12 April 1937: At his laboratory at the British Thompson-Houston Works in Rugby, Warwickshire, England, Royal Air Force Flight Lieutenant Frank Whittle prepares the first test of his prototype aircraft engine, the Power Jet W.U. (“Whittle Unit”), which he calls a “supercharger.”

Using an electric motor, Whittle spins the engine up to 1,000 r.p.m. He switches on the pilot jet, which sprays atomized diesel fuel into the engine’s combustion chamber. A hand-cranked magneto supplies electricity to fire a spark plug to ignite the fuel. Whittle continues to spin the engine to 3,000 r.p.m., at which speed the combustion cycle is self-sustaining. The Whittle Unit continues to accelerate uncontrolled to about 8,500 r.p.m.

This was the very first successful test of a turbojet engine.¹

With the exception of the uncontrolled acceleration, the test was successful. It would later be found that the acceleration was caused by liquid fuel pooling in the combustion chamber. The Whittle Unit was based on Whittle’s own patent, No. 347,206, which was filed 16 January 1930. The patent was published in 1931. (Following World War II, copies of these patent documents were found at several laboratories in Germany.) In 1935, Whittle was unable to afford the £5 required to renew his patent, and it entered the public domain.

The Power Jet W.U. was a single-shaft turbojet engine with a single-stage, centrifugal-flow compressor, a single combustion chamber, and a single-stage, axial-flow turbine. The engine had two air intakes, one for each side of the compressor impeller. The impeller was double-sided with a diameter of 19 inches (48.26 centimeters). It had 30 blades and was constructed of Hiduminium R.R. 56, a high strength, high-temperature, aluminum alloy produced by High Duty Alloys, Ltd., at Slough, Berkshire, England. The compressor blade tips had a width of 2 inches (5.08 centimeters). The inner diameter of the compressor scroll was 31 inches (78.74 centimeters). The turbine was 14 inches (35.56 centimeters) in diameter with 66 individual blades. Each blade was 2.4 inches (6.096 centimeters) long, with a chord of 0.8 inches (2.032 centimeters). The turbine was constructed of Firth-Vickers Stayblade, a chrome-nickel stainless steel alloy produced by Firth Brown Steels of Sheffield, South Yorkshire, England. The turbine bearing housing was water-cooled.²

Air entered the compressor where it was heated and pressurized by the spinning impeller to about 4 times normal atmospheric pressure. This caused the air temperature to increase substantially. The pressurized air was passed on to the combustion chamber where the fuel spray was ignited by the spark plug. Burning gas passed through the turbine blades, causing them to spin at very high speeds. The turbine turned a shaft which lead forward to turn the compressor impeller. Exhaust expelled through the tailpipe provides thrust.

Testing of the Whittle Unit continued until 23 August 1937. For reasons of safety, British Thompson-Houston would not allow Whittle to test the engine above 12,000 r.p.m., and recommended that he move his laboratory to a BTH-owned foundry at the Ladywood Works, Lutterworth, Leicestershire, England.

After analyzing test data, Whittle concluded that the Power Jet W.U. had poor compressor efficiency; that there was excessive preheating of air entering the rear intake because of combustion chamber heat; the combustion of the air/fuel mixture was unsatisfactory; and there was excessive frictional loss in the turbine.

The W.U. eventually reached 17,750 r.p.m and produced approximately 1,390 pounds of thrust (6.18 kilonewtons). Whittle continued testing a series of improved W.U. turbojets until 1941, when he built the Whittle W.1X engine.

On 15 May 1941, a Whittle W.1 powered the Gloster E.28/39 prototype jet fighter on its first flight. (In October 1941, General Henry Harley (“Hap”) Arnold, U.S. Army Air Forces, arranged to have the W.1X flown to the United States so that the U.S. could develop its own jet engine, the General Electric Type I.)

