The UAV as sensor platform -- from pioneer to global hawk: the development of UAVs (unmanned aerial vehicles) has witnessed some important successes, but also many failures, and much remains to be accomplished. Armed services want real-time imagery, a quantum reduction in drone attrition rate and operators who do not need pilot ratings. Users also need to decide who is to receive UAV imagery and how it is exploited. (Complete Guide).

From the mid-1960s the use of UAVs for intelligence, surveillance and reconnaissance (ISR) missions has featured in operations over Chechnya, China, the Middle East, South-East Asia and the former Yugoslavia.

Drones (then known as RPVs, i.e., remotely-piloted vehicles) played a comparatively small part in the 1991 Gulf War, because the US services had begun to take a serious interest in their use less than ten years earlier, following losses of manned reconnaissance aircraft over Lebanon.

The principal UAV employed in Desert Storm was the IAI Pioneer, produced under licence by AAI, and operated by the US Marine Corps. Six Pioneer units with a total of around 30 aircraft were deployed: three with USMC ground units, one with the US Army and two on Navy battleships. They flew a total of 1560 hours in 483 sorties, but there were insufficient UAV assets to provide the continuous cover desired.

Two Pioneers were lost to anti-aircraft artillery fire and five to non-combat causes. Of 19 more that suffered combat or non-combat damage, 13 were repaired in the field and six were returned to the AAI factory. The massive reduction in Pioneer availability was an important lesson of the Gulf War, but it appears to have been largely overlooked, perhaps because the Pioneer was regarded as only an interim system.

Other UAVs then employed by the US were the BAI Aerosystems BQM-147A Exdrone and the electrically-powered, hand-launched AeroVironment FQM-151A Pointer. Five Pointer systems with a total of 20 aircraft were deployed to the Gulf (some by Federal Express) to 'serve with USMC and Army units. The Pointer was very reliable, but its range of only five kilometres, its lack of GPS, its black-and-white video camera and difficult handling in high winds restricted its usefulness. If the ground war had been prolonged, Egypt's jet-powered Teledyne Ryan (now Northrop Grumman) Model 324 Scarab would also have been pressed into service.

Allied Force

The Kosovo operation of 1999 brought some more capable UAVs into play. The US services employed two new types: the Air Force's General Atomics RQ-1 Predator and the Army's IAI/TRW Hunter, while the Navy continued with the well-proven Pioneer, now jointly supported by IAI and TRW.

America's UAVs provided target-location data and near real-time battle damage assessment for Nato's Combined Air Operations Center (CAOC) in Italy. In addition, US Navy UAVs conducted surveillance of surface ships and coastal areas.

However, the only UAVs in the area at the start of Operation Allied Force was a German Army Bombardier/ Dornier CL-289 unit, the 100th Drone Battery, which was based in Macedonia from the end of 1998. This situation arose because US Air Force Predators (deployed to Hungary in late 1998) had been withdrawn due to icing problems. Following the first Nato air strikes on March 24,1999, the Predators returned, operating from Tuzla AB in Bosnia and Petrovec airport in Macedonia, where the US Army sent some IAI/TRW Hunters. These were later moved to Albania, where the Central Intelligence Agency had earlier based its General Atomics Gnat-750s. The French Army deployed CL-289s to Macedonia, and the British Army for the first time deployed the BAE Systems Phoenix.

The US Marine Corps employed ship-based IAI/TRW Pioneers for surveillance of naval vessels operating from Montenegro, and to provide targeting information for Boeing AGM-84 Slams fired from P-3Cs.

The jet-powered CL-289 had the advantage of a short transit time, but could not be retasked in flight. Its Zeiss Krt 8/24D camera provided excellent still imagery, which could be passed to Nato's Combined Air Operations Centre (CAOC) in Italy by e-mail or high-quality fax. The Predator's colour video imagery was also highly regarded by Nato planners.

Both the Predator and the Hunter could transmit near real-time imagery to ground stations by means of the Pentagon GBS (Global Broadcast System), and this won popularity with CAOC. European systems may not have always received the attention they deserved.

The availability of UAV imagery was limited in relation to the number of strike sorties (up to 300 per day), and introduced new problems. Following the accidental bombing of civilian targets, it was ruled that the identity of targets of opportunity found by pilots of combat aircraft had to be confirmed by a second source, such as an airborne Fac (forward air controller) or from UAV imagery. However, at America's insistence, the latter type of confirmation could be provided only by Nato's air commander at CAOC, not by a Fac at the UAV ground station. At times the shortage of airborne Facs and UAVs in the area led to long delays in target confirmation, with obvious consequences.

Satellite links made American near real-time imagery widely available, but this created the risk of micro-management from Brussels, to the frustration of field commanders. In the future, Washington may likewise interfere with the day-to-day running of operations.

Attrition

This first multi-national employment of UAVs demonstrated an attrition rate that was on an order higher than that for manned aircraft. The Serbs claim to have shot down 25 UAVs over Kosovo alone, and others were destroyed over Serbia and Montenegro. The best available estimate on the Nato side appears to be that a total of 27 UAVs were lost in the course of Operation Allied Force, including six in accidents.

The combat losses are believed to consist of nine by the US services (five Hunters, two Predators and two Pioneers), five German CL-289s, two French CL-289s and three Sagem Crecerelles and two British Phoenix.

Factors increasing attrition included the Serbs' experience in dealing with UAVs during the previous five years, topographical restrictions on UAV launch sites and entry routes, and unsafe operational techniques.

For example, German CL-289s were reportedly launched at the same time each day, facilitating interception. Knowing the likely entry route, the Serbs could position an Mi-8 with a door-mounted 7.62 mm machine gun to attack the UAV. This led to the bizarre situation of UAVs being given fighter cover! Some UAVs are believed to have been attacked with shoulder-launched Sams, leading to the idea that future drones should have flare-dispensers.

