UAV – Unmanned Aerial Vehicles

Jürgen Erbe

To begin with it is necessary to provide a definition, which is indeed not easy to formulate since the choice of name is not unambiguous at all. The system to be dealt with is UAV, which, according to German definition are propelled, unmanned aerial vehicles. There was obviously a (tacit) national and international agreement on this acronym. In the past, terms such as RPV (Remotely Piloted Vehicle) or flight robot were also in use. UAV is now regarded as a reusable aerial vehicle with self-propulsion capable of carrying diverse payloads, which flies either completely autonomously or remotely, controlled.
The fundamental difference to cruise or guided missiles, for instance, is that UAV can return after their mission. This does not exclude their employment as so-called »combat drones«, however. And here it becomes apparent that the term »drone« is still preserved in German linguistic usage while in Anglican usage the term UCAV (Unmanned Combat Aerial Vehicle) is more customary. The term »drone« was introduced in the German Army with the CL 89 in the 1970s. The CL 289 drone reconnaissance system was later successfully employed in the Balkans. Here, nothing will be renamed. The German Air Force uses this term exclusively for its target drones.
The UAV used today have been developed from target simulation drones, however. Drones were employed in Vietnam for the first time. Thus, about 3,500 drone sorties were conducted for reconnaissance and jamming purposes. After all, already 84 percent of the drones are said to have returned at that time. After the Vietnam War the drones were not paid much attention anymore. Only Israel pursued the development of so-called RPV and employed them successfully in several wars (1973, 1982). Only the positive experiences made with them in the second Gulf War led to a change of the hitherto neglected UAV technology. But then, the development was carried on at a breath-taking pace – primarily in the U.S.A.
It was above all the »Predator« of the U.S. Air Force that was convincingly employed in the Balkans in the last phase of 1999 and subsequently in Afghanistan. Of decisive importance was the long endurance in high altitudes in reconnaissance missions with high resolution SAR (Synthetic Aperture Radar) as well as worldwide reception of target data in quasi real time. When the practical implementation of the attempts at gaining information superiority were already recognizable in this kind of use, the Iraq conflict made it clear to some extent what the U.S. armed forces understand by »Network Centric Warfare (NCW)« and which important role the UAV play in reconnaissance tasks and soon also in communications as well as in weapon effects in the not too distant future. »Predator« and »Global Hawk« were the systems that were mainly employed.
UAV systems are being linked with high hopes and great expectations. But the complexity of the system and above all the cost factor are often overlooked. There will be great chances, of course, which got to be coolly capitalized on. Besides, it will probably surprise some of our readers to learn about the extent of experience the Bundeswehr has gathered with UAV in missions which is necessary to make use of in future systems. According to their tasks, UAV can be distinguished as follows:

  • UAV for support tasks (relay functions, gathering of general data, etc.)
  • UAV for reconnaissance purposes with imaging or signal acquisition sensors
  • UAV for air transport
  • UAV for combating the enemy within the scope of electronic countermeasures
  • UCAV (Unmanned Combat Aerial Vehicles) for lethal engagement of ground and air targets.

Classification of UAV
Category Name Range Operational Altitude Endurance Payload
HALE High Altitude Long Endurance > 1,000 km > 15,000 m 24-40 h 1,000 kg
MALE Medium Altitude Long Endurance > 500 km < 15,000 m 24-48 h 400 kg
TUAV Tactical UAV 10-200 km up to 7,600 m 3.5-40 h 4-200 kg
MUAV Mini UAV < 10 km up to 250 m up to 2 h -
MAV Micro UAV < 10 km up to 250 m 1 h -

Components of a UAV System

In any case, a UAV system is more than just only an autonomously flying or remotely controlled aerial craft carrying a payload. It consists of the following sub-components: aerial craft, propulsion, control and navigation equipment, payload as well as ground organization.
Meanwhile, there exist an infinite number of different carrier systems ranging from palm-size micro UAVs to the 11.6 ton »Global Hawk« (see Table »Selected Platforms«). In the foreseeable future there will thus certainly be a carrier system available for any kind of requirement. With all the euphoria some limits are overlooked, however.

UAVs Used as Sensor Platform
The most frequent case of an employment of a UAV is certainly that of a sensor platform. When in the past it was possible to accommodate only a maximum of two sensors simultaneously aboard the craft, it is no problem today to accommodate several sensor systems thanks to the miniaturization of the electronic modules. Modularity is a magic word here, too. It is not only restricted to the exchangeability of sensors, but it means also the integration of several ones at the same time. Studies show, however, that the simultaneous use of sensors is set clear limits, too. Reasons for this are restrictions of potential carrier systems through payload, available space or the energy available for the operation of the sensors. According to the common view held by industry and relevant authorities the simultaneous use of actively radiating radar sensors (all-weather capability, if required) and signal detecting reconnaissance components was rejected at this point of time. A modular concept is only suitable for relatively small sensors; larger sensor systems must be integrated into the carrier platforms.

