Bolt from a more distant blue: between the two extremes of low-cost guided bombs (see Armada 1/2002) and expensive long-range cruise missiles (3/2001) there exists a need for cost-effective tactical air-to-ground guided weapons that can deliver suitable warheads precisely and from a safe distance against high-value, hardened, mobile or multiple targets by day and night and under all weather conditions. (Airborne Warfare).
Conceptually, the first step in keeping the attacking aircraft outside the range of Shorad systems is to give the warhead fixed wings, a simple guidance system and control surfaces. However, wingspan is then restricted by the proximity of other stores, and lift:drag ratio is limited accordingly. Eads/LFK was a leader in this field, first exploiting the lifting body effect of a rectangular-section submunition-dispenser with the MW2 (Mehrzweckwaffe-2) weapon, which was developed for the German Air Force Tornado IDS. For export purposes the MW2 became the DWS24 dispenser weapon system, which in 1990 was ordered by the Swedish Air Force under the designation DWS39 for use on the Viggen and JAS39. The DWS24 designation referred to the fact that it was designed to carry 24 runway-cratering submunitions.
The DWS39 formed the basis for the Eads/LFK AFDS (Autonomous Freeflight Dispenser System), which in 1998 was ordered by the Hellenic Air Force. The AFDS employs GPS+INS navigation and has a range of 20 kilometres when released at altitude. Perhaps more importantly, it can reach over ten kilometres from low-level release at Mach 0.9, or at an offset of five kilometres, eliminating the need to overfly the target. Carried by an aircraft with a MIL-STD-1553B databus, the AFDS can be targeted at any time prior to launch, otherwise the target co-ordinates are inserted by means of a cartridge on the ground. The AFDS can dispense (laterally) a wide variety of anti-armour and anti-runway submunitions and minelets. Greece has the 24-submunition runway-cratering version. Other options include 96 anti-materiel or area denial submunitions, or 120 anti-tank mines.
Some indication of the potential value of major aerodynamic improvements is provided by the range that may be achieved by glide munitions fitted with high aspect ratio wings, using variable-geometry, to make possible multiple store carriage. For example, the Israel Military Industries (IMI) Modular Stand-Off Vehicle (MSOV) is credited with a range of 100 kilometres, implying a lift:drag ratio around 7.3:1. The MSOV dispenser, which employs GPS+INS navigation, completed its initial development stage in April 1998, when the first demonstration flight test was performed from an Israel Air Force F-16. Possible payloads include 1332 dual-purpose bomblets, 288 BLU-97 CEBs, 42 anti-runway submunitions and an I-1000 unitary penetrator.
Turning to wing kits designed to suit retrofits to standard munitions, the Leigh Aerosystems LongShot high aspect ratio wing adapter kit is predicted to achieve from a height of 30,000 feet a range of 75 kilometres for a Combined Effects Munition (CEM), and 105 kilometres for a Mk 83 bomb, corresponding to lift:drag ratios of 8:1 and 11.5:1 respectively. In a July 2000 test a Boeing BLU-109 Joint Direct Attack Munition (Jdam) equipped with an MBDA Diamond Back wing kit achieved a range of 38.6 kilometres from a release height of 20,000 ft, implying a lift:drag ratio of 6.3:1. For comparison, the Jdam kit alone (with body strakes) gives a range of only 12.9 kilometres from that height.
These wing kits are applicable to a wide range of unitary munitions and submunition-dispensers, including the Mk 80 bomb series and all weapons based on the SUU-64/65/66 Tactical Munitions Dispenser (TMD). The TMD family includes the Alliant Techsystems CBU-87/B CEM containing 202 BLU-97/B CEBs (Combined Effects Bomblets), and the CBU-89/B Gator with a total of 94 BLU-91/B anti-tank and BLU-92/B anti-personnel mines.
The CBU-87/B CEM is designed for release at heights between 200 and 40,000 feet and at speeds from 370 to 1300 km/hr. It employs the SUU-65/B version of the TMD, which has angled fins to induce spin. The fins are released from their retracted position by an aircraft-anchored lanyard that also activates a thermal battery for the optional proximity fuze. The ground crew selects a spin rate of up to 2500 rpm and sets the timer (up to 4.15 seconds) that opens the casing. For high-level release, an Alliant Techsystems FZU-39/B radar proximity fuze is preset to open the casing at heights of between 300 and 3000 feet.
