Most people who know anything about the RAF in the Second World War say that "Roy Chadwick's role is greatly under-rated". He's not the household name that Barnes Wallis or Guy Gibson became, yet his contribution to the war effort in general was immense.
There is little doubt that the Dambusters raid of May 16/17 could not have happened without the aircraft he designed and the special modifications to it that he personally oversaw.
Chadwick was chief designer at Avro, the aircraft manufacturing company. The Lancaster was his attempt to improve on the Manchester bomber, which had suffered from reliability problems.
Instead of using two Rolls Royce Vulture engines, the new plane used four Rolls Royce Merlin engines. It was a mid-wing cantilever monoplane with an oval all-metal fuselage. Right from its very first operational flights in 1942 it met with the almost unanimous approval of pilots.
Jim McIntosh, a Canadian pilot in 403 Squadron, said that it was "the perfect flying machine. All the controls were within easy reach and designed for use. It was something else. It didn't fly: it soared!"
Yet the standard Lancaster wasn't capable of delivering the Upkeep weapon to the targets without significant modification and, in his determination to get the project approved by Bomber Command, Barnes Wallis, the inventor of the bouncing bomb (Upkeep), had almost certainly under-played the extent of the modifications required.
Chadwick set about his work, designing a special device that held the bomb and allowed it to be rotated, giving it the backspin that was essential for the idea to work.
While other people may not have given Chadwick all the praise he is due, Wallis was well aware of his contribution, writing to him soon after the raid:
"I offer you my very deep thanks for the existence of your wonderful Lancaster, for it was the only aircraft in the world capable of doing the job, and I should like to pay my tribute of congratulation to you, the designer."
This blog is dedicated to the memory of Sergeant Charles Brennan, a flight engineer with 617 Squadron on the Dambusters raid, who was killed in action.