Yes, there were. Germany had some 27 models of aircraft classed as either helicopters or autogyros.
It's when aircraft from one side bombed a city from the other side, such as the Germans bombing London, or the Americans bombing Berlin.
No
1945
yes
he died
world war2
No.
World war2
Japan
That's a very difficult answer to pin on ONE country, as Britain, USA and Germany ALL made significant advances in aviation during WW2.
September 3rd 1939