Many lessons were learned over Kosovo, including the need for long-range UAV's if only to overcome the diplomatic problems of basing units in neighbouring countries that feared retaliation from Serbia.

US Developments

Ever since air-launched Teledyne Ryan AQM-34 Firebees were first employed over Vietnam in August 1964, the US has led in long-range UAVs. It may be noted that the sortie-based loss rate over Vietnam was approximately four per cent, and that the use of ISR Firebees was terminated in 1978, although their use as targets continues.

In the 1980s the US purchased Israeli UAVs as an interim measure and planned more ambitious domestic developments;including a phased series of endurance drones, which would exploit increasing levels of stealth technology.

Tier I is the Rotax-engined General Atomics Gnat-750, which first flew in 1989. The air vehicle has a unit cost of $1.2 to 1.8 million, depending on sensor fit, and the ground station is reported to cost between $ 5 and 6 million.

From 1994 the Gnat-750 has been employed by the CIA in flights over the former Yugoslavia, operating from airfields in Albania and Croatia. A batch was sold to Turkey in 1993, and two air vehicles may well have been acquired by the UK. The series has been further developed into the Gnat-XP and the Ignat, and the latter (which has five external hardpoints) is in production for an overseas customer.

Tier II is represented by the General Atomics RQ-1A Predator medium-altitude endurance UAV. It might be characterised as an enlarged Gnat with a more powerful Rotax engine. The baseline version is reported to cost around $ 2 million with a $ 350 000 sensor package mounted in a Versatron/ Wescam Skyball ventral turret. Maiden flight took place in 1994 and it was first deployed for operations over Bosnia in 1995. This series has now performed over 25 000 flight hours; including nine combat deployments to the Balkans and South-West Asia.

The Predator has GPS and is routinely controlled by pilot-rated US Air Force officers, if necessary using Kuband satellite links for over-the-horizon operations. It has also been controlled from a submerged submarine, the crew of which were able to watch real-time EO/IR imagery from the drone.

Standard equipment consists of two colour video cameras, a flir and a Northrop Grumman ZPQ-1 Tesar (tactical endurance synthetic aperture radar). The Predator is the only unmanned reconnaissance system in the US inventory capable of providing day/night all weather near real-time video imagery worldwide.

General Atomics also offers the Lynx radar, developed in co-operation with Sandia Laboratories. Lynx gives a resolution of 3 metres at 160 km range, but can also provide a resolution of 0.1 metres over a reduced area. Lynx is available as a Cots (commercial off-the-shelf) item.

General Atomics is believed to have completed 72 Predators for the US Air Force, US Navy and CIA. Last March the company was awarded a contract for a further seven for the Air Force, with an option on seven more. Italy is to acquire five Predators (with an option on three more), of which four are to be assembled locally by Meteor.

Under a technology demonstration programme sponsored by Eucom (US European Command) into the effects of attacks on chemical warfare facilities, it is planned to track the resulting plume by means of sensors mounted on a Predator and on small Finder UAVs carried by the Predator. The Finder is being developed by the US Naval Research Laboratory.

The Predator B is a growth version of the RQ-1 with a Honeywell TPE331 turboprop engine and increased wingspan. It offers a 50 per cent greater payload and almost double the cruise speed, giving much shorter deployment and repositioning times (e.g., from the Balkans to South-West Asia). The first of three prototypes had its maiden flight last February. One of the prototypes is to be equipped with a Williams FJ44 turbofan.

Tier III was to have been a large, stealthy UAV, but this programme was cancelled in view of its unacceptably high cost. In its place the US launched two intermediate projects: the stealthy Tier III-Minus in the form of the Lockheed Martin/Boeing RQ-3A DarkStar (which first flew in 1996, but was terminated three years later) and the Tier II-Plus Northrop Grumman RQ-4A Global Hawk.

Global Hawk

The RQ-4A (see cover photo) is a high altitude endurance UAV, powered by a Rolls-Royce AE3007H turbofan, and capable of a maximum endurance of 42 hours. It is also designed to respond to an emergency by self-deploying over 8350 km in 14 hours, then remain on station for a further 22 hours at over 60 000 ft before continuing for five more hours to land at a forward operating base.

Global Hawk first flew in 1998, and so far five have been completed, of which one crashed following the accidental transmission of a flight termination signal. The programme is currently in the EMD (engineering manufacturing development) phase, which runs until 2003, but the Lrip (low-rate initial production) contract is due to be signed in November. This will generate two aircraft per year, although this rate is likely to be increased. Unit production flyaway cost is estimated as $15.3 million.

Standard equipment includes a Recon/Optical high-resolution digital optical camera and a Raytheon Integrated Sensor Suite (ISS), combining an EO/IR sensor (a Raytheon thermal imager and a Kodak digital CCD camera), and a Raytheon Sar/MTI radar. The latter provides a resolution of one metre in the wide-area search mode, covering a ten-kilometre wide strip running parallel to the flight path, and offset by 20 to 200 km. In this mode it can cover more than 100 000 sq km in 24 hours. Resolution can be improved to 0.3 metres in the spot mode, searching a two-kilometre square.

The Global Hawk has an aspect ratio of 25, and a maximum lift/drag ratio of 33:1. It has been flown for a distance of 25 000 km, a duration of 31.5 hr, and to a height of 66 400 ft. Interestingly, mid-air relights are not possible. In 1999 a Global Hawk flew from Florida to Portugal and back, without refuelling. In April this year one self-deployed from Edwards AFB in California non-stop to RAAF Edinburgh, South Australia, in a 23.4-hour flight of almost 14 000 km. The series has now completed more than 1000 flight hours. A further demonstration deployment is planned for next year, in this case to Germany, probably leading to Global Hawk's debut at Berlin's ILA-2002 air show.

