Beatrice Shilling

Shilling was born at Waterlooville, Hampshire, the daughter of Henry Shilling (1852–1936), a butcher, and his wife Annie (Nancy), née Dulake (1873–1954).

As a child Shilling spent her pocket money on hand tools and won a prize in a national Meccano contest.

At 14 she bought herself a motorcycle, following which she taught herself how to disassemble and reassemble its two-stroke engine; she was already determined to become an engineer.

After completing secondary school she worked for an electrical engineering company for three years, installing wiring and generators.

Beatrice Shilling (8 March 1909 – 18 November 1990) was a British aeronautical engineer, motorcycle racer and sports car racer.

In the 1930s, Shilling raced motorbikes.

After winning a race at the Brooklands racetrack on a motorcycle she modified herself, in a job interview she encountered the sexist comment of "I suppose the men let you win" from the interviewer.

Her employer, Margaret Partridge, encouraged her to study electrical engineering at the Victoria University of Manchester; in 1932, alongside Sheila McGuffie, she received a bachelor's degree and then studied for a further year to get a Master of Science degree in mechanical engineering.

Jobs were hard to find in the Great Depression; she worked as a research assistant for Professor G. F. Mucklow at the University of Birmingham.

On 24 August 1934 she lapped the Brooklands circuit at over 100 miles per hour, with an average speed of 101.85 mph on her Norton M30.

She was only the second woman to achieve this, the first being Florence Blenkiron earlier the same year.

Both were awarded the British Motorcycle Racing Club's Gold Star award.

After the Second World War Beatrice and husband George turned to racing cars, which were tuned and modified extensively in their home workshop - starting off their exploits with a much-lightened 1934 Lagonda Rapier registered KG 5363.

In 1936 she was recruited as a scientific officer by the Royal Aircraft Establishment (RAE), the research and development agency of the Royal Air Force (RAF) in Farnborough, Hampshire.

Her first position was as a technical author with the Air Ministry's technical publications department.

She was allowed to transfer to doing work on aircraft engines.

On 1 November 1939 she was promoted to become technical officer in charge of carburettor research and development and later promoted again to principal technical officer.

Even as a senior member of staff she was respected by the factory workers for her hands-on skills, such as brazing a copper butt-joint with the skills of a dedicated fitter.

Shilling worked on many projects for the Royal Aircraft Establishment (RAE) during the Second World War, the best-known of which was the RAE Restrictor modification (also known as Miss Shilling's Orifice) that solved the problem of Rolls-Royce Merlin engines stalling during negative-g flight.

During the Battle of France and Battle of Britain in 1940, RAF pilots discovered a serious problem in fighter planes with Rolls-Royce Merlin engines, such as the Hurricane and Spitfire.

When the plane went nose-down to begin a dive the resulting negative g-force would flood the engine's SU carburettor, causing the engine to stall.

German fighters used fuel injection engines which avoided this problem.

So in action a German fighter could evade a pursuing RAF fighter by flying a negative g manoeuvre which the RAF plane could not follow.

Shilling devised a restrictor plate to solve this problem.

It was a brass thimble with a hole in the middle (later further simplified to a flat washer), which could be fitted into the engine's carburettor without taking the aircraft out of service.

The restrictor limited maximum fuel flow and prevented flooding.

By March 1941 she had led a small team on a tour of RAF fighter stations (Shilling travelling on her former racing motorbike), installing the devices in their Merlin engines.

The restrictor was immensely popular with pilots and the device was nicknamed Miss Shilling's orifice (an inaccurate nickname, since Shilling was married three years prior and therefore her legal name was "Mrs Naylor") by Sir Stanley Hooker, the engineer who led supercharger development at Rolls-Royce at the time.

It continued in use as a stop-gap until the introduction of the pressure carburettor in 1943.

Shilling also designed the RAE Hobson pressure carburettor, though this was never produced.

After the war, Shilling worked on a variety of projects including the Blue Streak missile and the effect of a wet runway upon braking.

Shilling also helped design and build a bobsled for the Royal Air Force Olympic team.

In 1949, Shilling was made an Officer of the Order of the British Empire.

During the Second World War Shilling designed the RAE Restrictor (which became known as Miss Shilling's orifice), a simple device that overcame the problem of the Rolls-Royce Merlin aeroplane engines losing power during negative-g manoeuvres.

After the war, Shilling also worked on the Blue Streak missile, researched the effect of a wet runway upon braking, and helped design and build a bobsled for the Royal Air Force's Olympic team.

As a motorcycle racer Shilling was one of only three women to receive the British Motorcycle Racing Club Gold Star for lapping the Brooklands circuit at over 100 mph on a motorcycle.

In sports car racing, she scored several podium finishes at the Goodwood Circuit Members' Meetings.

Despite becoming an Officer of the Order of the British Empire in 1949, Shilling never reached a top post in the RAE, since such promotions were only offered to men.

Between 1959 and 1962 they raced an Austin-Healey Sebring Sprite 888 HPA, most frequently at Goodwood Members' Meetings, scoring a number of third places and even one race win.

Shilling worked for the RAE until her retirement in 1969, working as an engineer in the Mechanical Engineering Department.