The BAe Sea Eagle is a medium weight

sea-skimming Sea skimming is a technique many anti-ship missiles and some fighter or strike aircraft use to avoid radar, infrared detection, and to lower probability of being shot down during their approach to the target. Method Sea-skimming anti-ship miss ...

anti-ship missile An anti-ship missile (AShM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea skimming variety, and many use a combination of inertial guidance and active radar homing. A goo ...

designed and built by

BAe Dynamics British Aerospace Dynamics Limited (BADL or BAe Dynamics) was a division of British Aerospace. History British Aerospace was created in April 1977 by the merger of the British Aircraft Corporation, Hawker Siddeley Aviation, Hawker Siddeley Dy ...

(now

MBDA MBDA is a European multinational developer and manufacturer of missiles.MBDA Inc. US Division Co ...

). It is designed to sink or disable

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

s up to the size of

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

s in the face of jamming and other

countermeasures A countermeasure is a measure or action taken to counter or offset another one. As a general concept, it implies precision and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process. The fi ...

including

decoy A decoy (derived from the Dutch ''de'' ''kooi'', literally "the cage" or possibly ''ende kooi'', " duck cage") is usually a person, device, or event which resembles what an individual or a group might be looking for, but it is only meant to lu ...

s. Its users include the

Royal Air Force The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...

and

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...

, the

Royal Saudi Air Force The Royal Saudi Air Force ( ar, ‎الْقُوَّاتُ الْجَوِّيَّةُ الْمَلَكِيَّةْ ٱلسُّعُوْدِيَّة, Al-Quwwat Al-Jawiyah Al-Malakiyah as-Su’udiyah) (RSAF) is the aviation branch of the Saudi Arabia ...

, and the

Indian Navy The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates si ...

History

Previous systems

The anti-ship version of the

Martel missile The Martel is an Anglo-French missile. The name Martel is a contraction of ''Missile, Anti-Radiation, Television'', referring to the guidance options. There are two variants, the passive radar anti-radiation missile version, AS.37, and the televi ...

entered service with the RAF in October 1972 and the Royal Navy one year later. These missiles were designed around a

television guidance Television guidance (TGM) is a type of missile guidance system using a television camera in the missile or glide bomb that sends its signal back to the launch platform. There, a weapons officer or bomb aimer watches the image on a television screen ...

system using a camera in the nose of the missile that sent its image back to the launch aircraft via a

data link A data link is the means of connecting one location to another for the purpose of transmitting and receiving digital information (data communication). It can also refer to a set of electronics assemblies, consisting of a transmitter and a recei ...

radio system. The weapon officer in the aircraft, normally the

Blackburn Buccaneer The Blackburn Buccaneer is a British carrier-capable attack aircraft designed in the 1950s for the Royal Navy (RN). Designed and initially produced by Blackburn Aircraft at Brough, it was later officially known as the Hawker Siddeley Buccane ...

, used the image to guide the missile via signals sent back to the missile on the same data link. This method of operation had been chosen for its simplicity; in comparison, an

active radar seeker Active radar homing (ARH) is a missile guidance method in which a missile contains a radar transceiver (in contrast to semi-active radar homing, which uses only a receiver) and the electronics necessary for it to find and track its target ...

would be prone to all sorts of countermeasures, including

chaff Chaff (; ) is the dry, scaly protective casing of the seeds of cereal grains or similar fine, dry, scaly plant material (such as scaly parts of flowers or finely chopped straw). Chaff is indigestible by humans, but livestock can eat it. In agri ...

and active jamming systems, and would require some form of navigation system for the approach while the missile was still under the

radar horizon The radar horizon is a critical area of performance for aircraft detection systems that is defined by the distance at which the radar beam rises enough above the Earth's surface to make detection of a target at low level impossible. It is asso ...

