AGM-/RGM-/UGM-84 Harpoon

The AGM-/RGM-/UGM-84 Harpoon is a long-range sea-skimming, anti-ship missile that is the most widely used anti-ship missile in the West. The ship-launched version of the Harpoon was originally conceived as an air-to-surface missile to attack surfaced Soviet Echo** class cruise missile submarines. The missile is now deployed in surface ships and submarines, in land-based coastal defense positions, and on aircraft for a broad anti-ship role. All Harpoons in US service have been upgraded to AGM/RGM/UGM-84D (Block 1C) level.

CONFIGURATION: thick cylinder with pointed nose; cruciform rapezoidal wings at mid-body, cruciform in-line swept cropped delta control fins at tail, wings and control surfaces fold for storage, pop-out after launch, engine has nearly flush ventral air intake surface-launch version has short booster section with cruciform fins length All Harpoons through Block 1C have the same missile body; different launch systems will use different body wings and fins, and restraint shoes. Harpoons launched from surface ships, submarines, or coastal defense platforms require a booster that is the same for all applications. Air-launched Harpoons do not require a booster and have pylon-attachment lugs instead of shoes. The Block 1D (AGM/RGM-84F) has a 23.2-in (592 mm) plug for more fuel capacity, relocated wings, and an Missile Guidance Unit (MGU) based on the AGM-84E SLAM . (See separate database entry for the SLAM .)

Like the French Exocet missile, the Harpoon is a "fire and forget" weapon (i.e., Harpoon receives no post-launch target position updates from the launch platform). Target information is developed in different ways depending on the platform. Surface ships use the Harpoon Shipboard Command and Launch Control Set (HSCLCS, pronounced "Sickles"). (The Harpoon Coastal Defense System (HCDS) is similar.) Larger aircraft--P-3, F27 Maritime, B-52G, and Nimrod --are fitted with the "stand-alone" Aircraft Command and Launch Control Set (HACLCS or "Hackles"). Others--S-3 Viking and Australian F-111C "Pig"--have a hybrid system that depends in part on the aircraft's weapons control system.

The F-16 's Harpoon Interface Adapter Kit (HIAK) is a hybrid variant having software changes and a control box fitted in the underwing stores pylon. Still other aircraft--notably the A-6E Intruder and F/A-18 Hornet - have Harpoon control functions fully integrated into their Weapons Control Systems. Full integration is also found on US, British Royal Navy, Australian, and Netherlands Navy submarines. Other non-US submarines are fitted with the Encapsulated Harpoon Command and Launch Control Set (EHCLS or "Eckles").

The CLS processes and plots tactical situation information and is the most complex form of Harpoon control. The AN/SWG-1(V) has been upgraded to the SWG-1A(V) to use the Block 1C tactical features, including search pattern sizing, waypoints, offset search, and selectable terminal maneuver. In the SWG-1A(V), when a target is selected, on-line search pattern sizing automatically selects parameters to maximize the probability of hitting the intended target. Waypoint navigation is used to disguise the missile's origins, counter anti-ship missile defense systems, or time multiple missile arrivals to overwhelm the target. In the Block 1C, a flight path may include up to three way points and changes in course, altitude, the range or time gate during which the active radar is on, and terminal attack mode.

Targeting information is loaded into the 16K digital computer that is part of the MGU. The MGU uses a Northrop or Smiths Industries (formerly Lear-Siegler) strapdown, three-axis Attitude Reference Assembly (ARA) to monitor the missile's relation to its launch platform (rather than in relation to the earth as in inertial guidance). If terrain or non-hostile targets need to be avoided, a high-altitude flyout is preferred. A stealthier approach is to drop down to a pre-search sea-skimming altitude.

When the missile reaches a preselected distance from the target's estimated position, the frequency-agile active radar homing seeker uses the programmed Range and Bearing Launch (RBL) search patterns to find targets in a given area. In the Block 1C, the missile has improved Electronic Counter Countermeasures (ECCM) as part of the missile upgrade. The starting point for a circular search is offset from the target in the direction that offers the best chance of acquiring the intended target. The Bearing Only Launch (BOL) is used when the range to the target is not known or when target bearing or range is imprecisely known. The BOL search pattern is square rather than circular.

Terminal attack modes, which are preselected through the CLS, are low-apogee pop-up or sea- skimming to target, depending on sea state and target size and defenses. The high-explosive blast warhead penetrates superstructure or hull plating and detonates in the ship.

Surface ship-launched Harpoons are loaded into one of three types of reusable launch canisters at the factory or at a weapons station. The lightweight canister is mounted on small surface combatants; together with the supporting structure, this variant is known as the Mk 140. The Mk 141 can be fitted with either the shock- resistant Grade-B or thick-walled canisters. In addition, the Harpoon can be fired from Mk 11 twin-rail and Mk 13 single-rail Surface-to-Air Missile (SAM) launchers, or from four cells (two outer on each end) of the eight-cell Mk 16 Anti- Submarine Rocket (ASROC ) launcher.

