V1 Flying Bomb

The Vergeltungswaffe 1 FZG-76 (V1), known as the Flying Bomb, Buzz Bomb or Doodlebug, was the first modern guided missile used in wartime and the first cruise missile. Vergeltungswaffe means "reprisal weapon", and FZG is an abbreviation of Flak Ziel Gerät ("anti-aircraft aiming device"), a misleading name.

Called the Buzz Bomb because of the characteristic buzzing sound of the engine it caused considerable fear in the population of London. People would listen for the sound approaching, but then be relieved when it sounded overhead as that meant the bomb had actually passed them.

Developed in Germany during WW II it was used initially against England, mainly London from "ski-jump" launch sites along the French (Pas-de-Calais) and Dutch coasts until they were over-run. It was superseded by the V2 rocket

It was a simple device, designed by Robert Liisser of the Fieseler company as the Fi 103 and could be constructed in around fifty man-hours of mainly sheet metal. It was powered by an Argus pulse jet engine providing 660lb (300kg) of thrust for a top speed of 390mph and a range of around 150 miles (later the range was extended to 250 miles). It was 26 feet (7.9m) long, 17 ft (5.3m) in span, it weighed 4,800lb (2180kg) and carried a 1870lb (850kg) warhead.

The guidance system was very crude in construction but sophisticated in conception (and had a few flaws in execution). Once clear of the launching pad, an autopilot was engaged. It regulated height and speed together, using a weighted pendulum system to get fore and aft feedback linking these and the device's attitude to control its pitch (damped by a gyromagnetic compass, which it also stabilised). There was a more sophisticated interaction between yaw, roll, and other sensors: a gyromagnetic compass (set by swinging in a hangar before launch) gave feedback to control each of pitch and roll, but it was angled away from the horizontal so that controlling these degrees of freedom interacted (the gyroscope stayed trued up by feedback from the magnetic field, and from the fore and aft pendulum mentioned before). This interaction meant that rudder control was sufficient without any separate banking mechanism. On reaching the target, the desired altitude was reset to be negative; this should have led to a power dive, but the steep descent caused the fuel to run away from the pipes and so the power cut out. As there was a belly fuse as well as a nose fuse, there was still usually an explosion although not always with the device buried deep enough to increase the effect of the blast.

The first test flight of a V1 was in late 1941 or early 1942 at Peenemünde. The first offensive launch was on June 12, 1944. The Allies organised a heavy series of air attacks on the launch sites and also attacked the V1s in flight. Due to defensive measures and guidance errors, only a quarter successfully hit their target.

Once the Allies had captured the launch sites that allowed the V1s to hit England the remaining missile strikes were against the port of Antwerp.

Almost 30,000 V1s were manufactured. about 10,000 were fired at England up to March 29, 1945. Of these, about 7000 were "hits" in the sense that they landed somewhere in England, and a little more than half of those (3876) landed in the Greater London area.

An almost equal number were shot down or intercepted by barrage balloons. When the V1 raids began, the only effective defence was interception by a handful of very high performance fighter aircraft, in particular the Hawker Tempest.

Anti-aircraft gunners found that such small, fast-moving targets were difficult to hit, and most fighter aircraft were too slow to catch a V1 unless they had a useful height advantage. Even when caught, the V1 was difficult to bring down: machine gun bullets had little effect on the sheet steel structure and 20mm cannon shells had a shorter range, which meant that setting the warhead off could all too easily destroy the fighter aircraft as well.

When the attacks began in mid-June 1944 there were less than 30 Tempests in 150 Wing to defend against them, and few other aircraft had the low altitude performance to be effective. Initial attempts to intercept V1s were often unsuccesful, but aiming techniques were rapidly developed. (Including the hair raising but effective method of simply flying so close alongside that the airflow disturbed the buzz bomb's gyros and sent it out of control.)

The Tempest wing was built up to over 100 aircraft by September; Griffin[?]-engined Spitfire XIVs and Mustangs were polished and tuned to make them almost fast enough, and during the short summer nights the Tempests shared defensive duty with Mosquitoes. (There was no need for radar - at night the V1's engine could be seen from 10 miles or more away.)

In daylight, V1 chases were chaotic and often unsuccessful until a special defence zone between London and the coast was declared in which only the fastest fighters were permitted. Between June and mid-August 1944, the handful of Tempests shot down 638 flying bombs. (One Tempest pilot, Joseph Berry, downed fifty-nine V1s, another 44, and Wing Commander Beaumont himself destroyed 31.) Next most successful was the Mosquito (428), Spitfire XIV (303), and Mustang, (232). All other types combined added 158. The still-experimental jet-powered Gloster Meteor, which was rushed half-ready into service to fight the V1s, had ample speed but suffered from jamming cannon and accounted for only 13.

In mid-August 1944, the threat was all but overcome - not by aircraft, but by the sudden arrival of two enormously effective electronic aids for anti-aircraft guns, both developed in the USA by the Rad Lab: radar-based automatic gunlaying, and above all, the proximity fuse. Within weeks, the vast majority of V1s launched were shot down by anti-aircraft guns as they crossed the coast.

• Media Files : V1 engine sound (Wikipedia:Sound help)
• See also : Selbstopfer