Theme : Aerodynamics – The Great Curve – Costin and Sayer Part One

Britain’s Aerodynamic Pioneers – Frank Costin and Malcolm Sayer profiled.


During the 1930s, rapid advancements in aviation were in no small way fuelled by a growing understanding of the science of aerodynamics. Following the outbreak of hostilities in 1939, with scientific interest supplanted by urgent necessity, the pioneering research into airflow management would now come with an added dimension. The increased application of wind tunnel testing allowed engineers to properly assess the behaviour of aircraft in simulated flight and more accurately determine the most efficient shapes.

But as the British aviation industry rapidly contracted in the immediate post-war era, large numbers of highly skilled aeronautical engineers found themselves not only out of work, but vastly over-qualified for the civilian arena. Many found their way by osmosis into UK motorsport, where marginal gains could be translated into race victories. Amongst such figures, two in particular can be rightly described as pioneers: Frank Costin and Malcolm Sayer.

Malcolm Sayer(72)

Born in Cromer, Norfolk in 1916, Malcolm Sayer attended Loughborough University, attaining a first class honours degree in Automotive Engineering. In 1938, he joined the Bristol Aeroplane Company, spending five years in Filton’s experimental department developing the Blenheim and Beaufighter aircraft.

Sayer left Filton in 1948, accepting an offer to set up an engineering facility at Baghdad University. It was was here he is said to have befriended a German engineer who taught him a unique method of mathematical formulae using datum points plotted numerically to determine optimum three-dimensional curves – a discovery which would alter the course of his career. In 1950, with the academic position having proven to have been something of a mirage, he returned to the UK where he initially attempted to make a living as a landscape artist.

Frank Costin

Frank Costin was attracted to the purity of calculus at a tender age, describing Euclid’s theorem one as “the most beautiful thing I’d seen in my whole life.” Born in Middlesex in 1920, he studied for a BSc at Acton Tech before the War intervened. He enrolled as a fitter at General Aircraft, rapidly rising to the drawing office. Specialising in wing design, he later worked at Airspeed, Supermarine and when the former was taken over by De Havilland, became involved in experimental aerodynamic flight testing – ultimately assuming overall responsibility for this work at their Chester division. By the late 1950s however, the industry was declining and by 1958, Costin was gone.

Meanwhile, with a young family to support, Malcolm Sayer replied to an advertisement from Jaguar in 1950, and a short term contract at their experimental racing department quickly found him immersed in a multitude of road and race car projects and a full-time position reporting to engineering chief, Bill Heynes.

Jaguar’s subsequent racing successes were in no small measure due to Sayer’s aptitude with slide rule and logarithms. Sayer’s aviation knowledge became particularly evident in the D-Type’s body and structure design, with it’s stressed alloy fuselage and vertical tail fin, it was to some extent more aircraft than motor car.

The skilled metalworkers in Jaguar’s competition department came to appreciate Sayer’s unorthodox methodology of plotting body co-ordinates, not least because he was so exact in his measurements. According to Experimental department foreman, Bob Blake, one could put one’s finger or a drawing pin at any point on the skin of a Sayer design and he could provide the dimensions to within a thousandth of an inch.

Malcolm Sayer - (centre, left) Bill Heynes and Bob Knight next to the prototype D-type
Malcolm Sayer – (centre, left) flanked by Bill Heynes and Bob Knight next to the prototype D-Type

Described as essentially an analogue version of modern computer aided design, the deep understanding of pure mathematics required was beyond the scope of most outside of Bletchley Park. Nobody at Browns Lane had seen the like, an insider describing him as “quite the miracle”. Sayer would determine the coordinates, which would then be printed onto paper, board, or aluminium, as required. Once skinned, it would be the shape he wanted.

The miracle was that with a tiny budget, Jaguar were capable of besting vastly better funded operations in what at the time was the World’s most prestigious motor race. What gave them their edge was aerodynamics, and without Sayer, Jaguar’s Le Mans dream would most likely have remained just that.

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©Driven to Write. All rights reserved. This series of articles may not be copied, republished (in full or in part) or used in any form without the written permission of the author.