. The desire for a ship-launched anti-ship missile led to some consideration of an active seeker for the Martel, under the name Ship Martel (or Active Martel). As the launching ship would be under the radar horizon of the target, a data link or similar solution that required a line-of-sight would not work. Marconi won the contract for the radar seeker, a very simple one-axis (left-right) seeker that they claimed would be much less expensive than the Adac seeker of

Exocet The Exocet () is a French-built anti-ship missile whose various versions can be launched from surface vessels, submarines, helicopters and fixed-wing aircraft. Etymology The missile's name was given by M. Guillot, then the technical director ...

or the RE576 used on the

AS.34 Kormoran The AS.34 Kormoran (cormorant) is a German-produced anti-ship missile. The Kormoran uses an inertial guidance system for the midcourse phase, switching to active radar homing during the terminal attack phase. It carries a 165 kg (363 ...

and

Otomat The Otomat is an anti-ship and coastal defence missile developed by the Italian company Oto Melara jointly with Matra and now made by MBDA. The name comes, for the first versions, from the name of the two builders ("Oto Melara" and "Matra") an ...

. A small rocket booster would be used to launch the missile before starting the original engine. This role was ultimately filled by the Exocet and development ended. The Ship Martel work was later picked up for a submarine-launched anti-ship missile, a project known as CL.137 USGW (Under-Sea Guided Weapon). This consisted of a Sea Martel with modifications to allow it to fit into a normal 21-inch torpedo tube, using folding wings and fins. The Marconi seeker was used, but was not fitted during testing. Instead, a simple autopilot with a

radar altimeter A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it t ...

was used in testing at

Aberporth Aberporth is a seaside village, community and electoral ward in Ceredigion, Wales. The population at the 2001 Census, was 2,485, of whom 49 per cent could speak the Welsh language. At the 2011 Census, the population of the community was 2,374 a ...

. A further adaptation was the Sub Martel, otherwise similar but using the Adac seeker from the

, a sub-launched development of the Exocet itself having been abandoned for cost reasons. Ultimately the USGW contest was won by the

Sub-Harpoon The Harpoon is an all-weather, over-the-horizon, anti-ship missile manufactured by McDonnell Douglas (now Boeing Defense, Space & Security). The AGM-84E Standoff Land Attack Missile (SLAM) and later AGM-84H/K SLAM-ER (Standoff Land Attack ...

in September 1975.

Sea Eagle

These developments all suggested the TV-guided Martel was no longer competitive, and a series of studies during 1973 to 1975 came up with specifications for its replacement. This was known as Air Staff Target (AST) 1226 in the Air Force, and Naval Staff Target (NST) 6451 in the Navy. This called for a missile with greater range than Ship Martel, which required the switch to a jet engine. Hawker Siddeley submitted a design using the Marconi seeker and a more highly modified version of the Martel airframe. This would have the advantage of being able to be fired from any aircraft already able to fire the TV guided Martel. Design of the P3T began in 1976, with full scale development initiated in 1979. Although the resulting design looked like the Martel, almost all components differ, with a longer body, larger wings and totally different internal components. A ship-launched version, the P5T Sea Eagle SL, was proposed in 1981. This added two solid-fuel boosters on either side of the missile body, but was otherwise similar to the P3T. It was designed to be fired from its sealed shipping box. The same box was used for the proposed Lightweight Sea Dart, allowing a ship to carry either or both on the same launcher. One advantage to the SL version over competing designs was that it could be fired at very close targets, while most designs, like Harpoon and Exocet, had a fairly long minimum range. Another advantage was that the same missile could be fired from helicopters, like the original Martel, as the rockets could launch it from the helicopter even at very low altitudes without needing high forward speed to allow the small wings to maintain altitude. Production of the finished production weapon began in 1982, around the same time that the name Sea Eagle was bestowed, with test firings up to 1984 and service introduction the following year. The

RAF The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...

Buccaneer Buccaneers were a kind of privateers or free sailors particular to the Caribbean Sea during the 17th and 18th centuries. First established on northern Hispaniola as early as 1625, their heyday was from the Restoration in 1660 until about 168 ...

was the first aircraft to carry a Sea Eagle in active service. This was followed by the Royal Navy's

Sea Harrier The British Aerospace Sea Harrier is a naval short take-off and vertical landing/ vertical take-off and landing jet fighter, reconnaissance and attack aircraft. It is the second member of the Harrier family developed. It first entered servic ...

