BAe Systems Sea Eagle

The BAe Sea Eagle is a medium weight sea-skimming anti-ship missile designed and built by BAe Dynamics (now MBDA). It is designed to sink or disable ships up to the size of aircraft carriers in the face of jamming and other countermeasures including decoys. Its users include the Royal Air Force and Royal Navy, the Royal Saudi Air Force, and formerly the Indian Navy.

History
Sea Eagle stems from 1973 to 1975 studies to meet Air Staff Target (AST) 1226 and Naval Staff Target (NST) 6451 for a successor to the TV-guided AJ.168 version of the Martel missile. Initially called P3T, the airframe follows the Martel layout, but virtually all components differ, with a longer body, larger wings and totally different internal components. The Marconi (now SELEX Sistemi Integrati) active nose radar of Sea Eagle is derived from a British submarine-launched version of Martel dubbed USGW, development of which was abandoned in the mid-1970s in favour of Sub-Harpoon, and was also intended for Active Martel, which was to be similar to P3T in featuring a jet engine. Design of the P3T began in 1976, with full scale development initiated in 1979. 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 Buccaneer was the first aircraft to carry a Sea Eagle in active service. This was followed by the Royal Navy's Sea Harrier, 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 maritime patrol aircraft are 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 has sought to equip its Tupolev Tu-142 fleet with the missile. The Chilean Air Force has trial fitted its A-36M Halcon (CASA 101 Aviojet) with the missile, but it is unclear if this combination entered service. Several variants of the BAe Hawk trainer/light fighter has carried the missile on trials.

Design
Sea Eagle is powered by a licence-built, paraffin-fuelled Microturbo TRI 60 turbojet and cruises at speeds of Mach 0.85 (1,040 km/h, 645 mph) throughout its 110 kilometre (68 mile) 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 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 radar altimeter 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 main wings are essentially of delta form, arranged in a cruciform configuration. Smaller tails surfaces of similar shape and configuration provide steering. The engine intake is under the fuselage - whilst carried by an aircraft this is covered by an aerodynamic fairing which is blown clear at launch. The missile is fitted with a powerful semi armour piercing warhead, 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 in a 1984 competition to arm the Royal Navy's Type 22 Batch 3 and Type 23 frigates. 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 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.

In the mid-1990s, the Sea Eagle was was updated with a dual-band seeker and improved systems.