He was responsible for the aerodynamics of the war's most efficient bomber, the de Havilland Mosquito, which could carry the same bomb load to Berlin as a Boeing Flying Fortress using half the power and a fifth of the crew. The Mosquito was so fast it could make two round trips in a night to the German capital, and outrun Goering's Messerschmitts. Nearly 8,000 were built in 40 versions.
Late in 1939 Clarkson had been sent by Sir Geoffrey de Havilland to Salisbury Hall, a secluded Elizabethan manor near St Albans, as a member of a small design team whose secret task, under their chief designer R.E. Bishop, was to realise de Havilland's revolutionary idea for a very fast, light, unarmed bomber.
Before the war Clarkson had worked on the advanced DH88 racer and the streamlined Albatross and Flamingo airliners, pursuing what his boss and mentor Charles Walker called "economic efficiency through aerodynamic purity". He now applied this philosophy to a war machine. The result was the Mosquito.
After the war Clarkson was responsible for the aerodynamics and performance of the Comet, the world's first jet airliner. Though marred in its early years by structural failures, the Comet's aerodynamics and jet power made history by doubling the cruising speeds and altitudes of contemporary airliners.
Clarkson and his team, nearly all in their twenties, had to solve airworthiness problems quite new in commercial air transport - sonic compressibility, shock wave drag, jet intakes handling tons of air a minute, fully powered flying controls without manual reversion, and speed brakes. All these are commonplace in the 11,000 jetliners flying today, but the Comet was first.
The Comet 4, still the sleekest of jetliners, gave 20 years of safe passenger service and made history by winning the race with Boeing to operate the first transatlantic jet service (4 October 1958).
The prototype Mosquito, W4050, flew in November 1940, within a year of the first weight and drag estimates (W4050 has miraculously survived and may still be seen at Salisbury Hall). Clarkson had calculated that the Mosquito would attain 376mph. It actually achieved 388mph - faster than the Spitfire.
In his privately circulated Recollections (1990) Clarkson recalled the Ministry's scepticism: "It cannot be faster than the Spitfire." W4050 was summoned to Boscombe Down, the government aircraft experimental establishment, for a check by the test pilot Allen Wheeler. Fred Rowarth, Boscombe's chief technical officer, analysed the results. "We waited anxiously outside his office door," recalled Clarkson. "Finally he emerged and raised his hat, saying, `I take off my hat to 387mph.' " At the party afterwards in the George Hotel, Amesbury, a merry streak was performed by the test pilot Geoffrey de Havilland Jnr.
Other famous de Havilland aircraft benefited from Clarkson's responsibility for the aerodynamics, performance, stability, aero-elasticity and flight-testing. These included the DH100 Vampire, the world's first mass-produced single-jet fighter (over 4,000 built); the world's fastest piston fighter, the 465mph DH103 Hornet, renowned for its good looks and handling; and the swept wing tailless DH108, the first European jet to exceed the speed of sound (6 September 1948).
Clarkson was also responsible for the aerodynamics of the world's fastest jetliner, the 600mph DH121 Trident. Boeing made an almost identical aerodynamic copy, the 727. The Trident was the world's first airliner to land itself automatically in thick fog carrying fare-paying passengers. That remarkable British achievement (of November 1966) pioneered "systems integration", the marriage of aerodynamics with electronics, commonplace today. Clarkson was a pioneer of computer-aided design, also now routine, with the 1955 Ferranti Pegasus system.
Trident experience helped Clarkson's team to design the wing of Europe's Airbus. The British government had pulled out of the European air consortium, angering the French and Germans and leaving the British on a politically very sloped playing field. Clarkson's team won the wing competition on technical merit with "supercritical" aerofoil sections combining unequalled efficiency in high subsonic cruise with good low speed lift. The French technical director of Airbus, Bernard Ziegler, called it "our beautiful English wing". British Aerospace has made 1,500 of them to date, its most profitable civil business. Recently BAe won the competition to design the wing of the Airbus FLA military airlifter.