Submarine-launched Harpoons are carried in a buoyant capsule that is launched from a standard 21-in (533-mm) torpedo tube. The capsule's fins and elevators steer the missile toward the surface, veering away from the submarine's centerline if the tubes lie along the longitudinal axis. When the capsule's nose breaks the surface, the nose cap is blown off, the capsule tail section falls away, and the missile's booster ignites. From that point, the missile's flight is similar to that of a ship- or coastal-launched Harpoon .

Status:
Initial Operational Capability (IOC) in 1977 in surface ships and submarines, 1979 in P-3C anti- submarine patrol aircraft, 1981 in A-6E attack aircraft. IOC for AGM-/RGM-84D in 1984.

First air-launched tests in 1972. 7,000 Harpoons and SLAMs have been ordered from McDonnell Douglas Missile Systems Co (prime contractor), St. Louis, MO with production continuing. Final US Navy Harpoon procurement in FY1989; however, Pre-Planned Product Improvements (P3I) by the US Navy are intended to keep the missile in service beyond 2015 (it is developing the Harpoon Block II to meet this goal-see variants). Orders from non-US customers continue at approximately 100 missiles per year.

In service in the US Navy and in many other countries.

Builders:
Prime Contractor; McDonnell Douglas (now Boeing,) St. Louis, MO, USA. Subcontractor; Texas Instruments (radar seeker), Lewisville, TX, USA.

Users:
Australia, Canada, Denmark, Egypt, Germany, Great Britain, Greece, Indonesia, Israel, Italy, Japan, Korea, Kuwait, Netherlands, New Zealand, Pakistan, Portugal, Saudi Arabia, Singapore, South Korea, Spain, Taiwan, Thailand, Turkey, USA, Venezuela

Characteristics:

 WEIGHT:
    Model
       AGM-84D
                          1,172 lb. (531.6 kg)
       RGM-84D
          Launcher
             Mk 11/13
                          1,527 lb. (692.6 kg)
             Mk 16
                          1,466 lb. (665.0 kg)
             canister/capsule
                          1,530 lb. (694.0 kg)
       AGM-84F
                          1,390 lb. (630.5 kg)
       RGM-84F
                          1,757 lb. (797.0 kg)

 DIMENSIONS:
    Model
       AGM-84D
                             12 ft  7.5 in (3.898 m)
       RGM-/UGM-84D/coastal
                             15 ft  2.5 in (4.635 m)
       AGM-84F
                             14 ft  7.0 in (4.445 m)
       RGM-84F
                             17 ft  2.0 in (5.232 m)
    Diameter
                             13.5 in (340 mm)
    Wing span
                             3 ft  0   in (0.914 m)
 PROPULSION:
    Booster
                          Aerojet or Thiokol solid-fuel rocket
       Static thrust
                          12,000 lb. (5,444 kg)
    Sustainer
                          Teledyne Continental CAE-J402-CA-400 turbojet
       Static thrust
                          600 lb. (273 kg) st; 100 lb. (45.4 kg)
    Fuel
       Block 1C/1D missiles
                          JP-10
 PERFORMANCE:
    Speed
                         Mach 0.85
    Range
       Model
        AGM-84D
                         75-80 nm (86.3-92.1 mi.; 139-148 km)
        AGM-84F
                         approximately 150 nm (173  mi.; 278 km)
 WARHEAD:
    Weight
                         500 lb. (227 kg)
    Type
                         Conventional high-explosive with some penetration
                         capability
 SENSORS:
                         short-pulse radar
                         Kollsman Frequency-Modulated Continuous Wave altimeter
                         Texas Instruments PR-53/DSQ-28 monopulse frequency-
                         agile, jittered Pulse Repetition Frequency active radar
                         homing seeker switched on at pre-planned point
 FIRE CONTROL:
    Targeting
                         HCLS provides targeting data; no updates once missile
                         is launched.
    Guidance
                         on-board Midcourse Guidance Unit (MGU)-IBM digital
                         computer
                         Smiths Industries three-axis ARA
                         Honeywell AN/APN-194

Varients:

AGM-/RGM-84A
Baseline Block 1 variant with JP-5 fuel, slight lower weights, 60 nm (69 mi.; 111 km) range, pop-up terminal attack mode only.

UGM-84B
Sub-Harpoon funded by Great Britain. All Block 1Bs were upgraded to Block 1C configuration by changing the MGU and refueling the sustainer with JP-10 fuel.

RGM-84C (Block 1B production variant)
IOC in 1982. Funded primarily by Great Britain as part of the submarine-launched Harpoon program. Changed flight profile from a climb- and-dive terminal phase to sea skimming throughout the flight.

AGM-/RGM-/UGM-84D (Block 1C)
AGM-84D air launch variant, RGM-84D surface ship variant, UGM-84D submarine launch variant. Features improved sea-skimming, increased range "in excess of" 67 nm (77 mi.; 124 km)-- adoption of JP-10 fuel. Extended range to figure in characteristics way point navigation, on-line search pattern sizing, improved fuze and ECCM, and improved reliability. IOC in 1984. Many to receive Block 1D guidance and software upgrades in retrofits.

