Bringing this over from the T31 News thread re: HMS Gloucester and Silkworm
Ron5 wrote:the RN fired after the missile had missed its target
It is only an assumption (and, to be fair, not an unreasonable one) that Missouri was the target. However, the Missouri's Phalanxes did not activate, implying that the incoming missiles were not heading for Missouri, whereas the Gloucester's did, though did not engage as the missile did not get close enough, being shot down at around 4 nm. It's also worth considering that the seeker on the Silkworm (some accounts say it was a Seersucker, which is a much more capable missile) doesn't activate until the missile is about 4km from the expected position of the target. The missile was around 7nm from Missouri when intercepted, having flown past it's stern (it also flew straight over HMS Cattistock on it's approach, so there is a possiblity that the seeker was defective)
The Iraqi's were in a "use it or lose it" situation, with the Silkworm launch site in danger of being overrun by ground forces advancing from the South and it's quite likely that they would have been happy with any result. Lt-Cmdr Riley, the AAW Officer on Gloucester (and the man who called "Vampire" on the track) thought that Gloucester was the target and that "he had 60 seconds to live" to quote his own words. He spotted the Silkworm on the 992 radar as soon as it flew out of the shore clutter and, on the second sweep (so within 5 seconds), decided it was a missile.
Since a USN A6 and Silkworm look identical on radar, it could have been either a Silkworm or an A6 late in turning its IFF back on (which happened frequently - A6s were also overflying the Silkworm launch site on their return runs, so Riley couldn't discount the track based purely on location). The only deciding factor available to him was the altitude of the track. Silkworms fly at 1000ft (less for a Seersucker) and A6's at 2000ft plus (usually 3000ft), so he had to turn on the 909 radar to ascertain altitude, which took around 30 seconds (a few seconds were also lost as the track number changed while it was being typed in, so it had to be re-entered) and established that it was flying below 1000 ft. Based on that, and his instictive feeling that it was a missile, he fired the Gloucester's missiles at 44 seconds into the engagement.
It's often been said that it was an "over the shoulder" shot, implying that the missile had gone past the Gloucester when she made the shot. The reality is somewhat different. At the point that the launch was detected, both Gloucester and Jarret were coming about, and heading East (the turn direction was mandated by the need to stay within the swept channel), away from the Kuwaiti coast. Gloucester made a hard turn to bring the launchers on the bow to bear, but was only part way through the turn when she fired - that's what made it an "over the shoulder" launch. The Silkworm was still heading towards Gloucester when it was shot down.
It took another four hours to ascertain that they hadn't actually shot down an A6.
As for why Riley "knew" within 5 seconds that it was a Silkworm, he couldn't explain how he "knew" that. There were a number of potential factors - he was aware that the Iraqi missile site was close to being overrun, so he anticipated a last-ditch attempt to mount an attack. He had warned his team only 5 to 10 minutes earlier to expect a Silkworm attack. It was coming from the right direction. It was the only track on the screen at the time, so he was able to focus on it, and perceived that it was accelerating (so could only be a missile). Subsequent analysis actually showed that it wasn't. In the end, analysts realised that the the only visual cue was that, because it was flying lower, the track had appeared further off the coast than an A6 would have. Riley had instinctively realised it, but rationally couldn't figure out why he had done so.
The following day, USS Jarret's Phalanx fired on USS Missouri's chaff cloud (the Iraqi Army dynamiting an oil well was mistaken for the exhaust plume of a Silkworm launch), resulting in Missouri taking slight damage and one minor injury.
The pessimist sees difficulty in every opportunity. The optimist sees the opportunity in every difficulty.