* * * * * * *

Air Commodore Sir Frank Whittle, O.M., K.B.E., C.B., F.R.S., F.R.Ae.S., Royal Air Force, was born 1 June 1907 at 72 Newcombe Road, Earlsdon, Coventry, England. He was the older of two sons of Moses Whittle, a foreman in a machine tool factory, and Sara Alice Garlick Whittle. He attended Earlsdon Council School, just around the corner from his home. In 1916, the Whittle family moved to 9 Victoria Street, Royal Leamington Spa, in Warwickshire, where he was educated at the Milverton Primary School. After about two years, he earned a scholarship to what would later be called the Leamington College for Boys.

In 1923, Frank Whittle left school to join the Royal Air Force. He was initially turned down because he was just 5 feet tall (1.52 meters) and very underweight. Six months later, he had grown another 3 inches (7.6 centimeters) and increased his weight and strength. Whittle was accepted under an assumed first name (he soon reverted to his real name) to a three-year course as an aircraft mechanic. A superior officer recommended him for officer and pilot pilot training at the Royal Air Force College, Cranwell, in Lincolnshire.

Frank Whittle graduated from RAF Cranwell and on 21 August 1928 was granted a permanent commission as a Pilot Officer, Royal Air Force, with seniority from 28 July. He was considered to be an exceptional pilot, and had scored second in his class in academics. At his graduation ceremony, Whittle, flying an Armstrong Whitworth Siskin at 1,500 feet (457 meters), performed an aerobatic maneuver called an “English bunt,” the first RAF officer to do so.³

Pilot Officer Whittle served as a pilot and flight instructor, and was promoted to the rank of Flying Officer, 28 January 1930.

Flying Officer Whittle married Miss Dorothy Mary Lee at Coventry, 24 May 1930. Mrs. Whittle was three years his senior. They would have two sons, David and Ian.

In 1931, Whittle was assigned as a test pilot at the Marine Aircraft Experimental Establishment, Felixstowe, Suffolk. He flew more than 20 aircraft types.

In 1932, he attended the Officers School of Engineering at RAF Henlow, in Bedfordshire. Flying Officer Whittle was promoted to the rank of Flight Lieutenant, 1 February 1934. Whittle had scored so high in his studies at Henlow that the RAF sent him to the RAF E Course at the Peterhouse College of the University of Cambridge. He graduated in 1936 with Bachelor of Arts degree and a First in Mechanical Sciences Tripos.

While at Cambridge, Flight Lieutenant Whittle entered into a partnership to form Power Jets Ltd., and began work on his design for the Power Jets W.U. The engine would be built by the British Thompson-Houston Works.

On 1 December 1937, Flight Lieutenant Whittle was promoted to the rank of Squadron Leader. The RAF assigned him to the Special Duty List, allowing him to continue post-graduate work at Cambridge and to work on the turbojet engine.

Squadron Leader Whittle was promoted to Wing Commander (temporary), 1 June 1940.

Wing Commander Whittle developed the Whittle W.2, which powered the Gloster Meteor on its first flight, 5 March 1943. He was promoted to Group Captain (temporary), 1 July 1943.

Group Captain Whittle was appointed Commander of the Military Division of the Most Excellent Order of the British Empire (CBE), 1 January 1944. He was promoted to Acting Air Commodore.

King George V, on 5 November 1946, granted unrestricted permission to Air Commodore Whittle, CBE, to wear the Legion of Merit in the degree of Officer, a military decoration conferred by the President of the United States for exceptionally meritorious conduct in the performance of outstanding services and achievements.

In the King’s New Year’s Honours List, 1 January 1947, Air Commodore Whittle, CBE, was appointed a Companion of the Most Honourable Order of the Bath (CB). In May 1948, for his work on jet engines, Whittle was awarded £100,000 ⁴ by Royal Commission on Awards. King Edward VIII appointed Air Commodore Whittle an Ordinary Knight Commander of the Most Excellent Order of the British Empire (KBE), 10 June 1948.

