate modular low-cost electronic and

micro-electrical-mechanical systems.

Network connectivity. Equal in importance is the need to network UCAVs with manned aircraft, other UAVs, offboard sensors,

and ground stations for overall battle management. The cooperative

engagement capability and development of the single integrated air

picture have demonstrated the value of cooperative, inter-platform

operations. Further technology development is required for responsive command, control, and communications (C3

) battle management. These technologies include wideband, secure, and allweather data links. Also required are distributed, high-speed

processing and video/data compression techniques to reduce the

demand for bandwidth. Digital “software” radios are another new

technology. High-data-rate transmission radios are needed to handle the proliferation of dedicated data links for new weapon and

communication systems, including UCAVs, which may lead to

dynamic wireless networking.

Airspace management. Unmanned aircraft will bring a new

dimension to airspace management. The solution to management

problems must include rule-based operational procedures and protocols for deconfliction of assets coupled with the technology to realize the concept. In addition to the need for robust, wideband data

links and a single, integrated air picture, airspace management

requires significant advances in precision navigation and in

space/time positioning (GPS

and inertial measurement unit

[IMU] development have significantly increased this capability). A specific concern is the

return of UCAVs to base with

live munitions. If the base is an

aircraft carrier, the problem is

even more complex. Technology

challenges include the development of an anti-jam GPS system, very-low-drift-rate IMUs, collision detection and avoidance systems, air-traffic control and mission management algorithm

development, precision landing aids such as the SRGPS for carrierbased UCAVs/UAVs, and the influence of the weather on the operational environment.

Platform and platform components. Few of the components of

the actual UCAV platform (outside of the flight management system)

are unique to the vehicle. However, the expectation for expanding

the mission set from SEAD and deep air interdiction to battlefield air

interdiction, air superiority (including missile defense), and close

air support will require more endurance, greater maneuverability,

increased weapon payloads, and faster target acquisition. During the

past 10 years, turbine engine development has increased the thrustto-weight ratio by about 80 percent for manned aircraft, with more

increase feasible. Engine development for a UCAV would be sized to

a smaller vehicle, with cost and signature as significant drivers.

Because a UCAV is not constrained in maneuverability by human tolerance for acceleration, its propulsion and airframe could be

designed for higher maneuver capability. A more immediate goal for

the UCAV is to develop propulsion and airframe for endurance and

stealth. The elimination of the cockpit gives the UCAV significant signature advantages. Stealth design and materials have matured considerably since the F–117. A UCAV will depend on robust data links

and operate in a netted environment, so its onboard sensor suite may

not need to be comprehensive. Specialized sensors may be required

for unique attributes of the UCAV involved in collision avoidance,

landing, and perhaps mid-air refueling.

Weapons and targeting. The utility of a UCAV would not be

enhanced if it required unique weapons. Fortunately, the direction of

developments in current air-launched weapons from low-signature

October 2001 Defense Horizons 5

expanding the mission set will

require more endurance, 

greater maneuverability, increased

weapon payloads, and faster

target acquisition
Support Initiative of 2000. Industry will seek overseas sales within

the law, and allied access to UCAVs will improve their capability to

close the UCAV technology gap. The main concern is to guard against

risks to national security through technology transfers that end up in

the hands of adversaries.

NATO UCAV capability, standards, and interoperability. The

Alliance might be moved to invest in UCAVs as a NATO rather than

member-owned resource. However, NATO is more prone to negotiate

a common standard and encourage its members to design their

national systems to Alliance specifications to achieve interoperability. Unless NATO can set and adhere to standards for essential functions, such as secure data transfer and discreet target designation,

national systems would not be interoperable in a military operation.

Levels of UCAV autonomy. Autonomy is a policy issue and an

operational factor as well as a technological challenge. On the policy

level, there are concerns about “robotic warfare”: warfare conducted

by machines that seek, locate, identify, and attack targets without a

person in the loop for decisionmaking. Therefore, a key policy issue to

consider as UCAVs are designed

and tested is balance between

autonomy and MITL control. Scenarios could arise in which one

target must be distinguished from

another. Policymakers have

become more sensitive to these

issues than in the past. During the

Vietnam War, engagement with

unobserved fires (such as artillery or bombs) was routine when unattended ground sensors activated deep in enemy territory. UCAVs

should reach a higher level of target assurance than these older systems and methods. The incorporation of decision aids for information

synthesis and decision support will be essential to rapid identification of targets and options. Policymakers have a strong bias to build a

minimum MITL component into all UCAV systems.

