They fly and they crash, but defence ministries keep on pouring cash into unmanned air vehicles (UAVs), despite a litany of programme failures and embarrassing flops. Defence ministries in general, and the US Department of Defense (DoD) in particular, continue to fund UAV programmes because they are on the cusp of a technology breakthrough which could affect radically the way in which future conflicts will be fought.

The US Army deployed one Israel Aircraft Industries Hunter UAV tactical reconnaissance system during its Force XXI exercise in April to examine the "digitised battlespace".


Longevity of interest

Because of the system's effectiveness, the "Blue Force" commander involved in the exercise had to deploy a large proportion of his forces in trying to locate and engage it - he also changed his operational plan because he believed that the intelligence provided by the Hunter had compromised the original blueprint.

Military forces have had a longstanding interest in UAVs, but it is only recently that this interest has threatened to translate fully into operational systems earmarked to carry out those tasks deemed too "dull, dangerous or dirty" for crewed aircraft.

It is perhaps no surprise that a UAV of Israeli origin proved of such utility. The Israeli armed forces have been the most successful in using UAVs in the surveillance and reconnaissance roles for over a decade.

Speaking at a recent UAV symposium in London, organised by the Royal Air Force Air Warfare Centre and Operational Requirements Staff, Mike Foley, business-development manager, force projection, with Boeing's Defense and Space Group, pointed to the longevity of interest in UAVs, if not their deployment.

In the 1970s, the company worked on the Compass Cope long-endurance reconnaissance remotely piloted vehicle for the US Air Force. Over the span of the six-year programme, the UAV was flown for flight durations of up to 16h at altitudes of up to 63,000ft (19,200m). Foley notes, however, that "-the programme was discontinued before production - there was no customer-funding support".

Undeterred, Boeing went on to develop the Condor high-altitude, long-endurance UAV for the US Defence Advanced Research Projects Agency. The Condor programme was to run from 1981 to 1991 and, over the decade, was to achieve a world record for an unmanned, unrefuelled flight of over 58h, as well as reaching altitudes of more than 67,000ft. Foley notes wryly that the programme was disbanded. "Again, there was no customer-funding support," he says.

Boeing was not the only US manufacturer to dabble in pilotless projects. Lockheed had developed a supersonic reconnaissance drone to be operated in association with its SR-71, called the D-21, but its career was inauspicious.

The problem was that, while the air-vehicle technology was relatively mature, many of the critical subsystems needed to turn projects into operational equipment were not ready. It is only now that the necessary computer, communications and sensor technologies are becoming available in packages small enough to be genuinely applicable to sophisticated UAVs.

Col Mike Francis, director of architecture and integration with the DoD's Defense Airborne Reconnaissance Office (DARO), identifies these "enabling technologies" as computing power, communications bandwidth and the global-positioning system.


"Stovepipe" solutions

Another problem was that these programmes were "stovepipe" solutions, with military forces having no over-arching operational doctrine within which they fitted, and within which the information obtained could be distributed.

The Compass Cope, Condor and D-21 projects were all intended for strategic reconnaissance within the doctrinal frame of the Cold War. As Air Vice Marshal Chris Coville, the UK's Assistant Chief of the Defence Staff, Operational Requirements, points out: "The Cold War was an aberration. We are now back to normal and are dealing with a new security landscape." It is within this "landscape", says Coville, that UAVs must be considered.

There can be no doubt that UAVs in the widest possible sense have now captured the imagination of a swathe of the defence community, both within the industry and within some elements of the armed services, covering a host of proposed applications.

In broad terms, there are two types of UAVs undergoing exploration - those which are equipped with sensors, but without any weaponry, and those which will carry ordnance. The latter are now increasingly being referred to as uninhabited combat air vehicles (UCAVs).

Defining a UAV is not easy. One simple response suggests a controlled air vehicle which does not require any onboard crew, but this definition also fits such items as cruise missiles. There are those within the UAV community who argue that cruise missiles fall within a particular class of combat UAV, but others disagree.

Tony Wilson, chief of operational analysis at British Aerospace, describes four classes of vehicles which provide useful indicators as to the breadth of a workable UAV definition - remotely piloted vehicles (which he calls "man with a joystick"), remotely controlled vehicles ("observe and assign, then re-assign"), remotely monitored vehicles ("read a newspaper and intervene/ override in an emergency") and the autonomous unmanned air vehicle ("launch and forget").


UAV roles

Lt Col John Wilson, of the UK Ministry of Defence's (MoD) Directorate of Land Warfare, delineates roles for sensor-only-equipped UAVs as "surveillance, reconnaissance, target acquisition, electronic warfare, communications and data relay and combat deception".

Several of these functions are referred to by some as ISTAR applications - intelligence, surveillance, target acquisition and reconnaissance. ISTAR platforms can be crewed or uncrewed. The UK MoD's Advanced Stand-off Radar project, for instance, could be considered to be a crewed ISTAR asset.


