Geoffrey Lilley: Aeronautical scientist who persuaded US authorities that Concorde met rules on noise

He inspired generations of aerospace engineers and was one of the few who have flown the Gossamer Condor human-powered aircraft, demonstrating an impressive power-to-weight ratio.

Geoffrey Lilley

Geoffrey Lilley was one of the UK's leading aeronautical scientists. His career encompassed a huge 20th century aviation journey from the Vickers Wellington to Concorde, and latterly to the implications for modern flight of the silent wing flapping of the owl.

In a career spanning 75 years, his finest moment was leading the Concorde team negotiating with the Port Authority of New York, persuading them that the revolutionary supersonic aircraft met strict US noise requirements. If he had failed the aircraft would have been scrapped.

Geoffrey Michael Lilley – GML to friends and colleagues – was born in Isleworth in 1919. His father, Micholl Morland Dessau, was an American inventor who made and lost a great deal of money; he lived at Langham Place in London before his property was demolished to make way for Broadcasting House. His fortune crashed during the Depression and he left the family when Geoffrey, the youngest of four, was 12.

In 1935 Geoffrey left Isleworth Grammar School to join the RAF as an apprentice at Halton. His ambitions to fly were thwarted by short sight and he left the service to pursue a general engineering apprenticeship. After attending a lecture on plans to introduce air conditioning in a London cinema he met a Kodak executive, who offered him a job. Lilley found his feet with Kodak, where he designed and installed a sophisticated air conditioning system, enabling the company to store and process the RAF's vast requirement for high-quality reconnaissance film during the war.

Lilley next joined Vickers at Weybridge, where he worked for a time with Barnes Wallis, of “Dambusters” fame. Lilley stayed in the aircraft industry throughout the war; at night school he completed a BSc and MSc while time devoting two nights a week to Home Guard service on an anti-aircraft battery.

In 1946 he decided to pursue an academic career, becoming one of the founding academics of the College of Aeronautics at Cranfield, now Cranfield University. With a handful of war surplus aircraft, some seized German wind tunnels and ex-RAF students looking for a place in peacetime aviation, Lilley soon established the College as a centre of excellence.

Much of his early research was aimed at exploring the effects of supersonic speed on air crew, and on buildings, animals and people below the flight path. Supersonic flight then was full of mystery and myth: David Lean's 1952 film Sound Barrier popularised all sorts of misconceptions about high-speed flight.

Lilley realised that while almost all military aircraft then in service could only go supersonic in a dive, the real future for high speed air travel was in level flight. His interest led to his joining the Supersonic Transport Aircraft Committee, resulting in his full involvement in Concorde design and noise suppression work using Cranfield's wind tunnel facilities. Virtually all the noise suppression advances on British civilian jets between 1955 and '72 were based on his work. Many patents were taken out, the proceeds often shared with colleagues and students.

In 1955 his career almost came to an end following a serious car crash in the US which led to loss of memory and temporary epilepsy. Two years' rest brought him back to full vigour.

In 1963 he was appointed Professor of Aeronautics at Southampton University. The department achieved world class status, branching out into many related fields, including ship design, rain-spray control on heavy lorries and Formula 1 car research. He inspired generations of aerospace engineers and was one of the few who have flown the Gossamer Condor human-powered aircraft, demonstrating an impressive power-to-weight ratio.

Lilley was one of the fathers of a new field of research that became known as aeroacoustics. Together with Bob Westley at Cranfield he carried out the first experiments on jet noise that motivated and then provided early confirmation of the theoretical work of Sir James Lighthill. He made a crucial extension to the theory with what is now known as Lilley's equation, showing how propagation of sound can be separated from its sources. He made pioneering studies of the sonic boom, which were published in Nature, and 40 years later he was an active participant in what Lighthill called “the Second Golden Age of Aeroacoustics”, when he was a regular visitor to Nasa working with computer simulations of aerodynamic noise.

But it was Lilley's handling of US objections to Concorde that became his finest hour. It was clear to many that despite Nasa's prestigious space programme, some in the US were jealous of Concorde and the fact that America's SST (supersonic transport) programme had flopped. Lilley headed a small technical team tasked with countering the technical objections line by line. Through strict attention to detail and the careful planning of flight paths and throttling-back points they successfully made Concorde's case.

In 1981 Lilley was made an OBE. In 1983 he retired from Southampton, but it was far from the end of his career. A lifelong patriot who resisted many tempting offers from the US, he nevertheless had a huge network of research contacts eager to employ him including Lockheed, Nasa and numerous foreign universities. He became particularly interested in the possibilities of silent flight, both militarily and on civilian jets. The wing configuration of the owl became a focus of his attention, and his work was taken up by both the US and China. Visitors to his home were often perplexed by the dead owls in his fridge.

Geoffrey Lilley was a colourful character who drove Alfa Romeo cars at frightening speed and loved opera, particularly Wagner. A keen raconteur, he loved telling stories often against himself. In 1948 he married Lesley Marion Wheeler – “Peggy” – the eldest daughter of Cranfield school's headmaster in 1948. A colourful character herself and a great support in his career, Peggy died in 1996.

Geoffrey Michael Lilley, aeronautical scientist: born Isleworth, Middlesex 16 November 1919; OBE 1981; married 1948 Leslie Marion Wheeler (died 1996; two daughters, one son); died 20 September 2015.