It is anticipated that the Global Hawk will attain initial operational capability in 2003 at Beale AFB, California, alongside the U-2 that it may eventually replace. The current Block 5 RQ-4A is due to be superseded by the Block 10 with two underwing payload pods, and later by the Block 20 with a larger wing, more powerful engine and a larger payload capacity.

Plans for further developments include an increase in electrical power, and the introduction of an improved radar, most likely the Northrop Grumman/Raytheon MP-Rtip (Multi-Platform -- Radar Technology Insertion Program). It has been proposed that the improved radar should also provide a limited air-to-air capability, since Congress is interested in using Global Hawk in drug-interdiction. Pentagon officials are talking of operating 30 examples of a dedicated signals intelligence version, in addition to 48 standard Global Hawks.

Northrop Grumman currently lacks authorisation to market the aircraft, but the Australian Defence Ministry has already announced that it will seek price and availability data from the Pentagon, with a view to signing a contract for up to six Global Hawks in 2004/2005, and first delivery in 2007. The company is meanwhile studying with Eads a `Eurohawk' version with European sensors.

US Army

The US Army has suffered a long series of UAV setbacks, from the Aquila to the Outrider. The service currently operates one TRW/IAI Hunter system, but this is to be withdrawn, once the AAI RQ-7A Shadow 200 is established in service.

At the end of 1999, AAI (a subsidiary of United Industrial Corporation), teamed with Raytheon, was selected to supply the Army's TUAV (Tactical UAV). The first tour Lrip Shadow 200 systems for initial operational testing and evaluation (IOT&E) have been delivered, and in April the Army exercised its option for four more. Despite accidents in trials, the Army plans to acquire 36 additional systems over the next four years, each with three air vehicles.

The Shadow 200 is launched from an inclined rail by a hydraulic catapult, and lands automatically by means of Sierra Nevada's Tals (Tactical Automatic Landing System). Its principal sensor will be the Northrop Grumman TUAVR (tactical UAV radar), derived from the Tesar used in Predator, and generating both Sar and MTI imagery.

The Shadow 200 is a lighter derivative of the Shadow 400, which is similar in size to the AAI-built Pioneer, and has been purchased by the South Korean Navy. The Shadow 600, as operated by Romania, is the largest of the series, with a twelve-hour endurance.

US Navy

Following experience with the rail-launched IAI/AAI Pioneer (of which four systems are still in use), the US Navy developed a requirement for a VTUAV (vertical take-off and landing UAV) that could operate from a shipboard helicopter pad, regardless of wind direction. The VTUAV will also be required to operate from unprepared landing zones close to the battle area. It is to carry a 90-kg payload and loiter for three hours at 200 km radius and at heights of up to 200 000 ft.

In 1998 the US Navy funded a three-month test programme involving the Bombardier CL-327 Guardian, the Bell Helicopter Textron Eagle Eye tilt-rotor, and the SAIC (Science Applications International Corp) Vigilante, an unmanned version of the two-seat Ultrasport 496 kit-built helicopter.

In February 2000 Northrop Grumman was awarded a $ 93.7 million 42-month EMD contract for the Model 379 Fire Scout, based on the four-seat Schweizer 330SP helicopter and powered by a Rolls-Royce Model 250 turboshaft. This was followed in May 2001 by a $14.2 million Lrip contract.

The Fire Scout VTUAV has an avionics suite that includes GPS navigation, a laser-designator and an EO/IR sensor for which Northrop Grumman's Electronics Sensors & Systems Sector is teamed with IAI/ Taman. An attractive feature of Fire Scout is that a great deal of development flying can be carried out with a safety pilot on board.

A late entry in the VTUAV contest was the Sikorsky Cypher II, a further development of the baseline ducted-fan Cypher, with the addition of wings and a ducted propeller. The US Marine Corps ordered two prototypes under the designation Dragon Warrior, but lost interest when problems arose with the drive system. It is understood that the US Army Night Vision Labs will now use these vehicles as sensor testbeds. Tethered flight tests began in June.

Another VTOL project is the Frontier Systems A160 Hummingbird, two examples of which are being constructed under Darpa (Defense Advanced Research Projects Agency) funding in order to establish the feasibility of long-endurance VTOL UAVs. The A160 is intended to achieve an endurance of more than 40 hours.

A more conventional approach to endurance UAVs appears to be planned for the US Navy's MRE (Multi-Role Endurance) vehicle programme. Small risk-reduction contracts were placed with Martin and Northrop Grumman in April 2000.

The US Navy's Program Executive Office for Cruise Missiles and UAVs is also responsible for the Northrop Grumman BQM-145A Medium Range UAV programme, which was terminated in 1993, following cancellation of its Advanced Tactical Airborne Reconnaissance System payload. First flight nonetheless took place in 1997, and the six vehicles built were used for a variety of tests. The jet-powered drone is still marketed as a means to provide high quality electronic imagery of heavily defended enemy territory.

The low-cost BAI Aerosystems BQM-147A Exdrone has been built in hundreds, and is still operated by the US Army and the US Marine Corps. The latter is upgrading some Exdrones to Dragon Drone standard, which includes a 32-bit unified autopilot, an Inframetrics MILCAM-XP thermal imager, an ALST laser rangefinder and a new ground station. Dragon Drone is being used by the US Marine Corps in advanced warfighting experiments. BAI Aerosystems has recently been awarded a contract from NRL to manufacture the Dragon Eye mini UAV system for the US Marine Corps Warfighting Lab.