Air doctrine

Whether crewed, or uncrewed, ISTAR assets fall within an air doctrine which is evolving to meet Coville's "new security landscape". Within the UK's evolving air doctrine, and common to many Western air forces, including the US Air Force, are such themes as increased stand-off capabilities, more precision and mobility, greater exploitation of information and communications (coupled with the political imperative to minimise casualties on both sides), as well as reduced collateral damage.

A similar set of doctrinal parameters are spelled out by Lt Col Wilson, who says: "Future warfare will be focused around a quick victory, avoiding attrition, with attacks carried out at distance, and with an emphasis on preserving one's own forces."

The fundamental element contributing to all of the above is an emphasis on "manoeuvre", rather than attritional, warfare, where a fighting force will not attempt to destroy all of the enemy's fighting material. The aim is rather to disrupt the enemy's ability to deploy and use its forces in a coherent fashion, therefore undermining the capability to fight.

Wilson also flags up one of the key changes in the nature of warfare during the 20th century - the reduced density of the battlefield. With the improved accuracy of air-launched and surface-to-surface weaponry, there has been a doctrinal shift toward dispersed forces, to avoid presenting multiple targets in a limited area. The ability to locate, identify and target enemy assets over a large area therefore becomes of ever-increasing importance.

All these desired attributes within the doctrine which is emerging are dependent on the timely availability of intelligence imagery and data, and this is one of the reasons behind the growing interest in UAVs.

Grp Capt Roger Gault, responsible for operational doctrine and training at the RAF's Air Warfare Centre, cautions that, in considering the link between technology and doctrine, there is "-a temptation to use technology simply because it is available, but you should establish the doctrine first".

In part, it was exactly this failure which contributed to projects such as the Compass Cope and the Condor not crossing the bridge from development into operational service. Boeing and the user community had followed technology paths because they were available, rather than to meet existing or emerging doctrinal requirements.

The US defence department has gone to great lengths to avoid repeating such errors, although its latest burst of enthusiasm for UAVs has encountered other problems.

The creation of the DARO, the result of Government initiatives set in train in 1993, was, as Francis points out, to provide "single-point control of all airborne reconnaissance programmes", including "endurance UAVs for surveillance support to military operations".

Previous projects had tended to be single-service driven and managed, rather than oriented to multi-service use. As well as being divisive, with each service scrambling for resources, the single-service approach was of a "stovepipe" nature - predicated on a standalone, rather than an integrated and distributed, approach.

The UK MoD, in the wake of the prolonged GEC-Marconi Phoenix reconnaissance-UAV project for the British Army, has created a tri-service group, led by the Air Systems directorate, to create a coherent approach to UAV acquisition and operations.

The Phoenix experience exemplifies what can go wrong with what is an apparently simple requirement for a tactical reconnaissance and surveillance UAV. At the doctrinal level, it also reflects many of the pitfalls of a single-service programme.

An injudicious selection of the basic air vehicle, coupled with a lack of growth potential in the engine, led to problems as the army requirement expanded to reflect changing operational requirements. The Phoenix, originally designed to be operated in the cold climate of the Central European Front, was suddenly more likely to be deployed out of area in climates demanding a hot-and-high performance, which the air vehicle lacked.


Datalink problems

In developmental terms, GEC also ran into problems with the datalink for the air vehicle. The army had originally promised that a Westland Lynx would be made available as an airborne testbed for the datalink.

The aircraft, however, was never forthcoming, while availability and flight-pattern restrictions on the range also hampered datalink testing. GEC sources also admit that the company's project management on the Phoenix left a lot to be desired.

As ever, with the benefit of hindsight, it is easy to identify military and industrial misjudgements of the demands of developing and procuring even a relatively "simple" tactical UAV. With the creation of the tri-service group, the MoD appears to be learning from experience.

The UK is not alone in struggling with UAV development. Francis, of the US DARO is candid about the problems and issues presented by many of the six reconnaissance UAV projects which DARO controls. These include:

- the Alliant Techsystems Outrider short-range tactical UAV has suffered from both "system integration and testing delays";

- the Israel Aircraft Industries (IAI) Pioneer short-range UAV needs an improved engine;

- the IAI Hunter tactical UAV suffers funding problems;

- the General Atomics Predator has a problem of "asset availability";

- Lockheed Martin's DarkStar high-altitude endurance UAV crashed on its second flight, resulting in changes to some flight-control algorithms. The vehicle's landing gear is also being redesigned;

- Teledyne's Ryan Global Hawk high-altitude long-endurance UAV for DARO has a problem with "software handling and integration".

