AGM-45 Shrike | Specs
AGM-78 Standard Arm | Specs
Rockeye II Cluster Bomb
Research and Sources
The first successful anti-radiation (anti-radar) missile and the first one mass-produced the Shrike was developed from 1958 at the Navy Ordnance Test Station (NOTS) at China Lake, California. This is the same organization that created the hugely successful AIM-9 air-to-air missile and the AGM-45 Shrike embodied the same design principles of simplicity and reliabiilty. A total of more than 20,000 Shrikes were produced starting in 1962. The missile saw production in ten blocks with at least 13 seeker heads, each tuned to a different radar type. The Shrike could seek emissions in what is known as the S-band. This covered the FAN SONG radar, used for tracking with the SA-2 Guideline surface-to-air missile, and FIRE CAN, used in gun laying for heavy anti-aircraft artillery. The first AGM-45A Shrike launch from a USAF aircraft (a F-100F Wild Weasel) in Southeast Asia (SEA) happened on 18 April 1966. In 1966, 436 Shrikes were launched in SEA, 1,322 in 1967, and only 523 in 1968.
A typical load-out for a A-4E Skyhawk on a Iron Hand mission would be two Shrikes and two Mk-82 500 lb (227 kg) bombs. When Mk 20 Rockeye II cluster bombs became available in 1968 they were often substituted for the Mk-82s. The Rockeye proved very effective against SAM sites and in flak-suppression against AAA sites. Of course sometimes an Iron Hand A-4 would just carry all (four) Shrikes. Another loadout was two Shrikes and two Bullpup missiles. The AGM-45 could be launched in two different ways. First, in a climb of around 15 degrees three to five miles (5 - 8 km) from a suspected target. This would loft the missile to 20,000 ft (6096 m) where it would descend and home onto a radar emitter within an area about a mile (1.6 km) wide and four miles (6.4 km) long. It could also be used directly against an identified radar emitter in a 45 degree dive at closer range.
Lack of in-built memory meant the missile would go unguided and miss the target if the emitter ceased transmission. However, this action provided a useful result: the attacking aircraft will be in a less threatening environment as the radar is shut down. The missile had a short range well within the SA-2's zone of engagement. This was somewhat rectified with the AGM-45B having an Aerojet Mk 78 solid-propellant rocket giving it more than twice the range of the A model. Overall. there was still considerable room for improvement and this was met with the addition of the AGM-78 Standard anti-radiation missile (ARM).
Info on load-outs and attack profiles from "A-4 Skyhawks VS North Vietnamese AAA" by Peter E. Davies, Osprey publishing (ePub edition), September 2020
Click here to see full specifications of the Shrike and Standard ARM.
Compared to the AGM-45 Shrike the Standard ARM missile was huge with a weight of at least 1,356 lb (615.1 kg) and a length of 15 feet (4.572 m). The new weapon also was more capable than the Shrike, especially the B version and later. Built by General Dynamics the Standard ARM was derived from the Navy's RIM-66 Standard surface-to-air-missile. There were some compatibility issues with the various Standard ARM models. The F-105F Thunderchief configured to launch the A version couldn't make use of the B, C or D versions. When wired to accept the B model and later, the aircraft were designated F-105G but couldn't use the A version of the missile.
The AGM-78B had a gimbaled wide-band seeker covering the S, C, and X-bands to target a range of early warning/ground control intercept and missile guidance radars including BARLOCK, BIGBAR, and those for the SA-2, modified SA-2, and the SA-3 surface-to-air missile systems. This eliminated the need to pre-tune the weapon for a specific threat, opening up targets of opportunity. Frequency coverage of the B and C missiles extended through 2.65 to 3.2 GHz, 4.8 to 5.3 GHz, and 8.8 to 9.6 GHz. The B model of the Standard ARM also introduced a memory circuit to the AGM-78 allowing the missile to stay on course even if the emitter is shut off. All of this came at a cost. The AGM-78 was considerably more expensive than the AGM-45 Shrike. The C model was a AGM-78B made for the USAF. Production ended with the AGM-78D2, the final version of Standard ARM, incorporating even more improvements in the seeker.
Click here to see full specifications of the Shrike and Standard ARM.
The Mk-20 Rockeye II is a sophisticated anti-tank cluster bomb. Development of what would become the Rockeye II began in 1959 at the Naval Ordnance Test Station (NOTS) at China Lake, California. Originally called Hawkeye the tube-shaped dispenser contained 96 submunitions which were modified 2.75-inch (69.9 mm) rocket warheads. This led the developers to rename the weapon Rockeye. Rockeye I was an interm weapon that utilized a backward facing Zuni rocket to blow apart the casing and set the submunitions free. Not only did this prove to be complicated it also proved to be unworkable. Finally came the Rockeye II which contained 247 MK-118 submunitions (bomblets) and an internal aluminum linear shaped charge (ALSC). When activated, it split the thin skinned container length-wise and released the bomblets.
The real difference between Rockeye II and other cluster bombs of the era is found in the fuzing and specifications of the submunition, the MK-118. The MK-118 (Mod 0) was a roughly dart-shaped munition, 13.5 inches (34.3 cm) long and 2.1 inches (5.3 cm) in diameter, weighing 1.32 pounds (599 g). Of this, only .39 pounds (177 grams) made up the warhead, but because it was in the form of a 2-inch (5.1 cm) copper-lined octagonal-shaped charge, it was capable of punching a hole through 7.5 inches (19 cm) of armor plate or 9 inches (22.8 cm) of cold-rolled steel. It featured molten metal moving at 4,000 ft/sec. (1220 m/sec) while doing so.