Acquisition strategy. The debate over UCAV cost remains unsettled, yet the context for near-term investment under the Quadrennial

Defense Review 2001 is becoming more definitive. The present issue

is development and procurement, and these are the arenas in which

UCAV investments must compete head-on with such systems as the

V–22, Joint Strike Fighter, F–22, and Comanche. The defense budget

has increased for 2001 and is forecast to increase further in the next

two budget years. However, the highest priorities are for personnelrelated investment, homeland security, and missile defense, with

fewer increases for development and procurement. This means that

the services will face tough choices in supporting UCAVs in spite of

their potential to revolutionize warfare. Strategies devised to pursue

UCAV development and acquisition in this environment may include

limited-mission technology demonstrators and the use of

manned/unmanned aircraft to test subsystems and concept integration methodologies. However, initiatives for promising future technologies should not be cancelled.

Civil airspace safety and control. A more pressing challenge is

to integrate unmanned aircraft into U.S. and international civil airspace in a way that does not degrade the safety of civil aviation. So

aircraft is supportive of the UCAV concept. A significant attribute of

a UCAV-launched weapon would be a fire-and-forget capability.

Internal carriage and aircraft survivability have driven the next generation of missile seekers in this direction and away from the current

paradigm of laser or optically guided weapons requiring human

intervention. These new weapons will require low-cost imaging

infrared or millimeter-wave seekers that have become available. A

UCAV will be required to provide targeting coordinates and target

identification information to a weapon prior to release. The degree

of autonomy built into the targeting and weapon release will impact

the MITL degree of involvement.

Policy Issues

Training, exercising, and operating with coalition partners

(inside or outside NATO) will require new agreements to cover UCAV

integration. UCAV operations may be forced to rely on procedural

separation when links with allies are less reliable, leading to information voids or slow information

processing updates. Allies should

be encouraged to embrace the

technologies required for closely

integrated coalition operations,

including UCAVs from multiple

nations. In each case, the challenge will be to make an

informed decision about how

closely U.S. forces can operate with each ally and how to integrate

their capabilities.

Arms control. In late 2000, an American interagency legal team

concluded that UCAVs, which do not use launchers and are designed

to return to base, do not meet the definition of a cruise missile under

the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, and thus

are not subject to its provisions. Russia, the other party to the INF

treaty, has not responded to this position. The United States sees

UCAVs as a type of conventional aircraft and therefore potentially

subject to the 1990 Conventional Forces in Europe Treaty. As UCAVs

become more common, some parties may desire to control their

numbers under CFE. Some UCAV designs include tilt-rotor or helicopter technologies; however, most are of a fighter aircraft design.

Both attack helicopters and fighter aircraft are CFE-controlled

weapon systems. UCAVs could be subjected to the treaty, either

inclusively as part of a nation’s fighter aircraft holdings or as a new

category of systems. Treaty limits on fighter aircraft holdings are well

above current inventories of almost all signatories. Therefore, if

UCAVs were declared fighters under the treaty definition, there

would be little concern that they would displace manned systems.

More likely, as UCAV employment becomes more proximate, there

will be sentiment to amend the treaty to track them under a new definition. Except in Europe, no conventional forces treaties would

limit UCAVs.

Technology transfer. Some technology transfer will be necessary if allied UCAV programs are to keep pace with U.S. programs.

Technologies subject to export controls and limitations on foreign

military sales, including some components and complete systems

packages, are annually reviewed under the Defense Technologies

6 Defense Horizons October 2001

some technology transfer will be

necessary if allied UCAV

programs are to keep pace with

U.S. programs
The Navy may push faster than other services to employ UCAVs in

routine patrolling missions with long loiter times, such as antisubmarine warfare, electronic warfare, or carrier air cover. That use

could free up manned systems and increase the offensive capabilities of aircraft carriers.