More significant than the variety of programmatic teething troubles which DARO faces is the breadth and scope of the UAV programmes which it now oversees. All of the DARO projects are intended to provide the "warfighter", to use US DoD parlance, with "information superiority". The basic driver is to know as much about your enemy's forces as possible - from the tactical to strategic arenas - while denying them the same access to your own forces.

The Hunter, Pioneer and Outrider provide the short-range tactical element within the DARO framework - all using either electro-optic (EO) or infra-red (IR) sensor packages. A general-consensus definition of a tactical UAV is one which operates at altitudes of up to 25,000ft with an endurance of up to 12h.

All three DARO systems have ranges of more than 185km (100nm). The Pioneer was bought as an interim system in 1986 and has been flown for more than 15,000h, including 835 combat sorties. Its eventual successor is intended to be the Outrider - 62 systems are expected to be bought, each with four air vehicles. Production-standard air vehicles are due to be delivered from fiscal year 1998.


Predator position

The Predator fulfils the medium-altitude endurance-UAV role and the vehicle has been deployed in Bosnia on 219 missions. The objective is for 16 systems to be purchased, again each with four air vehicles. The Predator has an operational radius of 925km, with an a maximum endurance of more than 20h.

The Global Hawk is a stand-off, high-altitude endurance UAV, offering a step increase in performance in comparison with the Predator. The air vehicle has an endurance of up to 40h at a maximum altitude of 65,000ft, with a 5,550km radius of operation. In addition to its EOand IR sensors, the Global Hawk is also intended to carry a synthetic-aperture-radar (SAR) sensor for stand-off surveillance. The first flight of the air vehicle id expected in October.

The Global Hawk is seen as either a complement to, or potential replacement for, the Lockheed U-2.

The DoD intends to field the DarkStar low-observable UAV alongside the Global Hawk. This vehicle would use its low-observable characteristics to penetrate enemy or threat airspace, rather than relying on operating at stand-off ranges for self-protection. The DarkStar will be fitted with SAR and EO sensor packages. The air vehicle would have an operational radius of 925km, with a 9h endurance at altitudes of up to 50,000ft.

Those UAVs sit within the DoD's so-called Tier I to Tier III classes, with Tier IV being space-based assets. While the USA believes that it can afford to fund the development and procurement of systems to fulfil all of the operational niches within these tiers, other, less-affluent, defence ministries will need to be more selective, particularly where high-performance systems are concerned.

Despite the apparently technically ambitious nature of the DarkStar and the Global Hawk programmes, the UAV community is confident that this class of system can be fielded in the near term. There is much more animated discussion about the timescales within which UCAVs will enter service.

The UCAV moves beyond the traditional realm of the UAV in potentially supplanting, rather than supporting, crewed-aircraft operations. Larry Birckelbaw, a programme manager with the USA's Defence ADvanced Research Project Agency (DARPA), describes the attraction of the UCAV as being for "high-risk/high pay-off missions". The role of the UCAV would be to provide all-weather suppression of enemy air defences, or for air strikes against well-defended, high-value, targets.

The increasing proliferation of such extended-range air-defence systems as the Russian S-300PMU (SA-10 Grumble) and the likely export of the S-300V (SA-12A/B Gladiator/ Giant) poses a threat to crewed strike aircraft.


Low tolerance

The ability to deploy a UCAV in the defence-suppression role supporting a crewed strike, or a fleet of UCAVs operating fully autonomously in various roles, has obvious attractions. Not least, it avoids the possibility of another Scott O'Grady shoot-down incident - the DoD is becoming more conscious of the low tolerance of the general population to combat casualties. Armand Chaput, UCAV team leader with Lockheed Martin Tactical Aircraft Systems, identifies the advantage of the UCAV at the policy level as providing planners with the guarantee of "no risk of pilot loss or capture".

Removing the pilot from an air vehicle offers clear design advantages, allowing the aircraft to be designed for the mission, not around the pilot. DARPA identifies the major advantages: "Eliminating the vertical tail reduces weight and drag, and reduces the radar signature. It allows for a shortened fuselage and shape for optimum drag and efficiency."

Taking these together, DARPA argues that a UCAV would have a "-dramatically reduced acquisition cost" against a comparative crewed design. The UCAV would also be some 40% smaller than the crewed equivalent, with "inherently reduced observables".

At an operational level, Chaput offers the advantage of mission planning "not limited by physiological limits or constraints". This provides the potential to exploit new tactical environments such as long missions, high-tempo operations and those which require high manoeuvrability.


UCAV potential

The USAF and US Navy are examining the potential for UCAVs. The Israeli air force and the RAF are also interested in researching this area. The RAF will examine UCAVs as a possible successor to its Panavia Tornado GR4 strike aircraft. The GR4 is expected to be replaced around 2015, although there are those close to the project who harbour substantial doubts as to whether UCAV technology will be mature enough to fulfil all of the required roles.