Group Captain Sir Frank Whittle, KBE, CB, was retired from the Royal Air Force, 26 August 1948, due to medical unfitness for Air Force service. He retained the rank of Air Commodore.

After retiring from the RAF, Whittle joined the British Overseas Airways Corporation as a technical adviser. He left BOAC in 1952. On 1 January 1953, Frederick Mueller Ltd. published his autobiography, Jet: The Story of a Pioneer. Later that year, he joined Shell, one of the world’s largest petroleum companies, as a Mechanical Engineering Specialist. He invented a turbine-powered oil well drill. In 1957, he went to work for Bristol Aero Engines.

In 1960, the Norwegian Institute of Technology, Trondheim, Norway, awarded Whittle an honorary degree, Doctor Technices honoris causa. In 1967, the University of Bath, in Somerset, England, awarded him the honorary degree of Doctor of Science.

From 1967 to 1976, Sir Frank and Lady Dorothy resided at Walland Hill, a 4,130 square foot (383.6 square meters) house on 5 acres, built in 1865, and overlooking the Teign Valley and Dartmoor. The house is situated about ¾-mile (1.2 kilometers) from Chagford, Devon.

Following his divorce from Dorothy, Lady Whittle, Sir Frank Whittle married the former Mrs. Virgil Lee Hall (née Hazel Ardyce Steenberg) on 5 November 1976, at Fort Leslie J. McNair, at a United States Army base located in Washington, D.C. He emigrated to the United States in 1977 and became a research professor at the United States Naval Academy at Annapolis, Maryland.

Whittle was the author of a textbook, Gas Turbine Aero-Thermodynamics With Special Reference to Aircraft Propulsion, published by Pergamon Press, Oxford, in 1981.

On 14 February 1986, Queen Elizabeth II appointed Whittle to the Order of Merit (OM), dated 11 February 1986.

Loughborough University, Leicestershire, awarded Whittle the honorary degree of Doctor of Technology in 1987.

In February 1996, Whittle was diagnosed with lung cancer. 24 days after the death of his first wife, Lady Dorothy, at 10:40 p.m., 8 August 1996,⁵ Air Commodore Sir Frank Whittle, O.M., K.B.E., C.B., F.R.S., F.R.Ae.S., Royal Air Force (Retired), died at his home at 10001 Windstream Drive, #707, Columbia, Maryland. He was 89 years old. His remains were cremated, then interred at St. Michael’s and All Angels’ Church, RAF Cranwell.

A memorial was held at Westminister Abbey, 15 November 1996. Air Chief Marshall Sir Michael James Graydon, GCB, CBE, FRAeS, said of him, “It is given to few people, and even fewer in their own lifetime, to open up new horizons for their fellow human beings. That is what Frank Whittle did by paving the way for popular air travel on a scale that few people thought possible at the time. This practical realization of a soaring vision is surely the very essence of genius.”

The Daily Telegraph called him “the greatest aero engineer of the century.” Prime Minister Margaret Thatcher said, “Sir Frank helped to change both the way we live and the world we live in.”

A very interesting documentary about Whittle, including interviews with the Air Commodore, can be seen on YouTube:

¹ Hans-Joachim Pabst von Ohain’s turbojet engine, the Heinkel HeS 1, burning gaseous hydrogen, was first run in September 1937, about six months after Whittle’s Power Jets W.U.

² “The Whittle Jet Propulsion Gas Turbine,” by Air Commodore Frank Whittle, C.B.E., R.A.F., M.A., Hon. M.I. Mech.E., The Engineer, 12 October 1945, Pages 288–290.

³ The English bunt begins in straight and level flight. The pilot performs an outside half loop, ending in inverted level flight.

⁴ Equivalent to £4,651,934/$5,771,654 in 2023.

⁵ 02:40, 9 August, UTC.

© 2023, Bryan R. Swopes