UAVs as Weapon Carriers
The employment of UAVs as so-called UCAVs (Unmanned Combat Aerial Vehicles) would also seem to be possible. There are three possibilities for their arming: as carriers of standoff weapons, as carriers of kinetic weapons, and as carriers of warheads.
The »Predator« of the U.S. Air Force featured prominently as a carrier of air-to-ground guided missiles (AGM 114 Hellfire) in Afghanistan and in the Iraq war. UAVs with warheads are being advanced. And so the Israeli »Harpy« combat drone is being tested. The German »Taifun« combat drone is in a critical survival struggle due to certain technical problems. It is equipped with a warhead, which is capable of engaging armored targets. The advantage of an employment of UAVs vis-à-vis the employment of conventional guided missiles is that the target is engaged only after intelligent reconnaissance and after authorization by the ground station, respectively. Otherwise, the UAV flies back and is employed in another way or function. In the long run, however, a UCAV will be an intelligent supplement and not an alternative armament system.

Ground Organization
onThe ground organization is often an overlooked or underrated system with respect to effort and cost. It normally consists of the following components: launch and landing system, ground control station, transmitting/receiving station, remote ground receiving stations as well as servicing and maintenance modules.
In addition to that there will be the respective, often very specialized expert personnel. While small devices are often very cost-effective (LUNA, ALADIN of the German Army), the bigger and more complex systems are very expensive. In any case, the general statement according to which UAVs are very cost-effective does not apply in such indiscriminate way.

Selected Platforms in Comparison

Experiences gathered by the Bundeswehr

Reconnaissance by the Army
Although it is generally and automatically asserted by critics that the Bundeswehr was always lagging behind particularly in regard to equipment, this is often not true on closer inspection. This goes also for the use of drones/UAVs. Already in the early 1990s the drone system CL 289 was procured for the artillery for target acquisition. It is, however, strictly program-controlled and delivers reconnaissance data in a range of up to 170 km with a flying speed of about 740 km. In doing so, it covers a distance of approximately 400 km in 30 minutes. The system underwent its crucial test in the Kosovo conflict during which 18 drones were employed over Kosovo, launched from Macedonia. But five of them were lost, however. By 2005, the CL 289 will get a performance improvement, which will allow it to cover a larger area.
In this year, the field artillery of the German Army will be equipped with the »KZO« target locating remote controlled unmanned aerial vehicle, another UAV for reconnaissance purposes. The system will allow conducting zone/area, target, and post-strike reconnaissance up to a depth of 65 km during day and night. It has a flight endurance of approximately 3.5 hours at variable altitudes ranging from 300 to 3,300 m and depending on the mission and the threat posed by enemy air defence. The airspeed is about 150 km/h. It is possible to change in flight a flight program fed in prior to the launch. Beginning in this year up to 2007, the artillery will receive six systems.
In addition, this branch is to also get the LUNA airborne unmanned close reconnaissance equipment. The field artillery has already established a composite system in the meaning of »command and control – reconnaissance – effect« by having linked the available reconnaissance means (hitherto the CL 289, now KZO and COBRA (Counter Battery Radar) – introduction in 2004) as well as UAV ALADIN and the Armored Self-propelled Howitzer 2000 and the MARS Medium-range Artillery Rocket System with the ADLER Command Control and Fire Direction System. One could speak of a »mini« Network Centric Warfare here.

German UAVs in Operations
After the employment of the CL 289 drone in Kosovo, an experimental model of LUNA was employed which was developed by the German EMT Engineering Company Dipl.-Ing. Hartmut Euer – supported by study assignments of the Federal Office of Defence Technology and Procurement – and advanced to production stage. Meanwhile LUNA has been employed successfully in Afghanistan for months. Over there, the ISAF forces are presently using seven systems.
The LUNA UAV is a self-controlling high-performance catapult-launched motor glider. With a wingspan of 4.17 m and a length of 2.24 m, the launch weight is about 30 kg (depending on the sensor equipment). The typical reconnaissance speed of 70 km/h is reached by a two-cylinder twin-stroke engine (power rating of 5 kW) with a generator for accumulator charging and power supply. The flight endurance, which depends on payload, mission profile and wind conditions is up to four hours. With a range of the radio relay data link of about 80 km and a permissible flight altitude of up to 3,000 m above sea level, LUNA has to be classified among the TUAVs. The handling including the recovery after the parachute landing and the re-launch (after only 15 minutes) are very simple. The modular surveillance sensor systems are available as payloads.
Also procured by the EMT Company through the ESB channel (mission-related immediate field requirements) for the German Army for employment in Afghanistan was a mini UAV ALADIN (imaging airborne reconnaissance drone for close ranges). Of this system, three are presently fielded with the German forces. MUAV ALADIN is launched from the hand and is an electric motor glider. With a launch weight of 3 kg and a wingspan and length of 150 cm each, a payload of 0.3 kg and an operational altitude of 30 to 200 m, a speed of 45 to 90 km/h and a flight endurance of well over 30 minutes, the operational range is more than 5 km. It is possible to increase this range by employment relay UAVs. This, by the way, applies in the case of LUNA, too. A color zoom video camera or optionally an IR camera are used as reconnaissance sensors.

