On June 15, 1936, the Vickers Wellington twin engine bomber made its maiden flight. The bomber would be produced from 1936 until the end of World War II in 1945, with a massive production run of well over 11,400 copies, over 4 000 more than the larger and more famous 7377 Avro Lancasters built. The Wellington was quickly found to be inadequate for a role as a daylight heavy bomber but proved highly effective in other roles as a medium bomber, both versatile and resilient.