German scientists began experimenting with guided bombs before the outbreak of the Second World War. The Fritz-X bomb was used for the first time in September 1943. The 1400kg armour-piercing bomb had small wings and a tail unit containing the guidance mechanism. It was controlled during its drop by an observer in the aircraft passing commands via a radio link. It had a range of eight miles and was so fast that anti-aircraft guns found it impossible to hit them. As well as sinking the battleship Roma it also badly damaged the British warship Warspite in 1943.