NUCLEAR ASMs

Presented by: Dr. Ronnie H. Rusli
Theatrical Defense Policy Analyst


ALCM, AGM-86B

Origin: USA

Type: ALCM

Dimensions: With wings/tailplane extended, length 20·7ft (6·32m); body diameter 24·5ft (6·22mm) span 12ft (3·66m).

Launch weight: 2,825lb (1,282kg).

Propulsion: One Williams F107-101 turbofan with sea-level rating of 600lb (272kg) static thrust.

Range: Max without belly tank, 760 miles (1,200km).

Flight speed: Cruise, about Mach 0.65; terminal phase, possibly Mach 0.8.

Warhead: W-80 thermonuclear as originally developed for SRAM-B.

 

Development: One of the most important weapons in the West’s inventory, ALCM (Air-Launched Cruise Missile) was presented by President Carter as a new idea when he terminated B-1 as a bomber; he even said B-1 had been developed “in absence of the cruise missile factor”, whose presence in 1976 made the bomber unnecessary. This is simply not true. The cruise missile never creased to be studied from 1943, and apart form such USAF examples as Mace and Snark – it was cruise missile studies in 1963-6 that led to AGM-86 SCAD (Subsonic Cruise Armed Decoy) approved by DoD in July 1970. This was to be a miniature aircraft powered by a Williams WR19 turbofan, launched by a B-52 when some hundreds of miles short of major targets.

       Like Quail, SCAD was to confuse and dilute hostile defense; but the fact that some or all would carry nuclear warheads – by 1963 small enough to fit such vehicles – meant that SCAD could do far better than Quail. No longer could the enemy ignore decoys and wait and see which were the bombers. Every SCAD had to be engaged, thus revealing the locations and operating frequencies of the defence sites, which could be hit by surviving SCADSs, SRAM or ARMs. SCAD was to be installationally interchangeable with SRAM, with a maximum range of around 750 miles (1,207km).

       SCAD ran into tough Congresional opposition, but the USAF knew what it was about and in 1972 recast the project as ALCM, retaining the designation AGM-86A. SCAD had had only a secondary attack function, but ALCM is totally a nuclear delivery vehicle, and like SRAM has the ability to multiply each bomber’s targets and increase defence problems by approaching from any direction along any kind of profile. Compared with SRAM it is much easier to intercept, being larger and much slower, but it has considerably greater range and allows the bomber to stand off at distances of at least 1,000 miles (1,609km).

       The original AGM-86A ALCM was interchangeable with SRAM, so that a B-52G or H could carry eight on the internal rotary launcher plus 12 externally, and an FB-111A four externally plus two internally (though the latter aircraft has never been named as an ALCM carrier). This influenced the shape, though not to the missile’s detriment, and necessitated folding or retracting wings, tail and engine air-inlet duct. Boeing, who won SCAD and carrier across to ALCM without further competition, based ALCM very closely on SCAD but increased the fuel capacity and the sophistication of the guidance, with a Litton inertial platform (finally chosen as the P-1000). And computer (4516C), updated progressively when over hostile territory by McDonnell Douglas Tercom.

       In 1976 the decision was taken to aim at maximum commonality with AGM-109 Tomahawk, but the guidance packages are not identical. The engine in both missiles is the Williams F107 of approximately 600lb (272kg) thrust, but in totally different versions; the ALCM engine is the F107-101, with accessories underneath and different starting system from the Dash-400 of AGM-109. The warhead is W-80, from SRAM-B.

 

 

Above: Test launch of an AGM-86A from a B-52: designed to fit SRAM launchers, this version of the ALCM was replaced by AGM-86B.

 

      

AGM-86A first flew at WSMR on 5 March 1976. Many of the early flights failed – one undershot its target by a mile because its tankage had been underfilled! – but by the sixth shot most objectives had been attained and 1977 was spent chiefly in improving commonality with Navy AGM-109, in preparation for something unforeseen until that year: a fly-off against AGM-109 Tomahawk in 1979 to decide which to buy for the B-52 force. It was commonly said Boeing was told to make AGM-86A short on range to avoid competing with the B-1. In fact no more fuel could be accommodated and still retain compatibility with SRAM launchers, and in 1976 Boeing proposed an underbelly auxiliary fuel tank for missiles carried externally.

       A better answer was to throw away dimensional compatibility with SRAM and develop a considerably stretched missile, called AGM-86B. This has a fuselage more than 30 percent longer, housing fuel for double the range with a given warhead. Other changes include wing sweep reduced to 25°, thermal batteries for on-board electrical power, all welded sealed tankage, improved avionics cooling and 10 year shelf life. President Carter’s decision to cancel the B-1 in June 1977 opened the way for Boeing to promote this longer missile, which could still be carried externally under the wings of a B-52 but would not have fitted into the weapon bays of a B-1.

