Sea Skua

Elizzar mentioned the Sea Skua missile’s use in the Falklands war in the comments of an earlier post. And it’s one of my favorite little missiles.

Developed in the late 1970s to give Royal Navy helicopters an Anti-Surface Warfare (ASuW) capability against smaller ships such as patrol boats, the Sea Skua had a remarkably fast development time from the first test firings, on the order of about three years, and was fielded and operational in time for the Falklands in 1982.

The helicopter it was designed for, the Westland Sea Lynx, is a fairly small helicopter, so the Sea Skua was designed to be fairly small itself, with an all up round weighing in at around 300 pounds. Each Sea Lynx could carry up to four missiles.

Most anti-ship missiles use either active radar homing (that is, they carry their own radar to search for a target) or infra-red homing, seeking the heat of the target. The Sea Skua, somewhat unusually, uses semi-active radar homing. That is, the launching Sea Lynx shines its radar on the target, and a radar receiver in the missile homes in on the reflected radar energy. This has a significant drawback in that the launching helicopter has to keep its radar locked on the target for the entire time of flight of the missile. But the choice of guidance systems also has some advantages. First, it was likely cheaper and faster to develop. Second, with the decent range of Sea Skua (roughly 15 miles) the launching helicopter is out of range of most small ship defenses, so tracking the target isn’t an unduly risky proposition. Third, semi-active homing means that the launching helicopter can be sure the missile attacks the correct target, and will not be spoofed to attack either a neutral or lower value target. As a contrast, the Argentine Exocet that destroyed the MV Atlantic Conveyor was (probably) targeted as HMS Illustrious, but was spoofed by chaff, and stumbled upon Atlantic Conveyor afterwards.

The Sea Skua has a small warhead, by anti-ship missile standards, just 62 pounds. And given that it strikes above the waterline, it’s highly unlikely for one missile to sink any but the smallest of targets. But the warhead is sufficient to render most small vessels incapable of continuing the fight. That’s called a “mission kill.” For the most part, simply taking a ship out of the fight is sufficient.

In its introduction to combat in the Falklands, Sea Skua was used to damage an Argentinian patrol boat. Its next foray into combat was during Desert Storm, where considerable numbers were expended against the Iraqi navy with good effect, sinking or badly damaging about a dozen ships.

Just as the Westland Lynx has enjoyed considerable export success, so naturally has the Sea Skua. Users beside the Royal Navy include Germany, Brazil, Malaysia, India, Kuwait, Pakistan, and Korea.

[youtube https://www.youtube.com/watch?v=kRQXbSC0IJo]

The Sea Skua can also be installed and launched from small surface ships too small to accommodate other larger anti-ship missiles.

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[youtube https://www.youtube.com/watch?v=iAh8Pv5F-yA]

The US Navy, finding itself in need of a missile system to equip its own SH-60 Seahawk helicopters, opted instead for the Norwegian designed Penguin missile. Unlike Sea Skua, Penguin uses an infra-red seeker. In addition, for even smaller threats, most Seahawks can now carry four or eight Hellfire semi-active laser guided missiles, with a range of about 5 miles. The much smaller Hellfire is quite sufficient for attacking the very small fast boats that would constitute a swarm type attack.

Sea Skua itself, after an admirable career over three decades long, is slated to be replace by a newer missile, Sea Venom, sometime around 2020.