Although developed primarily as a high altitude research UAV, the General Atomics Altus has recently been employed in medium altitude signals intelligence and surveillance trials off the California coast in support of US Navy and Marine Corps operations.

Israel

The Malat division of IAI traces its experience back to the IAI Scout of 1976. This led to the Scout II of 1981, and four years later the IAI/AAI Pioneer, of which over 200 examples were purchased by the US Navy.

The Ranger (another twin-boom, single pusher engine design) was developed through the co-operation of Swiss companies Ruag Aerospace (former F+W) and Oerlikon Contraves together with Israel Aircraft Industries to suit European environmental conditions and meet that country's tactical UAV requirements.

In late 1995, a contract was signed to purchase four Ranger systems for the Swiss Army (designated ADS 95), each with seven air vehicles and two ground control stations. In 1999 the Finnish Ministry of Defence ordered one Ranger. The deployment in Finland will take place in fall 2001 while the deployment in Switzerland was completed in 1999.

The Ranger system has thus far completed over 1500 flight missions with more than 2200 total flight hours.

The Ranger employs an automatic take-off and landing system based on a laser tracker, and the UAV's can be launched either by hydro-pneumatic catapult (no pyrotechnics) or conventional wheeled take-off. The recovery is by skids or a wheeled landing.

An electro-optical TV/Flir payload provides for both day and night intelligence capabilities. A Sar sensor is in the making, and other sensors for mine detection, gamma radiation measurement and Elint missions are supposedly in an advanced project stage.

Basic system characteristics include a range of 180 km, a maximum altitude of 15 000 ft and an endurance of up to 8 hours with a single ground station.

Following the successful use of the landing System in Switzerland, Belgium and Finland, last May C.O.E.L. was awarded a contract by Ruag Aerospace for the development and delivery of next-generation optronics.

The IAI/Malat series of single-engined drones led in 1988 to the Searcher, a multi-role, long endurance, high capacity UAV that provides day/night real-time imagery. The improved Searcher II is in service with the Israel Defense Force (IDF), and is still in production for foreign customers. An example was shown at Le Bourget last June equipped with an IAI/Elta AWL/M-2055 Sar, the first such installation in a UAV of that size.

In 1987 IAI first flew the Impact, a twin-engined push-pull configuration, which served as the prototype for the Hunter. The US Army and Marine Corps adopted the Hunter in 1989 as their short-range system. It was subsequently ordered by the Belgian Army, which uses an automatic take-off and landing system similar to that employed for the Swiss Ranger. The Hunter has also been used by the French Army in a five-year trials programme (including operations over Kosovo) to evaluate its all-weather target acquisition and laser designation capability.

Interest in long endurance UAVs led to the medium altitude IAI Heron, which first flew in late 1994. In the following year it made a 51 hr 21 min flight carrying a 200 kg payload. The Heron was used as testbed for the Elta EL/M-2022U maritime surveillance radar, which weighs approximately 40 kg, detects small ships at around 120 km, and can track 32 targets while continuing to scan. The Heron TP is a much heavier (3000 kg) turboprop derivative with a further increase in wingspan.

Late last year the Indian Army signed a $ 300 million contract for up to ten Searcher IIs and at least four Herons. This followed a smaller contract in 1997 for a 16-aircraft batch of Searchers and Hunters.

Combining the long-span wing and the tail surfaces of the Heron with the fuselage of the Hunter produced the E-Hunter (Endurance-Hunter), which is intended to compete with the General Atomics Predator. The E-Hunter first flew in 1995.

At Le Bourget in June, IAI showed the lightweight Aerosky, developed by Aeronautics Unmanned Systems, with which IAI has recently signed an agreement to co-operate on UAVs.

The smallest of the IAI/Malat range is the 80 kg Eye View, which is distinguished visually by its inverted vee-tail. It first flew in 1996 and is one of the few UAVs ever demonstrated in flight at a major international air show (Fidae-98 in Chile). Eye View was designed to carry the Tamam Plug-in Optronic Payload (Pop), which combines daylight and infrared sensors. Malat is also developing a larger (130 kg) Eye View 2 derivative to accommodate heavier payloads. Air vehicles designed by IAI/Malat are now in service in fourteen countries.

Reports from Israel suggest that the Eye View was designed as a rival for the 55 kg Mini-V developed by the Silver Arrow division of Elbit Systems (recently merged with El-Op, which produces payloads for UAVs). The Mini-V is bungee-launched from a rail mounted on the roof of the control vehicle, and recovered by parachute. Payload options include the Controp ESP-1H, a gimballed, stabilised EO system including a CCD video camera with a 50 to 300 mm zoom lens, and a 16 mm wide-angle still camera.

On an increasing weight scale, the next air vehicle in the Silver Arrow range is the 155 kg Sniper. It is powered by a 28.3 kW Wankel-type powerplant produced by the UK-based UAV Engines, which is owned by Elbit. The Sniper is rail-launched and recovered by means of a parachute and air bags, although a wheeled undercarriage is available for training.

The principal Silver Arrow endurance UAV appears to be the single-engined Hermes 450 (earlier designated 450S), which has a maximum flight duration of 20 hours. It is now operational with the IDF, as part of the service's modernisation programme. The airframe is largely of composite construction, and the Hermes 450 has an endurance of 20 hours. It is designed to carry such payloads as the Northrop Grumman Tesar synthetic aperture radar, E1-Op Compass, and the Controp DSP-1. The Hermes 450 was shown at Le Bourget in satellite communications configuration, with broadband systems to transfer real-time imagery to ground control stations. A differential GPS system is available for automatic take-off and landing. Whereas the Indian Army is receiving UAVs from IAI/Malat, the Indian Air Force has reportedly ordered the Silver Arrow Hermes 450.