UAV Companies in Germany

EADS with a Broadly Diversified Portfolio
With its Dornier subsidiary company the EADS (European Aeronautic Defence and Space Company) was not only the first enterprise which has successfully dealt with drones – at first with the CL 89 and later the CL 289 and target drones – but today this combine is in a position to offer the entire spectrum of UAVs, be it micro or mini UAVs, MALE or HALE UAVs. Although it was still a 1:1 scale wooden model back at the International Air Show in Berlin, a prototype of the »Global Hawk« UAV landed at the Nordholz Naval Air Base on 15 October 2003. This unmanned aircraft, which is the largest that has ever existed and which is meanwhile being fabricated by Northrop Grumman in serial production for the U.S. Air Force under the designation RQ-4A, was equipped with ELINT (Electronic Intelligence) systems by EADS to demonstrate that this UAV is possible to be employed as a replacement for the Breguet Atlantic maritime patrol and ASW aircraft. Following the decision of Defence Minister Peter Struck according to which UAV reconnaissance by Navy and Air Force has to be relinquished, it can only be hoped for »Global Hawk« to be employed in NATO AGS (Alliance Ground Surveillance) operations. And Germany will, as was announced by Mr. Struck in his press conference on 13 January, participate in this NATO project at any rate.
With the diversified portfolio of EADS and international activities it is certain, however, that there will always be a solution in case of national requirements arising at a later date – with the production taking place abroad, however.

Rheinmetall Defence Electronics
Hitherto it was STN ATLAS Elektronik where the UAVs were developed. The reorganization of this company (after its split into BAE Systems and Rheinmetall AG) also entailed a renaming. The flying equipment »KZO« (target locating remote controlled unmanned aerial vehicle) and the »Taifun« combat drone were dealt with in another passage already. The first »KZO« system is going to be fielded with the troops in this very year, whereas »Taifun« is struggling to survive.
Apart from »Global Hawk« it is above all the Predator UAV, which has become publicly known. Cooperation has been entered upon with its manufacturer, General Atomics, where the system »Predator B« is now offered as an alternative to »Global Hawk«. But here the same applies what has been said earlier: the only chance that presently exists is the NATO AGS project.

EMT Ingenieurgesellschaft Dipl.-Ing. Hartmut Euer mbH
In the 25 years after its foundation, the medium-sized EMT engineering company in the Bavarian town of Penzberg has developed into an innovative supplier of small military unmanned flying equipment for the Bundeswehr. The LUNA and ALADIN UAVs are being employed in Afghanistan. A larger X-13 with a payload of 30 kg is under development just as the MIKADO micro UAV and, as a supplement to it for employment in house-to-house combat, a FanCopter for a soon-to-begin national competition.

Limits

Unmanned carrier systems are very interesting and enticing solutions for military use. It is obvious that UAVs are mainly suitable as carriers for reconnaissance sensors. But aside from limits in the carrier as to space and weight, problems need also to be solved in respect to power supply and, above all, in connection with data transmission and data processing. UAVs are a typical element of the Network Centric Warfare. With all the euphoric reception given to the NCW or as we call it »network conduct of operations«, it is necessary to initially resolve some of the questions regarding the information structure. Otherwise, there is the threat of »infostress«, because NCW relies primarily on information exchange. In this respect starting out with »Mini NCW« in Afghanistan is not a bad test bed at all. Scarce money can sometimes also be a good teacher, but it should not be that scarce after all.

Jürgen Erbe, Special Correspondent of »European Security« for Armaments and Army Subjects and German Correspondent of »Jane’s Defence Weekly«.

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Company Class Platform Weight in kg Wing Span in meters Payload in kg Maximum Altitude in m Endurance in hours Class
Northrop Grumman Global Hawk 11,600 35.4 900 19,000 36+ HALE-UAV
General Atomics Predator B 001 4,500 19.5 680 15,200 25+ HALE-UAV
EADS Eagle II 3,600 26.0 500 13,500 23+ MALE-UAV
Elbit/ Israel Hermes 1500 1,500 15.3 350 9,200 24+ MALE-UAV
EADS Eagle 1,150 16.3 250 7,500 23+ MALE-UAV
IAI/ Israel Heron 1,100 16.6 250 9,200 50+ MALE-UAV
IAI Hunter 730 8.9 110 4,600 12+ TUAV
General Atomics Predator A 690 14.9 200 7,600 40+ TUAV
Elbit/ Israel Hermes 450 450 10.7 n.n. 5,500 20+ TUAV
IAI/ Israel Ranger 275 15.1 45 4,600 5+ TUAV
AAI Corp./ USA Shadow 600 265 6.8 40 4,800 13 TUAV
Rheinmetall Defence Electronics KZO 160 3.4 25 3,500 3,5+ TUAV
EMT/ Penzberg X-13 130 5.1 30 3,100 6 TUAV
EMT/ Penzberg LUNA 30 4.2 4 3,000 3,5+ TUAV