       Form July 1979 Boeing’s AGM-86B was engaged in a fly-off against GD’s AGM-109. Results were hardly impressive, each missile losing four out of ten in crashes, quite apart from other mission-related failures, but after a long delay the USAF announced choice of Boeing on 25 March 1980. A month later it was announced that the USAF/Navy joint management was dissolved and that the USAF Systems Command would solely manage 19 follow-on test flights in 1980 and subsequent production of 3,418 missiles by 1987. The first two rounds assigned to SAC joined the 416th operational B-52G bombers have been converted to carry up to 12 rounds each, in two tandem triplets, and in 1982 President Reagen increased the buy to 3,780 missiles by 1990 to permit 96 B-52H bombers to be equipped also. From 1986 the internal bomb bays are to be rebuilt by Boeing-Wichita to permit each aircraft to carry a further eight rounds on an internal rotary launcher. Each B-52, after conversion, will-root “strakelet”, visible in satellite pictures, as demanded by SALT II provision. The pre-loaded wing pylons will be carried only in time of emergency.

       The production B-1B will carry the same eight-barrel rotary launcher as the rebuilt B-52, and except for the first few aircraft will also carry a further 14 on eight external racks.

 

 

 

Above: AGM-86Bs, with increased range and improved survivability, are loaded on to a B-52.

 

 

 

ASMP

 

Original: France.

Type: Stand-off nuclear missile.

Propulsion: Integrated rocket/ramjet, probably using SNPE rocket with Statolite smokeless filling and Aérospatiale advances kerosene-fuelled ramjet.

Dimension: Length about 16ft 5in (5m), body diameter about 16·5in (420mm); width across inlet ducts about 32·2in (820mm).

Weight: At launch about 2,000lb (900kg).

Performace: Speed about Mach 4, range variable up to 186 miles (300km).

Warhead: CEA nuclear, 150 kilotonne.

 

Development: It is difficult to know whether to class this weapons as tactical or strategic, and the French are not sure themselves. Though it has a fair range, for the initials signify Air/Sol Moyenne Portée, it will have a nuclear warhead. ASMP was initiated in 1971 to arm whatever emerged as the next-generation air craft, successively the Mirage G, ACF (Avion de Combat Futur) and Super Mirage.

       Cancellation of the latter in 1976 reduced the pace of development was initially competitive between Matra with turbojet propulsion, and Aérospatiale with a ram-rocket or ramjet. In March 1978 the 90-ahead was given to Aérospatiale, with liquid-fuel ramjet propulsion. Today an integrated hybrid system has been chosen; France has only limited experience with such propulsion, and may licence technology from CSD, Vought, Marquardt, MBB or other company.

       Range specified for the original (January 1974) ASMP was 50-93 miles (80-150km). This has since been more than doubled, because of the short range of the only available carrier aircraft (Mirage IVA. 2000 and Super Etendard) and the chief puzzle now is how the Antilope 5 radar can acquire targets at over 186 miles (300km). Mid-course guidance is pre-programmed, with Sagem playing a major role in the main inertial guidance. About FF4,000 million is to be spent on 100 missiles, the first of which are now in services with Mirage IVA aircraft of the French Air Force.

 

 

Above: Twin side inlets provide air for ASMP’s ramjet after boost to supersonic speed.

 

 

SS-NX-21/AS-X-15/SS-C-X4

 

Origin: Soviet Union.

Type: SLCM/ALCM/GLCM.

Dimension: Length 22·6ft (6·9m); wingspan 11·3ft (3·44m).

Propulsion: Small turbojet engine.

Weight: Not known

Range: 1,865 miles (3,000km).

Speed: Subsonic.

Warhead: One nuclear.

 

Development: Following the lead given by the USA, the Soviet armed forces have developed a cruise missile capable of being launched from a submarine (SS-NX-21), an aircraft (AS-X-15) or from a ground launcher (SS-C-X4). The sea-based variant is launched from a standard 21in (533mm) torpedo tube and may well equip both the Mike and Sierra class SSNs which are just entering service (qv). SS-NX-21 was expected to enter service in 1984. It can, of course, be deployed in submarines patrolling off the coast of the USA.

       The AS-X-15 was also expected to become operational in 1984 on board the Bear-H ALCM carrier aircraft, a new version of a somewhat elderly machine, as well as the new Black jack bomber, when that reaches IOC. These combinations will give the Soviet air force a real intercontinental capability for the first time.

       Third version is the SS-C-X4 GLCM, which will be deployed on mobile ground launchers, probably similar to those used for the SS-20 IRBM (qv). It is expected to reach IOC in 1985.

       An even newer cruise missile, about double the size of the SS-NX-21, is in a late stage of development and is expected to enter service in 1986-7. Some 43ft (63m) long and with swept wings, this system will have an intercontinental range. Ground and submarine-launched versions have been reported.

 

Below: US DoD artist’s impression of an SS-NX-21 attack profile after firing from a torpedo tube.

 

Continue to Part 2

Back to Index