The BLU-97/B CEB submunition is retarded and turned down to the vertical by an attached inflatable decelerator or ballute. It has a downward-firing shaped charge warhead with a casing that breaks into two-gram fragments, and a zirconium ring for incendiary effects. The CEM was used in large numbers in 1999 over Kosovo, where the CEB was also dispensed from the Tomahawk cruise missile and the AGM-154A (discussed later).
The Textron Systems CBU-97 Sensor Fuzed Weapon (SFW), which is based on the SUU-66/B TMD, is one of the principal technological advances in dealing with armoured formations. After the Sensor Fuzed Weapon is released from the aircraft, the TMD casing is stripped off and ten BLU-108s are dispensed. Each is retarded by a parachute, which brings it to a vertical position over the target area. Its rocket motor is then fired, reversing its descent and inducing a spin, which has the effect of radially throwing out four Skeet warheads. The Skeet carries a dual-spectrum infrared sensor, and its spinning causes this device to scan a lenticular-shaped area of ground as it moves outward, initially rising and then falling. On sensing a target, the Skeet fires an explosively-formed projectile (EFP) that can penetrate the upper armour of any tank. The 40 warheads of the SFW cover an area roughly 350 metres long and 200 metres wide. The SFW is designed for release from altitudes of 200 to 20,000 feet and at speeds up to 1200 km/hr.
Tests of the Pre-Planned Product Improvement (P3I) variant of the SFW began in April 2000. The first full-rate production contract was awarded in 1996, the system achieved initial operational capability the following year, and in 2001 Textron Systems was awarded its sixth full-rate production contract, in this case for 300 units totalling $130 million. The current production standard is the Improved SFW, which almost doubles the footprint area of the baseline model. The US Air Force plans to acquire a total of 5000 units, over half of which have so far been ordered. The Textron Systems BLU-108 is also produced for the Raytheon AGM-154B (discussed later).
Aside from the CBU-87/B CEM, Kosovo also witnessed the use of the TMD-based CBU-102(V)2/B, which dispensed BLU-114 submunitions filled with highly conductive carbon-fibre threads to short-circuit Yugoslav electrical grids. At that stage the dispenser was unguided, and had to be released from an F-117 flying below 10,000 feet. Another TMD variant is being developed to dispense flechettes in attacks on targets such as chemical and biological storage facilities. It is envisaged that the TMD series will later be used to dispense the US Army's wide area anti-armour mines, anti-helicopter mines and other future smart submunitions.
In the interim, the US Air Force plans to have 40,000 TMDs (including the CBU-102 series) fitted with the Lockheed Martin Wind-Corrected Munitions Dispenser (WCMD, pronounced "Wick-Mid") tail kit, which employs inertial navigation to steer the munition from a GPS-derived release point to precise target co-ordinates, compensating for wind and adverse weather. This programme stems from experience in the 1991 Gulf War, when the US Air Force was forced by Iraqi air defences to release ordinance from medium/high altitude, with significant loss of precision. Lockheed Martin publicity material refers to an accuracy of 25 metres, but reports indicate that in tests the WCMD has achieved accuracy better than ten metres. The system reached initial operational capability on the B-52 in late 1998. Lacking a GPS receiver and a seeker for terminal guidance, the WCMD is intentionally a low-cost kit, with a unit price currently below $9000. The CEM+WCMD combination first saw operational use in Afghanistan in late 2001.
The discussion has so far been concerned with the results that can be achieved by adding variable-geometry wing kits to standard bombs and dispensers. This approach, exemplified by the Diamond Back and the LongShot, is clearly attractive in budgetary terms, since it makes full use of ordnance that is already in the inventory. However, in principle longer ranges can be achieved by designing a brand-new guided missile, containing a warhead or submunitions from existing ordnance, but without the aerodynamic constraints of an add-on wing kit.
