Panzer I it still performed much useful service against entrenched infantry and other "soft" targets, which were unable to respond even against thin armor, and who were highly vulnerable to machine gun fire. The small, vulnerable light tank, along with its somewhat more powerful successor the Panzer II, would soon be surpassed as a front-line armoured combat vehicle by more powerful German tanks, such as the Panzer III, and later the Panzer IV, Panzer V, and Panzer VI; nevertheless, the Panzer I's contribution to the early victories of Nazi Germany during World War II was significant. Later in that war the turrets
AI Mk. IV radar be flying by. Instead, they had one of the workers bicycle along a nearby cliff carrying a small plate of aluminum sheet. This neatly demonstrated its ability to detect objects very close to the ground. As AIS rapidly developed into the AI Mk. VII, development of the Mk. IV's follow-ons, the Mk. V, and Mk. VI (see below) saw vacillating support. Considerable additional development of AIS was required, with the first production version arriving in February 1942, and subsequently requiring an extended period of installation development and testing. The first kill by a Mk. VII set was on the night