The twin-engined Elbit Systems Hermes 1500, which is being developed jointly with the IDF, is much heavier (the Hermes model number indicating approximate gross weight in kilograms). The Hermes 1500 is, in fact, considerably heavier than the Predator, E-Hunter and Heron. Payload options include the Elta EL/M-2055 Sar. Elbit is responsible for the common ground control station (CGCS), which is based on that for the Hermes 450. Maximum endurance is 40 hours. The Hermes 1500 first flew in 1998. It has recently been announced that the wingspan is to be increased by 50 per cent to 15 metres, to enable it to meet IDF requirements.

France

In 2000, Matra BAe Dynamics, Aerospatiale Matra (now part of Eads) and CAC Systemes formed a joint venture to combine their UAV interests. In the very short-range category (i.e. ranges less than 70 km and endurances less than four hours), this brought together the CAC Fox AT and the AeroVironment Pointer. In the short-range tactical category (70 to 300 km range, and five to ten hours endurance), the partnership brought together the Canadair/Aerospatiale CL-289 Piver (Programmation, Interpretation, Visualisation d'Engins de Reconnaissance) and the Eurodrone Brevel.

In the medium-altitude long endurance (Male) category (200 to 1000 km range and 10 to 30 hr endurance) it introduced the Eagle 1 and 2, respectively based on the IAI/Malat Heron and turboprop Heron TP. In the high-altitude long endurance (Hale) strategic intelligence category (transcontinental range and an endurance of more than one day), effort was to be concentrated on the Aerospatiale Matra Fregate project, designed to fly for over 30 hr at up to 60 000 ft.

In May it was announced that France's DGA (Delegation Generale pour l'Armament) had chosen the turboprop-powered Eads Eagle (derived from the IAI Heron TP) for the French Air Force's Male role, in preference to America's Predator, which had been promoted by Sagem. It is anticipated that up to five Eagle systems will be purchased. The air vehicle will be equipped with Sar/MTI radar, TV, flir and a satellite communications link.

Sagem has marketed several foreign UAVs as alternatives to indigenous designs, but has also developed the Crecerelle. This has been used for several years by the French Army, which has recently ordered a communications jammer version. The Sperwer is a major improvement, with longer range and endurance, and is distinguished by its twin vertical tails. The Sperwer has been adopted by the Netherlands and Denmark, Sweden and France. Sweden operates a cold climate derivative under the name Ugglan (Owl). The three-nation export total is currently 60 air vehicles. Last year Sagem unveiled its hand-launched TMD3 lightweight UAV.

Where the name Sperwer once designated a single aircraft type it now refers to a family of drones, since two new versions -- the LE for long endurance and the HV for high velocity -- were unveiled at the 2001 Paris Air Show. Sagem's aim was to enable current users of Sperwer aircraft to opt for other applications and performance without needing to change either the existing infrastructure or ground station. Thus, not only is the same basic fuselage retained for the two new models to enable them to use the same catapult, but so are the internal guidance electronics, avionics and downlink systems.

The Sperwer LE thus features a new 6.5-metre span wing. Its twelve-hour endurance was sought not for longer ranges but rather for longer loiter times. It can act as a data relay station, detect artillery fire and carry missile launch sensors. This bird should have its maiden flight by the end of 2001.

The Sperwer HV, for its part, is a longer-term project. The airframe is subjected to more severe modifications since it will be powered by a Microturbo TRS 18-1 jet engine. Intended for high-speed (740 km/hour) low altitude penetrations and laser target designation, it is equipped with canards to enhance controllability. Springing off the catapult rail at about 100 knots, it will have a 200-kilometre, line-of-sight range.

Dassault has embarked on a series of UAV technology demonstrators (the Petit/Moyen/Grand Duc series), and in July 2000 flew the stealthy twin-jet AVE (Aeronef de Validation Experimental). However, the company's emphasis appears to be on unmanned combat air vehicles, rather than ISR.

France is cooperating with Germany in the Eurodrone consortium, in which Matra BAe Dynamics (now MBDA) is teamed with STN Atlas. The principal Eurodrone project to date is the Brevel, of which the German Army is buying 16 systems with a total of 80 air vehicles, under the KZO designation. The Brevel is a stealthy reconnaissance drone with a high-definition thermal camera jointly developed by STN Atlas and Zeiss. The Tucan is a simpler, non-stealthy endurance UAV that is being offered for export.

In 2000, STN Atlas Elektronik received a concept definition contract from the German Procurement Agency (BWB) for an ESM (electronic support measures) drone known as the Fledermaus (Bat).

On a more modest scale than the KZO, the German Army in 1996 evaluated a number of lightweight observation drones under the Luna programme. In 1997 the Bavarian EMT company, which had earlier developed a target drone, was awarded a contract for four pre-production UAVs, designated Luna X-2000. The drone is bungee-launched from a rail and recovered by parachute. An unusual feature is that (having a sailplane-like wing) it can glide for a considerable distance, allowing its acoustic signature to be eliminated over the targeted area. Although not yet formally in service with the German Army, a prototype flew 27 sorties over Kosovo.

Another potentially important German UAV is the Dasa Dornier (now Eads) Seamos, a VTOL radar platform that employs a coaxial rotor system (based on that of the Gyrodyne QH-50 drone helicopter). Seamos is intended to equip the German Navy's forthcoming K130 corvettes.

Miscellany

Austria's principal contribution to UAV development appears to be the lightweight Camcopter, manufactured by Schiebel of Vienna. It has been evaluated by the US Army and the German Defense Ministry as a means of detecting mines, and by a US Joint Interagency Task Force in operations from the Coast Guard cutter Valiant. The Camcopter has also been purchased by the Egyptian Navy.