AGM-/RGM-84F (Block 1D)
IOC planned in 1993. 23.2-in (0.59-m) extension added to the sustainer section to carry additional fuel making it roughly 90kg heavier. The wings are moved forward to maintain flying characteristics.

Aerodynamic range is approximately 150 nm (173 miles; 278 km). Much of the increased range capability is used for flying a cloverleaf search pattern that permits the Harpoon to resume searching if the target breaks lock on the first pass. MGU incorporates improved memory board, faster Central Processing Unit (CPU), modified ARA originally developed for the AGM- 84E SLAM .

US $9.8 million contract awarded to McDonnell Douglas in September 1989. First air-launched test flight on 4 September 1991, followed by firings from USS JOUETT (CG 29); all five development test phase launches were described as successful. Will not be deployed in submarines, Mk 13 SAM launcher, or ASROC magazines because the missile is too long. Surface vessel fits will require a new launch canister.

Land-launched coastal defense
Ordered by South Korea (three batteries) and Denmark. Missile identical to current production version; quad canister, launched from buyer- supplied vehicle. Launch site need not be level or pre-surveyed. Crew of three. Uses aircraft spotters for over-the-horizon capability. Dutch system uses Terma C3 system to tie into the Baltic-wide C3 system. The South Korean order came in early 1988. Denmark's order came in March 1991 and was delivered in January 1994.

Harpoon 2000
Proposed as a variant in 1996. Later designated Harpoon Block II, this variant is designed to turn the Block IC Harpoon into a dual-role (anti-ship and land-attack) weapon. It is also expected that this version will be integrated into a vertical launch system.

Accurate long-range guidance for land and ship targets is provided by a combined global positioning/inertial navigation system. It is expected to have a range of around 93 miles.

In an otherwise critical General Accounting Office investigation of four major US air- launched missile programs published in September 1987, the summary concluded that the Harpoon 's "overall workmanship quality was reported as very good."

In May 1988, the US Air Force reported that the maximum number of Harpoons to be carried by B- 52Gs had been reduced from 12 to 8 because of fin damage suffered by missiles on the bomber's after external pylons during test flights.

In October 1988, Britain undertook the first Royal Navy surface ship launching of a Harpoon from the frigate HMS CORNWALL. The Harpoon replaced the French Exocet in the British Type 22 Batch 3 (CORNWALL class ).

Operational Notes:
The first combat use of the Harpoon was by US naval forces against Libyan missile corvettes in the Gulf of Sidra in March 1986 (AGM-84A). In the late evening of 24 March, a SHARARA-class (French Combattante II design) missile craft was attacked and sunk by two AGM-84Cs fired by A-6E Intruders from the USS AMERICA (CV 66). About six hours later, the USS YORKTOWN (CG 48) launched an RGM-84A and an RGM-84C at another SHARARA-class craft; sources differ on whether this craft was lost or only damaged. After sunrise on 25 March, an A-6 from the USS SARATOGA (CV 60) fired a single AGM-84C at a Nanuchka II-type missile corvette; this ship was confirmed to have sunk.

On 18 April 1988 the US Navy frigate BAGLEY (FF 1069) launched one RGM-84D Harpoon missile at the Iranian missile craft JOSHAN as she fired an RGM-84A Harpoon at the US ships. Published reports at the time stated that the JOSHAN's Harpoon was confused by chaff fired from the cruiser WAINWRIGHT (CG 28) and the BAGLEY's SH- 2F LAMPS I helicopter and missed. A May 1989 account by the commander of another Surface Action Group (SAG) stated that the missile passed close aboard the WAINWRIGHT's starboard side and he speculated that "the seeker may not have activated."

According to the commander, the US-launched missile missed the JOSHAN, in large part because damage from four Standard missiles fired by the WAINWRIGHT and the frigate SIMPSON (FFG 56) had reduced the JOSHAN's freeboard and made target recognition difficult.

Later that afternoon, an A-6 fired an AGM-84D Harpoon at the Iranian frigate SAHAND after she engaged US Navy warships in the Strait of Hormuz. She was hit aft by the Harpoon , amidships by an AGM-62 Walleye II glide bomb, and forward by an air-launched AGM-123 Skipper II laser-guided missile. Two more Block 1C Harpoons were launched in a coordinated attack by another A-6 and the guided-missile destroyer JOSEPH STRAUSS (DDG 16); both hit the SAHAND, which sank later that night. Reportedly all four missiles hit their targets.

US Navy ships had very few opportunities for using Harpoons during Operations Desert Shield and Desert Storm (August 1990-March 1991) as most Iraqi naval ships and craft were sunk by air-launched bombs and rockets. In late January, the Saudis reported that one of their missile craft sank an Iraqi ship with a Harpoon as it laid mines in the northern Persian Gulf.