, as well as the Tornado GR1B in the RAF (replacing Buccaneers) and Royal Saudi Air Force. The Indian Navy also equipped its Sea Harrier FRS Mk.51 and Jaguar IM with the missile, as well as twenty Sea King Mk.42B helicopters, using a version with two booster rockets either side of the rear fuselage. Indian

Ilyushin Il-38 The Ilyushin Il-38 "Dolphin" ( NATO reporting name: May) is a maritime patrol aircraft and anti-submarine warfare aircraft designed in the Soviet Union. It was a development of the Ilyushin Il-18 turboprop transport. Design and development ...

maritime patrol aircraft were also equipped with the rocket-boosted version of the missile, carried on unusual side-fuselage pylons aft of each wing. It has also been reported that India sought to equip its Tupolev Tu-142 fleet with the missile. The

Chilean Air Force "With full speed to the stars" , colours = Indigo White , colours_label = , march = Alte Kameraden , mascot = , anniversaries = 21 March ...

has trial fitted its A-36M Halcon ( CASA 101 Aviojet) with the missile, but this combination never entered service. Several variants of the

BAE Hawk The BAE Systems Hawk is a British single-engine, jet-powered advanced trainer aircraft. It was first flown at Dunsfold, Surrey, in 1974 as the Hawker Siddeley Hawk, and subsequently produced by its successor companies, British Aerospace and B ...

trainer/light fighter have carried the missile on trials. The Sea Eagle was withdrawn from service with the RAF and Royal Navy by 2000.

Design

Sea Eagle is powered by a licence-built, paraffin-fuelled

Microturbo TRI 60 The Microturbo TRI 60 is a small, expendable turbojet engine developed for use in cruise missiles, target drones, and other small unmanned air vehicles. Variants of this engine produce from 3.5 - 5.3 kN (800 - 1200 lbf) of thrust. The e ...

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, a ...

and cruises at speeds of Mach 0.85 (1,040 km/h, 645 mph) throughout its 110

kilometre The kilometre ( SI symbol: km; or ), spelt kilometer in American English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- being the SI prefix for ). It is now the measurement unit used for ...

(68

mile The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 Engli ...

) plus range. It is capable of being carried at supersonic speeds by its parent aircraft, with launch at speeds of up to Mach 0.9 and a wide range of altitudes. Ejector launch, typically from a Type 119 Mk 5 ERU, with a pylon adapter where needed, is used. Once launched the Sea Eagle is completely autonomous, with the flight and target seeking completely controlled by the on-board

computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These prog ...

system which functions according to programmable options covering a large set of cruise, search and attack options, including a simple, pre-programmed 'point and shoot' mode that allows it to be carried by basic aircraft without radar, using targeting information radioed to the pilot from external sources or even visually located by him, with the missile's short minimum range assisting this. Other modes integrate with more sophisticated weapon systems and sensors and allow Sea Eagle to be programmed during flight by the parent aircraft using targeting data from the aircraft's on board radar sensors or via off-board data-link networks. 'Dog leg' routes can be programmed into the missile's computer to allow a salvo of missiles to arrive from different directions, saturating the target's defences. A twin-gyro attitude reference system, digital flight control computer and autopilot are used to give the missile an over-the-horizon capability. A C-band

allows the missile to fly at very low level, minimising the range at which a ship can detect it. The J-band active radar target seeker can detect targets up to 30 km away, allowing a mid-course update of target position through a 'pop up' manoeuvre if required. The guidance system was developed by GEC-Marconi at

Stanmore Stanmore is part of the London Borough of Harrow in London. It is centred northwest of Charing Cross, lies on the outskirts of the London urban area and includes Stanmore Hill, one of the highest points of London, at high. The district, whi ...

. The main wings are essentially of delta form, arranged in a

cruciform Cruciform is a term for physical manifestations resembling a common cross or Christian cross. The label can be extended to architectural shapes, biology, art, and design. Cruciform architectural plan Christian churches are commonly describe ...

configuration. Smaller tails surfaces of similar shape and configuration provide steering. The engine intake is under the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

- whilst carried by an aircraft this is covered by an

aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

fairing which is blown clear at launch. The missile is fitted with a powerful semi-armour-piercing

warhead A warhead is the forward section of a device that contains the explosive agent or toxic (biological, chemical, or nuclear) material that is delivered by a missile, rocket, torpedo, or bomb. Classification Types of warheads include: * Expl ...