This principle was adapted for the Kentron (Denel) Raptor 1, which was used operationally by the South African Air Force in the 1980s war in Angola, but unveiled for the first time to the public during the African Aerospace exhibition in 1998. It carried a standard 550 kg fragmentation or penetration warhead and had a TV camera in the nose for terminal guidance. Launched from a Mirage F1 at 35,000 feet, its high aspect ratio wing gave the Raptor 1 a range of 60 kilometres. This suggests a rather disappointing lift:drag ratio of 5.6:1, but the true figure may be somewhat better, as the Raptor normally makes a steep dive in the terminal phase. Kentron has subsequently marketed the missile with GPS navigation and an optional imaging-infrared seeker for night operation. Pilots reported to Armada that under certain dusk conditions, strong sun reflections from rivers (when attacking a bridge, for example) could blind the camera and therefore disrupt target tracking. A dedicated anti-radiation version has been mentioned, but there appear to be no reports of export orders. One reason may be that its launch weight of 980 kg makes it unsuitable for lightweight fighters. In the case of an aircraft such as the Mirage F1, the Raptor and its datalink pod take the inboard wing pylons, restricting the carriage of external tanks. A Raptor II was put into production in 1998.
The Raytheon AGM-154 Joint Stand-Off Weapon (Jsow) is aerodynamically a very clean weapon and probably represents the practical limit for glide performance. It began as a US Navy development, aimed at replacing missiles such as the Maverick, Walleye, Skipper, the Rockeye cluster bomb and older laser-guided bombs. The Navy requirement placed a weight restriction of 485 kg on the Jsow so that an AV-8B could land vertically with a missile under one wing. However, it is envisaged that with different warheads the weight will grow to around 680 kg. The Jsow attains a range of 24 kilometres from low-level release and 64 kilometres from high release. On published data, the Jsow appears to have a lift:drag ratio of around 7:1.
In 1991, Texas Instruments (since part of Raytheon) was selected to develop the missile, and in the following year the US Air Force joined the programme, which thus became Jsow. It is currently conceived in three principal forms. The baseline AGM-154A employs GPS+INS navigation and dispenses 145 BLU-97 CEBs, reduced from 202 in the case of the CEM. Deliveries began in 1998, and in the following year this first version of the Jsow was used operationally from US Navy F/A-18s against targets such as air defence radars, armour, artillery and personnel in Kosovo. The AGM-154A was also used in early 2001 against Iraqi radar sites, but produced larger than expected miss distances.
The AGM-154B is still under development. It will employ the same guidance as the -154A, but will dispense six BLU-108s, compared to ten in the case of the SFW. The AGM-154C will have an imaging infrared seeker for terminal guidance and a 225 kg class penetration warhead, either the BLU-111 or the RO Defence Broach. It may be noted that a version of the Jsow with a turbine engine was proposed to meet an Australian requirement (Air 5418), recalling that an AGM-154 with a Williams W-24-8 turbojet was test flown in 1995. A range in excess of 200 kilometres was predicted, although the fuel tankage demands would further restrict payload volume.
The use of rocket motors makes it possible to achieve air-to-ground ranges in the order of 100 kilometres. The point may be illustrated by the case of the rocket-powered Boeing (formerly Rockwell) AGM-130, which provides roughly three times the maximum range of the GBU-15 glide bomb (or Cruciform Wing Weapon) on which it is based. The GBU-15 is available in two versions: the GBU-15(V)1/B with a television camera for terminal guidance, and the -15(V)2/B with an imaging infrared seeker for night operations. Either kit can be fitted to the Mk 84 bomb body or the BLU-109/B penetrator. It was planned to have a submunition version based on the SUU-54 dispenser, but this never eventuated. Development began in 1974, and Rockwell produced over 3000 kits. The US Air Force is currently believed to have around 1500, most of which are to be equipped with Raytheon GPS guidance systems, giving an accuracy of better than five metres without use of the seeker. The GBU-15 has a range of around 30 kilometres from high altitude release. This suggests a lift:drag ratio of 3.3:1, which appears reasonable in view of its small aerofoil surfaces.
Development of the rocket-powered Boeing AGM-130 began in 1984, the AGM-130A having the Mk 84 warhead, and the AGM-130C the BLU-109/B penetrator. The operator can set the altitude-hold system to give cruise heights between 1000 and 2000 feet, reducing in the terminal phase to as low as 200 feet. It has a range of 28 kilometres from low-level release, and up to 74 kilometres from high altitude. During the 1991 Gulf War the US Air Force fired 71 AGM-130s from F-15Es and F-111Fs. At the start of Operation Allied Force in Kosovo, US stocks had reduced to around 200, of which half were fired from F-15Es during that conflict. However, 400 more were subsequently ordered. It should be noted that, with launch weights of 1140 and 1323 kg respectively, both the GBU-15 and AGM-130 require a large platform such as the F-4 or F-15.