Clarkson also influenced the design of 125/Hawker corporate jet, for which he won a Royal Society gold medal, and also the 146/Avro regional jet. BAe's Chester factory has built 900 125/Hawkers, a British civil jet record, and has recently won a Raytheon contract to build 125/Hawker airframes into the next century. Customers include the Japanese Air Force. The 70-100 seat BAe146/Avro also has the "Clarkson touch", achieving brisk runway performance without slats or thrust reversers.
Nimrod, the RAF's maritime reconnaissance aircraft, owes its existence to Clarkson. He had proposed a Comet 4 variant to replace the venerable Shackleton, but head office (then Hawker Siddeley) preferred a Trident development. When the Ministry turned this down as too costly, and threatened to buy the French Atlantique, Clarkson got a phone call from head office: "Put your Comet MR study on a car to St James's Square at once."
The RAF ordered it and has operated Nimrods for nearly 30 years. Recently the MoD ordered British Aerospace to build 25 more, updated as Nimrod 2000s. Clarkson's Comet planform will fly for perhaps another 50 years.
Born in 1904, Richard Clarkson was educated at Clayesmore School (whose choir sung at the Sherborne Abbey memorial service). He took his BSc and ACGI at City and Guilds, which made him one of its rare Fellows.
He was apprenticed to the de Havilland Aircraft Company at Stag Lane, Edgware, in 1925, and gained his pilot's licence in the heroic era of the de Havilland Moths. He met the pioneer pilots and flew the company Hornet Moth on business. He also flew as flight test observer in many new DH aircraft including the DH65 Hound, in which he found himself at 24,000ft without oxygen standing up in an open cockpit trying to read the pilot's instruments.
Clarkson became a remarkable selector and leader of technical staff. Last May, in a video about the birth of jet transport commissioned by the Seattle Museum of Flight, he said of his staff: "They were all brilliant. It is entirely thanks to them that we are in Airbus." Though he could be a hard taskmaster, his staff revered him and kept in touch, visiting him and his wife in their Dorset mill house where he spent nearly 30 years of happy retirement. To celebrate his 90th birthday they arranged a DH90 flypast.
When last year's gales lifted his garden bench and flung it upside down on the lawn, he was typically curious to discover what freak force could pluck such a heavy object from against a wall and throw it into wind. He showed his visitors his graphs and tables of wind velocities, vortex pressures and stagnation points proving that even a garden bench can fly.
Showing an old colleague round his garden earlier this summer, Clarkson demonstrated his renowned love of Shakespeare. The visitor had commented that his rooks sounded like a scene from Macbeth. Clarkson declaimed in the rasping voice well known to erring staff: "Light thickens, and the crow makes wing to the rooky wood". He would invoke Shakespeare often. Hearing of a manage- ment reshuffle, he intoned: "Thus is the eagle mewed, while kites and buzzards prey at liberty.".
Clarkson loved Wagner, above all Parsifal. After a cataract operation last April he signed his letters Wotan. Like his technical reports, his letters were in immaculate English. He used the backs of wastepaper despatched in old envelopes sealed with "Preserve the Rain Forests" or "Don't Let Europe Rule" stickers. He engaged in hunting, ballooning and the Campaign for an Independent Britain.
He was indefatigable in helping the anti-slavery campaigner Margaret Cave to achieve proper recognition for his ancestor Thomas Clarkson (1760-1846). His last engagement was on 26 September when, though unwell, he attended the dedication in Westminster Abbey of a memorial to Clarkson, "the friend of slaves". As senior living descendant he posed for photographs with the present Lord Wilberforce. Three years ago he opened the Clarkson anti- slavery museum in Wisbech, Cambridgeshire.
Richard Clarkson was a Fellow of the Royal Aeronautical Society, which awarded him its British Gold Medal in 1966 for "outstanding contributions to aircraft design".
Richard Milroy Clarkson, aeronautical engineer: born London 14 July 1904; OBE 1950; married 1940 Sylvia Paice (one daughter); died Yeovil, Somerset 7 October 1996.