China is known to have copied the Ryan Firebee under the name Changkong, and at the Zhuhai airshow late last year some details were revealed of the current production version, with GPS/INS navigation. It was said to have a range of 2500 km and a ceiling of 57 500 ft. Beijing Wisewell Avionics presented its Shark-2 and Merlin-2 surveillance UAVs, and the Nanjing Research Institute exhibits included the W-30 and W-50, with endurances of four and six hours respectively. Guizhou Aviation Industry, which is primarily concerned with two-seat derivatives of the MiG-21, is developing the stealthy, twin-jet WZ-2000.

The Czech Republic's principal product in the UAV field is the Sojka (Jay), which was designed by the Air Force Research Institute 030 in Prague and has been in service with the Czech Army since 1995. It was later marketed by Hungary's AviaTronic. The standard payload is a black-and-white CCD video camera and an Intertechnique Camelia infrared line scanner.

Italy's Meteor is part of the Alenia Difesa group, owned by the State agency Finmeccanica. Meteor is probably best known for its target drones, which have been widely exported, but it also produces the propeller-driven Mirach 20 and 26 and the jet-powered Mirach 150 reconnaissance UAVs. All three types are in service with the Italian Army. Following the Kosovo conflict, Meteor received additional orders for the Mirach 26 and 150. The company will assemble most of the Predators bought by Italy, build the control station and act as payload systems integrator. Meteor is also developing the medium-range Mirach 2000.

Although Japan is not yet among the technological leaders in UAV development, it may be noted that the drone produced in the world's largest numbers is reportedly the Yamaha R-50 crop-spraying helicopter. There may be military uses for such a machine.

Russia's reconnaissance UAVs go back at least as far as 1963.The jet-powered Tu-243 was developed for the export market, and the further improved Tu-300 was unveiled at the Moscow Air Show of 1995.

The Yakovlev Pchela-1 is a short-range TV-platform. It entered service in 1997 as part of the Stroy-P reconnaissance system, which is believed to have been used in Chechnya. The same piston engine was used for the Kamov Ka-37 helicopter project, which appears to have been superseded by the Ka-137 with a more powerful Hirth engine from Germany. Sterkh is another reconnaissance system that is based on a piston-engined vehicle, reportedly the Yakovlev Shmel (Bumble-bee).

In recent years Yakovlev has shown models of a series of UAV projects, from the Colibri of 1992 to the Expert and tilt-rotor Albatros exhibited in model form at Farnborough last year. The Ukraine's NPS produces the Remez-3, a canard configuration UAV that made its Western debut at Eurosatory in 2000, and is in service with the Ukrainian Army and one foreign customer.

The Kentron division of Denel produces the Seeker UAV family, which has been in service in South Africa for fifteen years. Operators include Algeria and the UAE. Denel's Cumulus unit is responsible for the Goshawk multi-sensor gyro-stabilised payload. The upgraded Seeker II has digital avionics, an improved communications link, better performance and the 410 mm diameter Goshawk 400 payload with optional laser ranging. The daylight video camera is unchanged, but Kentron's Kenis third-generation flir has been added. Parachute recovery and an electronic surveillance payload are available. Navigation is by DGPS/INS.

The Ate (Advanced Technologies & Engineering) Vulture UAV was designed specifically to support South African artillery. It appears that the production model will be derived from the 25 per cent larger Super Vulture, with an endurance of eight hours, a new ground control station, a new datalink and a Kentron/Cumulus Goshawk payload. It is proposed to use rocket-assisted take-off and a laser-guided automatic landing system, opening the prospect of maritime operations.

Although Britain has produced various target drones, its achievements in the field of reconnaissance UAVs have been limited. The Flight Refuelling Raven and the Meggitt Defence Systems Phantom and Spectre are all relatively modest propeller-driven aircraft.

The first of 198 BAE Systems Phoenix UAVs entered service with the British Army in 1998, but the system appears to have had more than its fair share of problems. Upgrades currently planned include a more powerful engine and the addition of Symetrics/ARINC IDMs (Improved Data Modems) to the ground stations, enabling them to send imagery directly to the cockpits of fixed- and rotary-wing ground attack aircraft.

Although much remains to be done in improving conventional UAVs, America is already investigating quantum leaps toward both micro-UAVs and large but stealthy air vehicles. It is hoped to discuss both of these lines of development in a future issue.

A Selection of Current Unmanned Aerial Vehicles

Designation       Manufacturer            Overall               Overall
                                           Length                Span
                                           [m]                   [m]

A160 Hummingbird  Frontier Systems         5.18                   n/a
                                          (rotor blades)

Aerosky           IAI                       n/a                  4.48

Altus 2           General Atomics,         7.20                 16.86
                  Aeronautical Systems

ASN-206           Catic                    3.84                  6.04

BQM-145A          Northrop Grumman,        5.49                  3.20
                  Ryan Aeronautical

Camcopter         Schiebel                 2.68                   n/a

Changhong IC      People's Republic of     8.47                  7.53
                  China

CL-289/CL-289     Bombardier/Dornier       3.51                  1.31
Piver             (Eads)

CL-327 Guardian   Bombardier               1.83                  4.05

Crecerelle        Sagem                    2.75                  3.29

Cypher            United Technologies,      n/a                   n/a
                  Sikorsky Aircraft

Dragon Drone      BAI Aerosystems          1.86                  2.47

Dragon Warrior    United Technologies,     3.05                  1.83
                  Sikorsky Aircraft

Eagle I           Eads, IAI                8.94                 16.30

Eagle II          Eads, IAI               13.00                 26.00

Eagle Eye         Bell Helicopter          5.46                  4.63
                  Textron

E-Hunter          IAI Malat                7.53                 15.39

Exdrone           BAI Aerosystems          1.86                  2.47
(BQM-147A)

