From working on the Miles Marathon and an early drone for ML Aviation to certifying the Boeing 747, Derek Ruben enjoyed a remarkable and distinguished career as an aeronautical engineer. Inspired as a schoolboy in the 1920s by the sight of airships over London and further encouraged in the 1930s by seeing Alan Cobham’s ‘Flying Circus’. Now 104 years old, Derek recalls starting aeronautical engineering degree in the first few months of the Second World War, and enjoying attending one of the earliest post-war courses at the newly established College of Aeronautics at Cranfield.   His career spanned an extraordinary breadth of experience. Recruited to the aerodynamics department at Miles Aircraft during 1942, amongst other projects, he contributed to the Miles Marathon, groundbreaking Miles M.52 project - which, had it not been cancelled, was poised to become the world’s first supersonic aircraft. He went on to address design challenges in a variety of projects with ML Aviation, including an early British UAV, and worked on the stability of the Beagle B.206. Joining the Aircraft Registration Board in the 1970s, he went onto play a pivotal role certifying the Boeing 747 and Concorde in the UK, including working with certification test pilot D. P.  Davies.   Derek shares stories of the people he met during his studies and throughout his career, a journey that vividly reflects the extraordinary advances in aviation over a single lifetime and the enduring ingenuity of designers and engineers in overcoming new challenges.   Derek Ruben was interviewed by Sir George Cox CRAeS as part of the Royal Aeronautical Society/National Aerospace Library’s oral history project ‘If I only didn’t do it that way…….” Capturing history from the horse’s mouth to inspire today’s aeronautical professionals. The recording was edited by edited by Eur Ing Mike Stanberry FRAeS.   A transcript of the interview recording is available on the National Library's Catalogue