The Flying Fortress or B-17 was manufactered by Boeing(a leading manufacter and devolper for aircraft.) It was created for the United States Army Air Corps(USAAC) in the 1930's and mass produced in 1938(and stopped in 1945. The prototype actually crashed during testing, but the USAAC still considered it.It served for bombing raids during WWII during the day time. It is a legend and almost literlly a flying fortress, it was behind many mythic stories of it returning home even with extensive damage. It was a high flying bomber, which could defend its self with MG-42 Heavy Machine guns, and a 50 caliber cannon(which would be on the bottem in a semi circle area, which can be seen in the picture.)
Out of the 1.5 million short(metric tons) tons of bombs dropped on Germany, the B-17 dropped 640,000 tons of the bombs. It was first deployed in 1941 with the Royal Air Force. It saw loss of use after World War Two after but wasn't officially retired until 1968 after the Brazilian Air Force stopped using it.