The US Air Force's other principal missile in this category is the much lighter Raytheon AGM-65 Maverick. Deliveries began in 1972 and it has been used by 30 armed services, including the US Navy and US Marine Corps. More than 66,000 have been built. The Maverick has been produced with three types of guidance: television lock-on for the AGM-65A/B/H, imaging infrared for the AGM-65D/F/G, and laser spot-homing for the AGM-65E. There are two warhead options: the 57-kg shaped charge for the AGM-65A/B/D/H, and the 136-kg penetration/blast warhead for the AGM-65E/F/G/H/K (see below).
With a launch weight of only 210 to 307 kg (depending on the warhead and guidance system), the AGM-65 can be fitted to a very broad spectrum of aircraft. Maximum range is 10 to 14 kilometres from a hovering helicopter, increasing to 24 kilometres from a high level release.
The Maverick airframe is no longer manufactured, but US Air Force AGM-65Gs are being fitted with charge-coupled device seekers to produce AGM-65Ks with improved dusk/dawn capability, while their old imaging infrared seekers are now fitted to stored AGM-65As for export customers. More than 5300 Mavericks were fired in the course of Desert Storm, with a 93 per cent success rate. As a result of experience in Kosovo, where Britain lacked an air-to-ground missile suitable for attacks under low cloud, the Royal Air Force is buying the AGM-65G2 with special anti-armour software.
For longer ranges, the US Navy's next step beyond the AGM-65 is the Boeing AGM-84E Slam (Stand-off Land Attack Missile), which has INS+GPS mid-course navigation and TV guidance in the terminal phase. However, its Teledyne Continental J402 turbojet engine provides a range of more than 100 kilometres, taking it outside the scope of this present discussion. The AGM-84H Slam-ER with variable sweep wings is capable of around 300 kilometres, making it a true cruise missile.
Future US possibilities include the Northrop Grumman Miniature Autonomous Attack Weapon, Long Range, which places the warhead and acoustic sensors from the company's Bat submunition in the airframe of the Miniature Air-Launched Decoy.
Europe's contributions in this field are the MBDA AS.30L and PGM series. The laser spot-homing AS.30L, originally an Aerospatiale product, is a 520 kg supersonic (Mach 1.4) missile with a 240 kg warhead that can penetrate two metres of concrete. It was successfully deployed on French Air Force Jaguars in the 1991 Gulf War, on the service's Mirage 2000Ds in 1995 in Bosnia and most recently in 1999 on French Navy Super Etendards over Kosovo. It has a range in excess of eleven kilometres, and accuracy in the neighbourhood of one metre, which astonished the American forces in the Gulf. The French services have so far ordered more than 900 AS.30Ls.
The MBDA PGM family (originally from GEC Marconi) employs 225- and 900-kg class warheads, with TV, laser or imaging-infrared guidance. The lighter series have a single rocket motor, the heavier versions have two. The PGM has been in production from 1991 and is now in service on the Mirage 2000, F-4, Tornado, Jaguar and Harrier. The lighter version is suitable for operation on aircraft such as the Hawk and F-5. The PGM has a maximum range of 15 kilometres from low-level release, 30 kilometres from medium levels, and up to 50 kilometres from high altitude.
The Kentron Raptor II is a rocket-powered derivative of the battle-proven TV-guided Raptor I glide bomb, with a launch weight of 1200 kg. The Somchem (from the Denel Group) twin rocket motor pod is fixed under the fuselage of the Raptor I and is jettisoned after around 60 kilometres; the missile then glides to a maximum distance of 120 kilometres from release. Terminal accuracy is approximately three metres. The missile, in production since 1998, has been integrated on the Mirage III and F1, the Cheetah and the Su-24 (Fencer).
The Rafael Popeye was developed to provide a stand-off attack capability and as a reaction to Israeli aircraft losses during the 1982 invasion of Lebanon. This rocket-powered missile with inertial mid-course guidance entered service in the late 1980s and was adopted by the US Air Force as a means to give the B-52H a precision strike capability. Lockheed Martin was selected to partner Rafael and the two companies jointly established Precision Guided Systems US in Alabama to produce the Popeye as the AGM-142 Havenap. The AGM-142A, or Popeye 1, carries a 340 kg blast-fragmentation warhead and is fitted with a TV/CCD seeker, providing man-in-the-loop guidance for the terminal phase. It has a launch weight of approximately 1360 kg and a range of around 90 kilometres. The AGM-142C and -142D are reported to have imaging infrared seekers and two different 360 kg-class penetration warheads. The AGM-142E has an improved imaging infrared seeker (sometimes referred to as the Z-seeker) with a selectable field of view.