In the USA, both the air force and navy are considering demonstrator projects, using the Lockheed Martin F-16 and McDonnell Douglas F-18, respectively, to explore technology requirements. These could either feed into all-new airframe designs, or be used as the basis for converting F-16s and F-18s into UCAVs for operational deployment.

It is also a distinct possibility that late models of the DoD's Joint Strike Fighter programme will be configured as UCAVs - providing operators with a potential "mix-and- match" fleet of crewed and uncrewed aircraft.

Even UCAV enthusiasts admit that there is a range of conceptual, technical and operational issues which needs to be addressed - making the problems of UAVs to date pale into near insignificance.

There is an enormous gulf between deploying a UAV armed only with an EO sensor package and a UCAV carrying an offensive payload. There is also the issue of just how much "autonomy" a UCAV would have. Chaput suggests several concepts.

The UCAV could be flown by an operator from a command centre covering both the transit-flight and target-engagement phases. Alternatively, one operator could control the UCAV during the transit phase, with another operator aboard, for instance, a Northrop Grumman E-8 Joint Surveillance Target Acquisition Radar System aircraft controlling the strike phase of the mission. A third option would be to have one operations centre control the transit phase, with another ground centre - nearer the combat area - controlling the UCAV beyond the forward edge of battle.

The absolutely critical element in all of this is at which point, if any, does the UCAV require what Chaput describes as "consent or authorisation". Does the operator behave like a pilot in a virtual or synthetic cockpit, effectively flying the UCAV by proxy, or is he or she a systems manager only entering into the command loop at critical decision points - ie, for weapons release or target engagement?

In the same way that UAVs have begun to impinge - and will increasingly do so - on operational concepts for intelligence, surveillance and reconnaissance, then UCAVs will do the same for air-combat operations in the strike and air-defence/air-superiority roles.

In addition to Chaput's ground-based-operator approach, other UCAV proponents are considering whether the vehicles could be operated as part of a mixed "swarm" including crewed aircraft. Richard Weeks, systems integration manager with the UK's Defence Evaluation Research Agency, identifies "-the principle of the swarm approach as limiting the risk to the crewed platform". While the swarm concept would inherently expose the UCAV to greater risk than that facing a crewed platform, Weeks believes that combat UAVs are unlikely "-to be cheap enough to be considered truly expendable."

While the near-autonomous UCAV appears to be an ambitious goal, it does offer one critical advantage to the UAV/UCAV community in an area which may prove to be its Achilles heel. The more that a UCAV is capable of acting independently of its control centre, then the fewer will be the demands which are placed on the communications infrastructure. Communications systems, or bandwidth, threaten to be the critical choke point for both UAV and UCAV operations.

The electro-magnetic spectrum, broad though it might be, is effectively finite. There is already a battle for bandwidth among civil- and military-aircraft operators, and an increasing preponderance of UAVs can only exacerbate this. Europe is already viewed by some military users as "a busted flush" in this area.


Infrastructural demands

UAVs, be they short-range tactical, or high-altitude long-endurance, will place only growing demands on the communications infrastructure - not only for command and control inputs via datalink, but, more importantly, for the near-real-time delivery of sensor imagery. It is the latter which will place extraordinary pressures on both line-of-sight (LOS) and beyond-LOS bandwidth.

Sqn Ldr Andrew Powell, who works for the UKMoD's Operational Requirements branch, paints a potential "nightmare scenario" of UAV and UCAV operators all trying to use the same communications infrastructure at the same time, and all using different formats and communications protocols, with the information being distributed in an "untailored" fashion. Such a scenario would bring the communications infrastructure crashing down around the ears of the operators, with disastrous results if a military campaign were being undertaken at the time.

Standardisation and data compression are the key concerns. There is little point in a UAVacquiring valuable intelligence imagery if it cannot be delivered to a potential user in time. One other area where there is continuing research is that of semi-automated image processing. DARPA is working on UAV image-processing packages which would enable only relevant imagery to be datalinked to ground-based analysts. This is based around the use of automatic target-recognition software.

Despite the daunting list of challenges, such as the problems of bandwidth, the need to create an integrated command, control, communications and intelligence network capable of distributing data to the appropriate sites, the requirement for substantial levels of artificial intelligence in autonomous vehicles, and the need for a coherent operational doctrine, UAVs and UCAVs look set to play an increasing role among the options available to military planners.

The combination of force and budget reductions, coupled with an increased sensitivity to combat casualties and collateral damage, will provide the necessary impetus for the further acceptance of UAVs and UCAVs into the military.

They will also, to some extent, need to be accepted by the civil air-traffic-control community - but that, perhaps, is another story

Dull, dirty and dangerous roles are likely to be the forté of UAVs and UCAVs in the future as military planners look to meet the demands of conflict in the 21st century.

Source: Flight International