Heavy bomber version of the bouncing bomb, was used to destroy the Mohne and Eder dams by Lancasters from the specially recruited and trained 617 Squadron, often known as the Dambusters, under Wing Commander Guy Gibson. In March and April 1945, as the war in Europe was ending, Lancasters dropped Grand Slams and Tallboys on U-boat pens and railway viaducts across north Germany. At Bielefeld more than of railway viaduct was destroyed by Grand Slams creating an earthquake effect, which shook the foundations. The Boeing B-29 Superfortress was a development of the Fortress, but a larger design with four Wright R-3350 Duplex-Cyclone
Wing commander (rank) differing pre-modifying terms. It was also suggested that RAF lieutenant colonels might be entitled reeves or wing-leaders. However, the rank title wing commander was chosen as wings were typically commanded by RAF lieutenant colonels and the term wing commander had been used in the Royal Naval Air Service. The rank of wing commander has been used continuously since 1 August 1919. In the early years of the RAF, a wing commander commanded a flying wing, typically a group of three or four aircraft squadrons. In current usage a wing commander is more likely to command a wing which is an