The commander of the RAF Bomber Command was Arthur Harris who had first been a cavalryman in World War I and then became a pilot. When he took over Bomber Command he had 378 planes with poor navigation gear and an accuracy problem. He changed the tactics to area bombing primarily against German cities and industry and built a force eventually capable of launching 1,000 plane raids. The primary aircraft were the Lancaster heavy bomber (7,300 with 156,000 missions), the Halifax heavy bomber (6,177 with 75,530 sorties) and the Mosquito medium bomber (made of wood that flew 28,000 operations and lost only 1293 aircraft). The Halifax was also used as very capable night fighter as it had the speed comparable to enemy fighter aircraft. By the time of the last RAF raid on May 23, 1945 Germany laid in ruins from the British night bombing attacks and the American daylight raids. The RAF lost over 55,000 aircrew during the war.