Eyeview 1 / 2     IAI Malat                2.93                  3.96

Fox AT1/AT2       CAC-Eads                 2.77                  3.66

Global Hawk       Northrop Grumman,       13.53                 35.42
RQ-4A Tier II     Ryan Aeronautical
plus)

Gnat 750          General Atomics,         5.49                 10.67
(Tier I)          Aeronautical Systems

Hermes 1500       Silver Arrow             9.39                 15.00

Hermes 450        Silver Arrow             6.10                 10.52

Heron             IAI Malat                8.60                 16.61

Heron TP          IAI Malat               12.00                 23.01

Hunter            IAI Malat, TRW           6.89                  8.90

I-Gnat            General Atomics,         6.34                 12.86
                  Aeronautical Systems

Ka-137            Kamov Design Bureau      5.30                   n/a

KZO / Brevel      STN Atlas/Eads           2.26                  3.41

Luna X-2000       EMT                      2.26                  4.42

Micro-V           Silver Arrow             2.74                  3.66

Mirach 150        Finmeccanica, Meteor     4.69                  2.10

Mirach 20         Finmeccanica, Meteor     3.60                  4.15

Mirach 26         Finmeccanica, Meteor     3.78                  4.72

Model 379 Fire    Northrop Grumman         7.01                   n/a
Scout (RQ-8A)

Pchela 1          Yakovlev Design          2.77                  3.26
                  Bureau/Kulon
                  (Sys. Integr.)

Phantom           Meggitt Defence          1.52                  2.44
                  Systems

Phoenix           BAE Systems               n/a                  5.49

Pioneer           IAI/AAI                  4.24                  5.12

Pointer           Aerovironment            1.83                  2.74
(FQM-151A)

Predator (RQ-1)   General Atomics,         8.23                 14.84
                  Aeronautical Systems

Predator B        General Atomics,        10.36                 19.51
                  Aeronautical Systems

Ranger            Ruag Aerospace/IAI       4.60                  5.70

Scarab (Model     Northrop Grumman,        6.16                  3.35
324)              Ryan Aeronautical

Seamos            Eads                     2.93                  6.10

Searcher II       IAI Malat                5.85                  8.56

Seeker II         Denel/Kentron            4.44                  7.00

Shadow 200        AAI                      3.75                  4.27
(RQ-7A)

Shadow 400        AAI                      3.82                  5.15

Shadow 600        AAI                      5.18                  7.47

Shmel Yak-61      Yakovlev Design Bureau   2.77                  3.26
(BumbleBee)

Sniper            Silver Arrow             3.78                  5.21

Sojka             VTULaSTV                 3.81                  4.08

Spectre           Meggitt Defence          2.71                  3.26
                  Systems

Sperwer           Sagem                    3.51                  4.21

Sperwer LE        Sagem                    3.51                  6.49

Sperwer HV        Sagem                    4.11                  3.35

Super Vulture     Advanced Technologies &  3.89                  6.52
                  Engineering

Tu-243            A.N. Tupolev ANTK        8.29                  2.26
(VR-3 Reys-D)

Tucan             STN Atlas/BAE            2.26                  3.41

Vulture           Advanced Technologies &  3.11                  5.21
                  Engineering

Designation        Body        Launched Weight   Powerplant
                   Diameter    no booster
                    [m]          [kg]

A160 Hummingbird   n/a          1814             Piston engine, +300 hp

Aerosky            n/a           70              n/a

Altus 2            .76           816             1 x Rotax twin turbo

ASN-206            n/a           222             Rocket Booster

BQM-145A           n/a           907             1 x Teledyne CAE
                                                 F408-CA100 t-fan.

Camcopter          n/a            68             1 x 2-stroke, 15 hp

Changhong IC       .58           245             1 x WP6 tj.

CL-289/CL-289      .40           240             1 x BMW RR T117 + solid
Piver                                            booster

CL-327 Guardian    .88           349             1 x Williams WTS 117-5

Crecerelle         n/a           120             1 x reciprocating
                                                 engine

Cypher            1.90           136             UAV Engines AR 801

Dragon Drone       n/a            43             1 x 100 cc, 2-stroke,
                                                 heavy fuel

Dragon Warrior     n/a           109             n/a

Eagle I            n/a          1150             1 x Rotax 914

Eagle II           n/a          3600             1 x P&W Canada PT6A tp

Eagle Eye          .76          1021             1 All Model 250-C20B

E-Hunter           n/a           953             2 x 64 hp Dual

Exdrone            n/a            41             1 x 8 hp 2-stroke
(BQM-147A)

Eyeview 1 / 2      n/a           104             1 x 25 hp Engine

Fox AT1/AT2        .46           113             1 x Limbach 22 hp
                                                 reciprocating

Global Hawk       1.46        11 612             1 x All AE3007H
(RQ-4A Tier II                                   turbofan.
plus)

Gnat 750           .76           513             1 x Rotax 582
(Tier I)

Hermes 1500        .73          1497             2 x Rotax 914, 100 hp
                                                (ea) rotary

Hermes 450         .52           449            1 x UEL AR-80-1010 52
                                                hp rotary

Heron              .85          1098            1 x 100 hp

Heron TP           n/a          3502            1 x 1200 hp Turboprop

Hunter             n/a           726            2 x 64 hp Dual

I-Gnat             .76           635            1 x Rotax 914 gasoline

Ka-137            1.19           279            1 x Hirth 2706 P05, 65
                                                hp

KZO / Brevel       .37           161            1 x 30 hp reciprocating

Luna X-2000        n/a            30            2-cylinder 2-stroke
                                                engine (5kW)