Army UCAV missions. The augmentation of Army aviation

(attack helicopters) with Army-owned and -operated UCAVs will be

less immediate because Army missions will require more advanced

capabilities than envisioned for first-generation UCAVs. The Army

employs armed aircraft (helicopters and other service high performance aircraft) for close air support of ground troops or for relatively

close-in armed reconnaissance intended to develop the immediate

situation. Using unmanned aircraft for either mission would require

close coordination under rapidly changing combat situations.

Although such capabilities eventually will come, they are not entrylevel UCAV missions. One near-term mission worthy of study is UCAV

employment in nonpermissive tactical scenarios where ground

troops are not present, such as the 1999 situation in Kosovo that prevented the commitment of AH–64 Apache helicopters.

Airspace coordination. A combination of procedures and technologies will have to be assembled to allow UCAVs to operate in the

same airspace as manned systems and other systems, such as cruise

missiles, artillery and naval gunfire, bombs, laser designators, helicopters, and even weather balloons. Other coordination challenges

include ingress and egress across friendly lines where air defenders

track and engage unidentified targets, overflight of firing batteries,

mortars, helicopter refuel/rearm points, and a host of other danger

points that are constantly relocating on the battlefield. Continuous

availability of accurate information is key, as is the use of coded onboard interrogation equipment such as identification, friend or foe

(IFF) systems.

UCAV command and control (C2). All resources should be coordinated at the air operations center, even if different members of a

joint or multinational task force deploy several different UCAV and

UAV systems. UCAVs should be integrated into the air tasking order

like any other strike or support air asset. However, that integration

will be complicated if each system is designed to respond to its own

discrete controller, unable to accept hand-off to a single integrator at

the air operations center. Discrete controllers might mean deploying

October 2001 Defense Horizons 7

far, UCAVs and UAVs have operated solely in airspace restricted from

civil use with significant advanced written notification that can be

widely disseminated. The FAA and its international counterpart, the

International Civil Aviation Organization (ICAO), have safety as

their primary concern. All military aircraft, including unmanned,

must adhere to the fundamental rule of “see and avoid” when the aircraft is clear of clouds. Deployment of UCAVs to exercises or actual

operations would require coordination with the FAA and ICAO, and

it poses significant technology challenges.

Operational Issues and Challenges

UAV missions. UAV missions have developed through operational experience to include:

■ Crisis monitoring in nonpermissive environments

■ Pre-air-superiority situations

■ Peace operations surveillance, intelligence, operational, and strategic reconnaissance

■ Target acquisition and designation

■ Real-time operational and tactical battlefield decision support nodes.

UCAV Air Force/Navy missions. SEAD missions in support of

manned aircraft strikes against operational or strategic targets are

the most apparent UCAV mission for first-generation platforms.

These missions are high risk but essential for penetration air

attacks. UCAVs could also be used for deep strikes themselves,

including reconnaissance-strike missions and strikes against fixed

or mobile (versus moving) targets, such as enemy C3

I or logistics

nodes. UCAVs might be employed for strategic strike missions, such

as the 1986 raid on Tripoli, Libya. They could be used with cruise

missiles for greater assurance of target destruction in preemptive

strikes or for counterstrikes.

Unique Navy UCAV missions. The Navy has special UCAV design

and mission requirements because of the need to operate from aircraft carriers. UCAV–Ns will have to be multimission assets, capable

of both UCAV and UAV missions to conserve limited deck and hold

space aboard ships. They will need the rugged launch and recovery,

electromagnetic pulse shielding, and greater corrosion protection

characteristics of other carrier aircraft designed into all systems.

Priority Technologies

■ Intelligent autonomy to accomplish complex missions with minimal continuous human intervention. Technologies include behavior-based

intelligence, pattern recognition algorithms for combat identification, real-time mission and route planning, decision aids, and operator displays.

■ Network connectivity for dynamically managed, interoperable, high-capacity connectivity between UCAVs, manned aircraft, UAVs, offboard sensors, and ground stations. Technologies include broadband all-weather secure data links, distributed high-speed processing, and data

compression algorithms.

■ Airspace management for operation in a civilian airspace environment. Technologies include precision navigation and space/time positioning, anti-jam GPS, collision avoidance sensors and controls, and precision all-weather landing aids.