Sources: Loughborough University/Philip Porter/BBC/Motor Sport Magazine/Independent Newspaper

Images: Jaguarbooksite/Loughborough University/BBC/Jaguar Heritage

Author: Eóin Doyle

Co-Founder. Editor. Content Provider.

6 thoughts on “Theme : Aerodynamics – The Great Curve – Costin and Sayer Part One”

  1. De Havilland would have made a very compelling and evocative name for a motor car brand. It’s much more appealing than, say, Bristol. I could see de Havilland making a car along the lines of a small Porsche saloon crossed with Saab qualities.
    I saw a photo of a Tatraplan 600 which had elements that reminded me of what everyone calls the Morse Jaguar. The main difference was that where Jaguar had a notched back, the Tatra had “filled in” the space between the trailing edge of the roof and the boot.

    1. Some of De Havilland’s ideas did get translated into a car by Frank Costin, the plywood construction of the hugely effective Mosquito spawned the plywood chassised Marcos.

  2. Nice but not the same as a proper de Havilland car.
    The 1953 De Havilland 250 had a 2.5 litre straight six of aluminium construction and a hand rivetted all-aliuminium body. It seated 4 and had a remarkable cD of 0.34 thanks to its fared in lamps, covered rear wheels and fastback shape. Top speed was 110 mph. 1, 800 were sold. The prices matched Ferraris of the same period.
    The 1962 De Havilland 280 saw the use of a steel monococque with aluminium doors, boot and bonnet. The recessed gutters and flush windscreen plus Citroen-style undertray meant a further reduction in drag to 0.32. The engine range increased with an aluminium OHC 4 V4 of 2.0 litres and a V6 of 2.0, 2.5 and 2.8 capacities. Clever pressings meant the weight stayed the same while top speed an acceleration improved. A shooting brake and estate were produced by Thrupp and Maberley and were popular in America and Switzerland.

    The 1975 de Havilland 300 increased in size somewhat, now the same size as a Mercedes W-123. The car now had a proper hatchback, discs all around and body designed by Vignale in co-operation with an Italian university’s engineers. The cD was now .31 which inspired Audi to best it with their Audi 100 a while later. However, among the class of exotic sport saloons it was unique, offering fuel economy unseen in the 3.0 class and performance neither Jaguar, Porsche or Maserati could match. The handling and steering “showed Lancia and Alfa how it’s done,” wrote Ted Varker in Car&Driver in 1976. David Bache left Rover to oversee de Havilland’s interior styling in 1978. Sales were steady at 6,000 units annually. A convertible became available in 1980. Various special racing versions did well in motorsport and rallying, as much due to reliability as handling and economy.
    For 1983 two new models were launched, a 320 and the C50. The latter deployed a host of small refinements to push the cD to 0.29 while retaining the same overall dimensions. The C50 slotted in as a BMW 3-series competitor though at Porsche 911 prices. Sales of both cars totalled 18.00 units.
    More to follow…

  3. The idea is really fruitful of possibilities.
    In 1984 de Havilland bought Aston Martin for its production facilities and closed the brand.
    In 1985 they purchased foundering Bristol. In the same year de Havilland bought the rights to Jensen’s 4×4 technology.
    For 1985 they launched a touring version of the large saloon with an estate body and 4 wheel drive. It became the firm’s biggest seller, winning several design awards.
    1989 saw the launch of a new Bristol using de Havilland’s aerodynamic themes, a smaller engine and a higher top speed. A 4×4 version was available with a supercharged engine.
    The 380 appeared in 1995 with a return to full aluminium construction and saloon, hatch, estate and shooting brake formats. It won COTY that year and sales reached 22,000 units at the expanded factory. The cD was 0.28.
    Presently de Havilland make four cars: the C90, the 400, the Bristol 600 and a large touring vehicle with 4×4 and a five door body aimed at the Cayenne but lighter and with class leading off-road performance. Annual sales are at 45,000 units a year. De Havilland have a design consultancy and their engines are used under licence by Lotus and Jaguar and Volvo.

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