Micro-V            .21            50            2 x 4 hp, 2-stroke

Mirach 150         .37           345            1 x Microturbo TRS 18-1

Mirach 20          .34           170            1 x 26 hp

Mirach 26          .37           200            1 x 28 hp

Model 379 Fire     n/a          1157            1 x Rolls-Royce
Scout (RQ-8A)                                   250-C20W

Pchela 1           .31           130            1 x Samara / Trud P-032
                                                re., 32 hp

Phantom            n/a            29            1 x 2-stroke, 75 cc

Phoenix            n/a           175            1 x WAE 342, 2-stroke,
                                                25 hp

Pioneer            .37           210            1 x Sachs SF2-350

Pointer            n/a          3.60            1 x Astro 15 electric
(FQM-151A)

Predator (RQ-1)   1.22           862            1 x Rotax 914 gasoline

Predator B         n/a           903            1 x ASE TPE331-10

Ranger             n/a           274            1 x Goebler-Hirt 42 hp
                                                2-stroke
Scarab (Model      n/a          1077            1 x Teledyne CAE
324)                                            373-8C

Seamos             n/a          1120            1 x All 250-C20

Searcher II        n/a           426            1 x 73 hp Rotary

Seeker II          n/a           240            1 x Limbach, model
                                                H550E

Shadow 200         .34           138            1 x UAV Engines Ar 741
(RQ-7A)                                         rotary

Shadow 400         n/a           203            1 x UAV Engines AR-741

Shadow 600         .46           264            1 x UAV Engines AR-801
                                                rotary

Shmel Yak-61       n/a           129            n/a
(BumbleBee)

Sniper             .52           155            1 x 38 hp

Sojka              n/a           145            2-cylinder 2-stroke
                                                engine (22kW)

Spectre            .46           159            1 x TTL-WAE 342

Sperwer            n/a           149            1 x 70 hp 2-stroke

Sperwer LE         n/a           n/a            1 x 70 hp 2-stroke

Sperwer HV         n/a           n/a            1 x Microturbo TRS 18-1

Super Vulture      .88           309            n/a

Tu-243             n/a          1397            1 x Izotov TR-3-117
(VR-3 Reys-D)                                   turbojet

Tucan              n/a           160            n/a

Vulture            .70           125            1 x TTL-WAE 342

Designation             Payload

A160 Hummingbird        Sar, EO/IR

Aerosky

Altus 2                 Scientific (various manufacturers)

ASN-206                 Day/night

BQM-145A                Programmable (Tra)

Camcopter               CCD camera (various manufacturers)

Changhong IC            R/c (NAI)

CL-289/CL-289           Day camera, optical camera, IRLS
Piver

CL-327 Guardian         Various (FSI, various)

Crecerelle              Flir (Sagem)

Cypher                  EO, Flir, etc. (various manufacturers)

Dragon Drone            Day color TV, laser (BAI Aerosystems)

Dragon Warrior          EO/IR

Eagle I                 Customer defined

Eagle II                Customer defined

Eagle Eye               Mine detect, EO/IR (various manufacturers)

E-Hunter                TV & IR, custom (IAI Tamam)

Exdrone                 Range finder TV, IR (various manufacturers)
(BQM-147A)

Eyeview 1 / 2           Day/night imager (various manufacturers)

Fox AT1/AT2             R/c, program, track. (CAC Systemes/various)

Global Hawk             Sar/MTI, EO, IR (Raytheon)
RQ-4A Tier II
plus)

Gnat 750                Day TV, Flir (Wescam)
(Tier I)

Hermes 1500             EM, TV, Sar (various manufacturers)

Hermes 450              TV, Sar (various manufacturers)

Heron                   TV & IR, custom (IAI Tamam)

Heron TP                TV & IR, custom (IAI Tamam, various)

Hunter                  TV & IR, (IAI Tamam)

I-Gnat                  EO, IR or Sar (Wescam)

Ka-137                  Various (various manufacturers)

KZO / Brevel            Flir (STN Atlas)

Luna X-2000             CCD camera (various manufacturers)

Micro-V                 CCD camera, Flir (various manufacturers)

Mirach 150              TV, IR, EW, Sar (various manufacturers)

Mirach 20               TV or Flir/Elint (Meteor)

Mirach 26               TV, LLTV, Flir, Elint (various manufacturers)

Model 379 Fire          EO/IR, laser designator (various manufacturers)
Scout (RQ-8A)

Pchela 1                TV/IR linescanner (Kulon)

Phantom                 Camera or line scanner (Meggit)

Phoenix                 Infrared imager

Pioneer                 TV & Flir (IAI Tamam, Versatron)

Pointer                 Radio command (JR)
(FQM-151A)

Predator (RQ-1)         EO, IR, Sar (Northrop Grumman, Wescam)

Predator B              EO, IR, Sar (General Atomics, Wescam)

Ranger                  EO/IR sensor (II Tamam)

Scarab (Model           Program command (Tra)
324)

Seamos                  Radar, EO, Flir (Dornier)

Searcher II             TV & Flir (IAI Tamam)

Seeker II               n/a

Shadow 200              Various (various manufacturers)
(RQ-7A)

Shadow 400              Customer defined

Shadow 600              Various (various manufacturers)

Shmel Yak-61            Day/night imager (various manufacturers)
(BumbleBee)

Sniper                  TV, Flir (various manufacturers)

Sojka                   CCD camera, IR (various manufacturers)

Spectre                 CCD camera, Flir, EW (various manufacturers)

Sperwer                 Flir, EW, Sar (Sagem)

Sperwer LE              Flir, EW, Sar (Sagem)

Sperwer HV              Sar, linescanner

Super Vulture           n/a

Tu-243                  Simultaneous TV (Aist-M) IR (Zima-M)
(VR-3 Reys-D)

Tucan                   IR/TV

Vulture                 Optronic day sight (M-Tek)