Frank Whittle

Frank Whittle

Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS (1st June 1907 – 9th August 1996) was an English Royal Air Force (RAF) officer. Sharing credit with Germany's Dr. Hans von Ohain for independently inventing the jet engine, he is hailed as a father of jet propulsion.

From an early age Whittle demonstrated an aptitude for engineering and an interest in flying. Determined to be a pilot, he overcame his physical limitations to be accepted into the RAF where his abilities earned him a place on the officer training course at Cranwell. He excelled in his studies and became an accomplished pilot. While writing his thesis there he formulated the fundamental concepts that led to the creation of the jet engine, taking out a patent on his design in 1930. His performance on an officers' engineering course bought him a place on a further course at the University of Cambridge where he graduated with a First.

Without Air Ministry support, he and two retired RAF servicemen formed Power Jets Ltd to build his engine with assistance from the firm of British Thomson-Houston. Despite limited funding, a prototype was created which first ran in 1937. Official interest was forthcoming following this success with contracts being placed to develop further engines, but the continuing stress seriously affected Whittle's health, eventually resulting in a nervous breakdown in 1940. In 1944 when Power Jets was nationalised he again suffered a nervous breakdown, and resigned from the board in 1946.

In 1948 Whittle retired from the RAF and received a knighthood. He joined BOAC as a technical advisor before working as an engineering specialist in one of Shell Oil's subsidiaries followed by a position with Bristol Aero Engines. After emigrating to the U.S. in 1976 he accepted the position of NAVAIR Research Professor at the United States Naval Academy from 1977–1979. In August 1996, Whittle died of lung cancer at his home in Columbia, Maryland.

Early life

Whittle was born in a terraced house in Newcombe Road, Earlsdon, Coventry, England on 1 June 1907, the eldest son of Moses and Sara Alice Whittle. When he was nine years old, the family moved to the nearby town of Royal Leamington Spa where his father, a highly inventive practical engineer and mechanic, purchased the Leamington Valve and Piston Ring Company which comprised a few lathes and other tools, and a single-cylinder gas engine on which Whittle became an expert. Whittle developed a rebellious and adventurous streak together with an early interest in aviation.

After two years attending Milverton School, Whittle won a scholarship to a secondary school which in due course became Leamington College, but when his father's business faltered there was not enough money to keep him there. He quickly developed practical engineering skills while helping in his father's workshop, and being an enthusiastic reader spent much of his spare time in the Leamington reference library, reading about astronomy, engineering, turbines, and the theory of flight. At the age of 15, determined to be a pilot, Whittle applied to join the RAF.

Entering the RAF

In January 1923, having passed the RAF entrance examination, Whittle reported to RAF Halton as an aircraft apprentice. He lasted only two days: just five feet tall and with a small chest measurement, he failed the medical. He then put himself through a vigorous training program and special diet devised by a physical training instructor at Halton to build up his physique, only to fail again six months later when he was told that he could not be given a second chance, despite having added three inches to his height and chest. Undeterred, he applied again under an assumed name and presented himself as a candidate at the RAF Cranwell apprentice school instead. This time he passed the physical, and in September that year, 364365 Boy Whittle, F started his three-year training as an aircraft mechanic at the No. 4 Apprentices Wing, No. 1 School of Technical Training.

Whittle hated the strict discipline, and convinced there was no hope of ever becoming a pilot, at one time seriously considered deserting. However, throughout his early days as an aircraft apprentice, first at the Royal Air Force College Cranwell, and latterly at RAF Halton, he maintained his interest in the Model Aircraft Society where he built replicas. The quality of these attracted the eye of his commanding officer, who felt that Whittle was also a mathematical genius. He was so impressed that in 1926 he recommended Whittle for officer training at Cranwell, a rarity for a "commoner" in what was still a very class-based military structure.

For Whittle, this was the chance of a lifetime, not only to enter the officer corps but also because the training included flying lessons on the Avro 504. While at Cranwell he lodged in a bungalow at Dorrington. Being an ex-apprentice amongst a majority of ex-public schoolboys, life as an officer cadet wasn't easy for him, but he nevertheless excelled in the courses and went solo in 1927 after only 13.5 hours instruction, quickly progressing to the Bristol Fighter and gaining a reputation for daredevil low flying and aerobatics.

A requirement of the course was that each student had to produce a thesis for graduation: Whittle decided to write his on potential aircraft design developments, notably flight at high altitudes and speeds over 500 mph (800 km/h). In Future Developments in Aircraft Design he showed that incremental improvements in existing propeller engines were unlikely to make such flight routine. Instead he described what is today referred to as a motorjet; a motor using a conventional piston engine to provide compressed air to a combustion chamber whose exhaust was used directly for thrust – essentially an afterburner attached to a propeller engine. The idea was not new and had been talked about for some time in the industry, but Whittle's aim was to demonstrate that at increased altitudes the lower outside air pressure would increase the design's efficiency. For long-range flight, using an Atlantic-crossing mailplane as his example, the engine would spend most of its time at high altitude and thus could outperform a conventional powerplant.

Of the few apprentices accepted, only about one percent normally completed the course, and Whittle graduated in 1928 at the age of 21. He ranked second in his class in academics, won the Andy Fellowes Memorial Prize for Aeronautical Sciences for his thesis, and was described as an "exceptional to above average" pilot. However, his flight logbook also showed numerous red ink warnings about showboating and overconfidence, and because of dangerous flying in an Armstrong Whitworth Siskin he was disqualified from the end of term flying contest.

