The Royal Navy enjoyed some success in engaging the bombers which launched and guided Hs 293s using anti-aircraft guns. It promulgated a tactic in which a ship should turn as soon as the run-up to launch began to keep the launch bomber as far forward as ‘A’ arcs permitted. As the gliders approached, a ship should alter course to keep them ahead in the hope of making evasive turns. Presenting bow or stern would reduce the chance of a hit to a quarter of that expected by a ship presenting a beam aspect. Since the bomber relied on a continuous view of the target in order to guide the missile, smoke might successfully shield a convoy. Similarly, in the case of FX, long-range anti-aircraft fire could attempt to destroy the parent aircraft both before and after it dropped the bomb. Any evasive action should be toward the direction of attack, as it was easier for the bomb aimer to increase than to decrease the range of the bomb.
The Germans sometimes combined guided weapon attacks with more conventional ones: ships experienced synchronised attacks by Fw 190 fighter-bombers at low altitude while a Do 217 dropped FX from high level. They also tried a combination of Hs 293 and torpedo bombers against convoys.
Although in theory the best counter to missile attack was to use defending fighters to destroy the carrier aircraft, effort was concentrated on electronic countermeasures: receivers to detect the command signal and jammers to disrupt it. Jamming worked even though the antenna on the missile looked up or back at the guiding aircraft, rather than towards the jamming ship. For the longer term, both the Royal Navy and the US Navy began work on guided anti-aircraft missiles (in the US case, the Kamikaze threat spurred action). Both navies were uncomfortably aware that the Germans were operating at stand-off ranges at the outer limit of gun effectiveness (the maximum for a gun was probably 10,000 yds). The Soviets were sufficiently impressed to produce versions of both German weapons after the war.
Hs 293 was the first successful anti-ship guided missile. It may eventually have been defeated mainly by jamming. That it proved so difficult to shoot down inspired initial British and US naval air defence missile projects. After the war, the prospect of faster air-to-surface missiles doomed attempts to develop a new generation of close-range guns, as analysis showed that they were unlikely to be effective. The Royal Navy concluded that ships needed a short-range defensive anti-missile missile, which they called Popsy. This concept, which the Royal Navy was unable to fund, seems to have inspired US work on Tartar, the forerunner of the current Standard Missile. (Dr Raymond Cheung)
The United States mounted an aggressive guided-missile programme roughly in parallel to that of the Germans, but it produced only one operational anti-ship missile, Bat, which entered service in 1945. In contrast to the German missiles, Bat was self-guided using radar (hence the name, since bats home on their targets using echoes, in their case acoustic ones). Bat may have sunk one Japanese ship.37
Kamikazes
The Pacific War counterpart to the German guided bombs was the Japanese Kamikaze, which was guided to its target by a human pilot. En masse they were much more difficult to counter, although each Kamikaze aircraft was an easier target than a small, fast German guided missile. German missiles were used in small numbers, because it took a special aircraft and crew to guide each one. Kamikazes were used in large numbers, because guidance was not a problem. They saturated every level of fleet anti-aircraft control, from fighter direction down to gun fire-control. This experience led to post-war interest in high-capacity combat control systems, ultimately using digital computers.
The Japanese began to consider suicide tactics after the disastrous ‘Turkey Shoot’ of June 1944, when their attack force was nearly annihilated by the fighters launched by Task Force 58. This episode was part of the battle for the Marianas, including Saipan. With the loss of Saipan, many in Japan considered the war lost, or at least that Japan itself was now open to attack. The government which had begun the war, headed by General Hideki Tojo, fell. Suicide attacks (or attacks with virtually no chance of survival) had long had a special place in Japanese thinking, which often emphasised the role of fighting spirit over technology. However, the systematic use of suicide tactics on a large scale, at least in air combat, was a new idea. For the Imperial Japanese Navy, it seems traceable directly to the experience of the battle of the Philippine Sea, the ‘Turkey Shoot’.38
The US Bat was the first successful radar-guided anti-ship missile, guiding itself rather than relying on human commands (the name indicated the guidance technique: the missile homed on radar echoes, as a bat uses sonic echoes). (Norman Friedman)
Kamikazes were first encountered in the Philippines in October 1944. Later intelligence indicated that the tactic had been conceived after the Marianas ‘Turkey Shoot’ of June 1944 destroyed most of the Japanese carrier air arm. The logic was simple: the US Navy had become so efficient that any air attack against a US carrier task force was very nearly suicidal. Kamikazes offered a much better prospect for success. At this time combat air patrol (CAP) fighters were accounting for 60 per cent of attacking aircraft. As Kamikaze attacks continued, less experienced pilots were used, and in any case an aircraft heading directly for a ship was an easier target. By April 1945, 50 per cent of Kamikazes were being shot down without doing damage, compared to 33.6 per cent of conventional attackers – but massed anti-aircraft fire so ruined the aim of conventional attackers that they made only 10 per cent hits, compared to hits by all Kamikazes which survived defensive fire.
On this basis, a force of 300 aircraft would lose 180 to CAP, leaving 120 to attack the fleet. Of those, forty would be shot down by anti-aircraft fire, leaving eighty to attack, of which twelve might do significant damage. It would cost the Japanese 220 aircraft to secure twelve hits.39 To get the same twelve hits would take only sixty Kamikazes. CAP would destroy the same proportion, in this case thirty-six aircraft, leaving twenty-four to attack the ships, of which twelve would be shot down. It would take only a fifth as many sorties to get the same results, and only 27 per cent as many pilots would be killed. To reduce enemy effectiveness to its previous level would be to require the enemy to fly out 220 aircraft (as many as would be lost in the conventional attack) to gain twelve hits. That would require CAP and anti-aircraft fire to destroy 208 aircraft, 95 per cent of the attacking force. A possible division suggested in April 1945 was for CAP to destroy 78 per cent of the attackers (172 aircraft) and AA 75 per cent (thirty-six aircraft). Stating such figures shows how difficult the problem was, once the Japanese were willing to make mass Kamikaze attacks.
The April 1945 figures explain elements of the anti-Kamikaze strategy. Strategic bombing of the Japanese aircraft industry was intended to cut down the supply of new Kamikaze aircraft. Given a limited supply, every attack on Japanese airfields cut the number of available aircraft. Although it was impossible to wipe out the entire supply of such aircraft, at the very least raids on the airfields could neutralise them temporarily. ‘Spikes’ and butterfly bombs could make it temporarily difficult to use airstrips. Most British Pacific Fleet strikes were directed against Japanese airstrips in hopes of limiting the overall Kamikaze threat. By August 1945 US planners contemplating an invasion of Kyushu that November thought that the Kamikaze threat had been considerably reduced in this way, but after the surrender it became clear that very large numbers of aircraft remained hidden, unused even in the urgent defence of Okinawa.
To US analysts, Kamikaze tactics were a natural outgrowth of three earlier types of Japanese tactics, beginning with the second year of the war. In 1943 the Japanese conducted simple, straightforward attacks. Typically they attacked only a few ships, often only one, at one time. Attacking aircraft flew more or less direct courses, and employed only moderate evasive tactics. There were many night attacks. Anti-aircraft fire was generally successful.