Although sold as an anti-tank cluster bomb, a target-discriminating (hard or soft) fuze developed by the Naval Ordnance Laboratory (NOL) in Maryland allowed each submunition to be effective against almost any target type. If the descending MK-118 hit concrete, steel or other hard surfaces the shaped charge was triggered and, as described above, cuts through the target. If, on the other hand, it struck a softer surface like the ground it would function as a blast and fragmentation device attacking personnel and materiel.
Rockeye II entered pilot production in 1967 and the US Navy and Marine Corps began using Rockeye in Southeast Asia (SEA) the following year. The USAF tested the Rockeye II at Nellis AFB, Nevada, from 15 July to 4 September 1969. The weapon arrived in SEA in October and the 432d Tactical Reconnaissance Wing at Udorn, Thailand was tasked with conducting the combat evaluation. The evaluation took place in two phases, the first between 29 October and 21 November 1969, the second from 11 to 24 December 1969. Bomb Damage Assessment (BDA) was difficult since the entrance holes left by the weapon in hard objects like AAA guns were far too small to be seen in post-strike recon photos. The state of struck anti-aircraft artillery targets had to be surmised. The results were generally good and they recommended Rockeye's wider use. Cluster bombs like the CBU-24 and CBU-49 would leave a circular pattern 800 feet (244 m) in diameter, Rockeye released from the same altitude would produce an elliptical pattern approximately 200 feet (61 m) by 300 feet (91 m). Accuracy in delivery was crucial but if that was achieved the chances of a hard kill with the Rockeye were high. 10,552 Rockeye IIs were expended during April 1972 - January 1973 over NVN by the USAF.
Source: "Second Generation Weaponry in SEA", HQ PACAF Directorate, Tactical Evaluation Project CHECO SEA Report, 10 September 1970
Source on number of Rockeyes used: "To Hanoi and Back The United States Air Force and North Vietnam 1966-1973" by Wayne Thompson, 2000
|Name||AGM-45A Shrike||AGM·78B Standard ARM|
|Manufacturer||Texas Instruments||General Dynamics|
|In Service||1965||1968 1|
|In Combat||by USAF: 18 April 1966 2||?|
|# Used in Combat||1,935 3||395 3|
|Propulsion||Rocketdyne Mk 39 or Aerojet Mk 53 rocket||Aerojet Mk 27 Mod 4 rocket 4|
|Guidance||TI passive radar seeking||Maxson Electronics passive radar seeking|
|Warhead||145 lb (65.8 kg) Frag-HE 5||214.7 lb (97.4 kg) Frag-HE 5|
|Total Weight||390 lb (176.9 kg)||1,356 lb (615.1 kg)|
|Length||10.00 ft (3.048 m)||15.00 ft (4.572 m)|
|Diameter||8.00 in (20.3 cm)||13.5 in (34.3 cm)|
|Span||36.00 in (0.914 m)||43.00 in (1.092 m)|
|Range||about 10 miles (16 km) 6||70+ mi (112.6+ km)|
|Speed||Mach 2||Mach 2.5|
|1||The AGM-78A introduced in 1968|
|2||The AGM-45 Shrike made its combat debut in 1965 with A-4E Skyhawks of VA-23.|
|3||April - October 1972. USAF fired 678 Shrikes and 230 Standard ARMs. US Navy/Marine Corps fired 1,257 Shrikes and 165 Standard ARMs|
|4||dual-thrust solid-propellant rocket|
|5||The Shrike and Standard ARM both have high-explosive/fragmentation warheads|
|6||The B version of the Shrike has an Aerojet Mk 78 solid-propellant rocket giving a range of up to 28.9 mi (46.5km)|
Estimates vary by source, especially range and cost.
Info for missile usage is from "Planting the Seeds of SEAD: The Wild Weasel in Vietnam" by Major William A. Hewitt, Air University, May 1992
Specifications Info from "A Compendium of Armaments and Military Hardware" by Christopher Chant
"Operation Linebacker I 1972 The first high-tech air war" by Marshall L. Michel III, Osprey publishing (ePub edition), 2019
"Rolling Thunder 1965-1968 Vietnam's most controversial air campaign" by Richard P. Hallion, Osprey publishing (ePub edition), 2018
"Linebacker The Untold Story of the Air Raids over North Vietnam" by Karl J. Eschmann, Lume Books (Kindle edition), 2018
"The Long Road to Desert Storm and Beyond" by Major Donald L. Blackwelder, School Of Advanced Airpower Studies, May 1992
"Second Generation Weaponry in SEA", HQ PACAF Directorate, Tactical Evaluation Project CHECO SEA Report, 10 September 1970
"Linebacker Operations September - December 1972", Project CHECO Office of History HQ PACAF 31 December 1978
Southeast Asia War Gallery of National Air Force Museum
Getting Closer: Precision Guided Weapons in the Southeast Asia War (National Air Force Museum)
National Air Force Museum AGM-45 Shrike
National Archives Catalog
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