■ Platform and platform components to enhance maneuverability, endurance, payload, and survivability beyond the capability of manned

aircraft. Technologies include power and propulsion, signature reduction, vehicle management, and fault-tolerant flight and systems control.

■ Weapons and targeting that are compatible with an unmanned aircraft. Technologies include fire-and-forget weapons and human-computer interfaces to support MITL decision authority.
8 Defense Horizons October 2001

arms control agreements—and operational challenges—such as

UCAV integration into the overall battle plan—need to be resolved.

Yet sufficient progress is being made in all of these areas, and meeting the goal of UCAV deployment within the decade seems feasible.

a host of UCAV/UAV controller facilities with each air operations center, burdening theater (and strategic) logistics as well as slowing

command and control. UCAVs should be capable of rapid mission

change, from mission abort orders to redirection to more urgent targets. To do that, they need to incorporate links that can accept mission changes from the central air operations center, AWACS, or other

controlling agency, not solely from system-discrete protocols.

Unmanned combat aerial vehicles are new technologies currently being designed, simulated, and demonstrated. Each of the

services has its own program, as do several U.S. allies and other

countries. In order for the United States to achieve its goal of fielding UCAVs within a decade, significant technical issues must be

solved; for example, the situational awareness picture presented by

current “soda straw” optical systems must be expanded, and the reliability of propulsion and flight control systems must be improved.

Policy questions—such as how UCAVs should be classified under

Defense Horizons is produced by the Publication Directorate of the Institute for National

Strategic Studies (INSS) which publishes books, monographs, and reports on national

security strategy, defense policy, and national military strategy for the National Defense

University. For information on NDU Press visit the Web site at: http://www.ndu.edu/inss/

press/ndup2.html. INSS also produces Joint Force Quarterly for the Chairman of the Joint

Chiefs of Staff; the journal can be accessed at: http://www.dtic.mil/doctrine/jel/

jfq_pubs/index.htm.

The opinions, conclusions, and recommendations expressed or implied within are those of the

contributors and do not necessarily reflect the views of the Department of Defense or any other agency

of the Federal Government.

Robert A. Silano William R. Bode George C. Maerz

Director of Publications General Editor, NDU Press Supervisory Editor, NDU Press

Operational Considerations

■ Mission capability, force integration, and base logistics requirements must be clarified.

■ UCAVs must be integrated into operational command and control and air tasking orders, including the optimum control architecture and

methods for mission changes.

■ UCAVs must be integrated into joint and combined airspace management doctrine/systems without degradation to other users: manned

aircraft, helicopters, artillery and missiles, and UAVs.

■ An operational concept for employing UCAVs in combined operations with allies must be agreed upon, including common operational 

doctrines, combat identification systems, and procedures.

■ UCAV impacts on deployment and sustainment systems must be defined, from global to tactical support.

■ UCAV mission planning requirements must be determined, such as key mission profiles, information requirements, response times, and

onboard/offboard reprogramming requirements.

Policy Issues

■ Research and testing must be a joint service effort with key program leads for both the Air Force and unique Navy applications. The Army

and Marine Corps should be involved throughout as supported services, at least for initial investment programs.

■ Interoperability with NATO and other allies will be crucial to UCAV employment in combined operations. However, UCAVs and other new

systems should seek interoperability in new ways: through incorporation of interface software that allows them to exchange secure data from

other systems, similar to Apple Computer interface software that allows its computers to use PC programs and files.

■ Monitoring arms control implications should be based on the premise that UCAV design has evolved sufficiently to conclude that these

systems are aligned with fighter aircraft and not cruise missiles for the purposes of arms control. UCAVs may eventually be subject to the CFE

Treaty but should not be subject to the INF Treaty. Whether UCAVs would be considered fighter aircraft or a new category of weapon is still undetermined.

■ U.S. export controls that restrict the dissemination of UCAV technologies will work against allied forces acquiring UCAV capabilities but

may be required in some instances for national security reasons. Export controls that apply to emerging UCAV technologies will have to be studied and modified where possible to accommodate technology sharing.

■ UCAV technology investments must be prioritized to align with roles and missions evolution, both within programs for UCAV development

and within the broader context of overall science and technology investments. Cost savings for UCAVs are less likely in the areas of development and procurement but increase significantly in the area of operation and support.