, with a high ratio of charge to total weight, encased in a tough metal alloy casing. Residual turbojet fuel adds to the warhead's destructive effects on impact with the target. Sea Eagle is stored as a 'round of ammunition', with inspection every two years or so, and a life of at least 15 years. When stored the wings and tail surfaces are removed, but the weapon can be kept fully fuelled.

Variants

A variant of the missile, called Sea Eagle SL (also P5T), designed to be launched from boxes mounted on ships was tested. It used the same rocket boosters as applied to the helicopter-launched version, but lost out to the American

Harpoon missile The Harpoon is an all-weather, over-the-horizon, anti-ship missile manufactured by McDonnell Douglas (now Boeing Defense, Space & Security). The AGM-84E Standoff Land Attack Missile (SLAM) and later AGM-84H/K SLAM-ER (Standoff Land Attack ...

in a 1984 competition to arm the Royal Navy's Type 22 Batch 3 and

Type 23 frigate The Type 23 frigate or Duke class is a ship class, class of frigates built for the United Kingdom's Royal Navy. The ships are named after List of dukes in the peerages of the British Isles, British Dukes, thus leading to the class being commonl ...

s. This version was also intended to have been used in shore-based batteries. The only external difference from the air-launched version was the use of launcher shoes for rail mounting in the launch box, as opposed to the air-launched version's ejector lugs. An unbuilt air-launched, land attack version of Sea Eagle, using a similar nose radar and semi-armour-piercing warhead, was known as P4T. A later proposed land attack variant which would have had an imaging

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

or millimetre wave radar seeker-head and a data link to allow the launch platform to update the missile in flight was studied around 1990; this version was dubbed "Golden Eagle" and would have had a penetrator warhead to allow attacks on land-based hardened targets. A proposed update of Sea Eagle in the mid-1990s with a dual-band seeker and improved systems was abandoned on cost grounds.

Specifications

*''Wingspan'' : 1.2 metres (3 feet 11 inches) *''Length'' : 4.14 metres (13 feet 7 inches) *''Body Diameter'' : 0.4 metres (1 foot 4 inches) *''Weight'' : 580 kilograms (1,279 pounds) *''Warhead'' : 230 kilograms (510 pounds) of PBX (semi armour-piercing) *''Speed'' : Mach 0.85 (645 mph) *''Range'' : 110 kilometres (68 miles / 60 nautical miles) plus *''Flight time'' : 400 seconds (6 min 40 seconds)

Operators

; ;;

and

(retired) - 2 or 4 missiles * Tornado GR.1B (retired) - 2 or 4 missiles * Sea Harrier FRS.1/FA.2 (retired) - 2 missiles *

BAe Hawk The BAE Systems Hawk is a British single-engine, jet-powered advanced trainer aircraft. It was first flown at Dunsfold, Surrey, in 1974 as the Hawker Siddeley Hawk, and subsequently produced by its successor companies, British Aerospace and B ...

- 1 missile (Trial only) https://i.pinimg.com/originals/9f/89/a6/9f89a605db356b5cd9c35d11ed320250.jpg ; ;;

Indian Air Force The Indian Air Force (IAF) is the air force, air arm of the Indian Armed Forces. Its complement of personnel and aircraft assets ranks third amongst the air forces of the world. Its primary mission is to secure Indian airspace and to conduct ...

and

* Sea Harrier FRS Mk.51 (retired) - 2 missiles * Sea King Mk.42B - 2 missiles * Jaguar IM - 1 or 2 missiles *

- 2 missiles * Tupolev Tu-142 (retired)- 4? missiles ; ;;

Tornado IDS The Panavia Tornado is a family of twin-engine, variable-sweep wing multirole combat aircraft, jointly developed and manufactured by Italy, the United Kingdom and West Germany. There are three primary Tornado variants: the Tornado IDS (interd ...

(retired?) - 2 or 4 missiles ; *A-36M Halcon ( CASA 101 Aviojet) (trials only) - 2 missiles

Notes

References

;Citations

External links

Testing the Sea Eagle on the Sea Harrier Indian integration of Sea Eagle on large maritime patrol aircraft
{{UKmissiles Cold War anti-ship missiles of the United Kingdom General Electric Company Military equipment introduced in the 1980s