Following deliveries to Israel and the United States (the US Air Force has had over 200 rounds), the AGM-142 series was exported to Australia, Greece, South Korea and Turkey (110 rounds). For political reasons (it being a semi-Israeli missile), the AGM-142 was not employed during the 1991 Gulf War. Two were fired from a B-52H during Operation Allied Force over Kosovo, but they evidently suffered a software problem.
The AGM-142B Havelite or Popeye 2 is a lightened derivative with a shorter rocket motor and TV guidance. It has a launch weight of 1125 kg to make it suitable for smaller aircraft such as the F-16, but maximum range is unchanged. In 1997 Israel and Turkey reached an agreement to jointly produce the Popeye 2. There were reports that the missile was to be supplied to India, but America is thought to have pressured Israel not to proceed with the sale.
Reputedly inspired by America's Bullpup, Russia's Zvezda-Strela Kh-23 (AS-7) is a 280 kg radio-controlled missile with a nominal range of ten kilometres. This old (1973) weapon was designed for use from the MiG-23 and was exported to more than 30 countries. The Zvezda-Strela Kh-25M (AS-10) is a stretched and slightly heavier derivative, mainly built in the form of the command-guided Kh-25MR and the laser-homing Kh-25ML.
Aside from anti-radiation missiles (of which the Russian Air Force has used many types), the only other Russian tactical air-to-ground missile is the Vympel Kh-29 (AS-14), which appeared somewhat later (1980) and is a much heavier (660 kg) device. The extended-range Kh-29TE version, marketed from 1997, has a range of 17 to 32 kilometres, depending on launch height. The Kh-29 delivers a 320 kg high explosive, penetration warhead, which is designed for attacks on ships of up to 10,000 tonnes, reinforced concrete shelters, runways, large bridges and industrial buildings. It is marketed in three principal forms: the TV-guided Kh-29T series, the laser-spot homing Kh-29L and the infrared-guided Kh-29D.
The class-leader in anti-radiation missiles is the Raytheon AGM-88 Harm (High-speed Anti-Radiation Missile) a 360 kg supersonic weapon that first appeared in 1984 and first saw active service in 1986 over Libya. Approximately 20,000 have been manufactured and 2041 fired in Desert Storm. Maximum range is in excess of 105 km. The missile has been exported to Australia, Germany, Greece, Italy, South Korea, Spain and Turkey. It is planned that the Harm will be replaced by the Advanced Anti-Radiation Guided Missile, based on the AGM-88, with airframe improvements, multi-mode guidance and ultimately a new propulsion system, possibly a ducted rocket.
The 265 kg MBDA Alarm (Air-Launched Anti-Radar Missile) is now in service on British and Saudi Tornadoes. It provides a choice of five operating modes, including one in which it climbs and then loiters under a parachute, scanning for emitters.
Russia has a large array of anti-radiation missiles, starting with the 320 kg Zvezda-Strela Kh-25MP and -25PS (AS-12) variants of the Kh-25 discussed earlier. The company markets the Kh-25MPU (distinguished by a second set of canards) with a range of up to 40 kilometres.
The 715 kg Raduga Kh-28 (AS-9) was the first Russian missile designed from the outset for the anti-radar role. It has a liquid propellant rocket and a range of up to 85 kilometres. Exported to thirteen countries, the supersonic 650 kg Raduga Kh-58E (AS-11) has a seeker that covers five radar bands and a range of 90 kilometres from low-level release, or 170 kilometres from high level.
A modernised version with a range of 250 kilometres has been proposed.
Potentially the world's best lightweight anti-radiation missile, the 600 kg Zvezda-Strela Kh-31P (AS-17) employs ramjet propulsion and has a range of up to 100 kilometres. It is also intended for attacks on Awacs aircraft. Russia and China are reportedly collaborating on a further development, designated KR-1 or YJ-91, presumably for use on the Su-27 and F-8IIM.