Development of the jet engine

Whittle continued working on the motorjet principle after his thesis work but eventually abandoned it when further calculations showed it would weigh as much as a conventional engine of the same thrust. Pondering the problem he thought: "Why not substitute a turbine for the piston engine?" Instead of using a piston engine to provide the compressed air for the burner, a turbine could be used to extract some power from the exhaust and drive a similar compressor to those used for superchargers. The remaining exhaust thrust would power the aircraft.

On 27 August 1928 Pilot Officer Whittle joined No. 111 Squadron, Hornchurch, flying Siskin IIIs. Continuing his reputation for low flying and aerobatics, one public complaint almost led to him being court-martialled. Within a year he was posted to Central Flying School, Wittering, for a flying instructor's course. He became a popular and gifted instructor, and was selected as one of the entrants in a competition to select a team to perform the "crazy flying" routine in the 1930 Royal Air Force Air Display at RAF Hendon. He destroyed two aircraft in accidents during rehearsals but remained unscathed on both occasions. After the second incident an enraged Flight Lieutenant Harold W Raeburn said furiously, "Why don't you take all my bloody aeroplanes, make a heap of them in the middle of the aerodrome and set fire to them – it's quicker!"

Whittle showed his engine concept around the base where it attracted the attention of Flying Officer Pat Johnson, formerly a patent examiner. Johnson, in turn, took the concept to the commanding officer of the base. This set into motion a chain of events that almost led to the engine being produced much sooner than actually occurred.

Earlier, in July 1926, A. A. Griffith published a paper on compressors and turbines, which he had been studying at the Royal Aircraft Establishment (RAE). He showed that such designs up to this point had been flying "stalled", and that by giving the compressor blades an aerofoil-shaped cross-section their efficiency could be dramatically improved. The paper went on to describe how the increased efficiency of these sorts of compressors and turbines would allow a jet engine to be produced, although he felt the idea was impractical, and instead suggested using the power as a turboprop. At the time most superchargers used a centrifugal compressor, so there was limited interest in the paper.

Encouraged by his Commanding Officer, in late-1929 Whittle sent his concept to the Air Ministry to see if it would be of any interest to them. With little knowledge of the topic they turned to the only other person who had written on the subject and passed the paper on to Griffith. Griffith appears to have been convinced that Whittle's "simple" design could never achieve the sorts of efficiencies needed for a practical engine. After pointing out an error in one of Whittle's calculations, he went on to comment that the centrifugal design would be too large for aircraft use and that using the jet directly for power would be rather inefficient. The RAF returned comment to Whittle, referring to the design as being "impracticable".

Pat Johnson remained convinced of the validity of the idea, and had Whittle patent the idea in January 1930. Since the RAF was not interested in the concept they did not declare it secret, meaning that Whittle was able to retain the rights to the idea which would have otherwise been their property. Johnson arranged a meeting with British Thomson-Houston (BTH) whose chief turbine engineer seemed to agree with the basic idea. However, BTH did not want to spend the ?60,000 it would cost to develop it and this potential brush with early success went no further.

In Coventry, on 24 May 1930, Whittle married his fiancée, Dorothy Mary Lee, with whom he would later have two sons, David and Ian. Then, in 1931, he was posted to the Marine Aircraft Experimental Establishment at Felixstowe as an armament officer and test pilot of seaplanes where he continued to publicize his idea. This posting came as a surprise as he had never previously flown a seaplane, but he nevertheless increased his reputation as a pilot by flying some 20 different types of floatplanes, flying boats and amphibians. Every officer with a permanent commission was expected to take a specialist course, and as a result Whittle attended the Officers’ Engineering Course at RAF Henlow, Bedfordshire in 1932. He obtained an aggregate of 98% in all subjects in his exams, completing the course in 18 months instead of the more normal two years.

His performance in the course was so exceptional, that in 1934 he was permitted to take a two-year engineering course as a member of Peterhouse, a college of Cambridge University, graduating in 1936 with a First in the Mechanical Sciences Tripos.

Power jets

Still at Cambridge, Whittle could ill afford the £5 renewal fee for his jet engine patent when it became due in January 1935, and because the Air Ministry refused to pay it the patent was allowed to lapse. Shortly after, in May, he received mail from Rolf Dudley-Williams, who had been with him at Cranwell in the '20s and Felixstowe in 1930. Williams arranged a meeting with Whittle, himself and another now-retired RAF serviceman, James Collingwood Tinling. The two proposed a partnership that allowed them to act on Whittle's behalf to gather public financing so that development could go ahead.

The agreement soon bore fruit, and in September 1935 the pair introduced Whittle to two investment bankers at O T Falk & Partners, Sir Maurice Bonham-Carter and Lancelot Law Whyte. The firm had an interest in developing speculative projects that conventional banks would not touch. Whyte was impressed by the 28-year-old Whittle and his design when they met on 11 September, 1935:

The impression he made was overwhelming, I have never been so quickly convinced, or so happy to find one's highest standards met… This was genius, not talent. Whittle expressed his idea with superb conciseness: 'Reciprocating engines are exhausted. They have hundreds of parts jerking to and fro, and they cannot be made more powerful without becoming too complicated. The engine of the future must produce 2,000 hp with one moving part: a spinning turbine and compressor.'

Lancelot Law Whyte.

Falk & Partners financed an independent engineering review that was favourable, and with that the jet engine was finally on its way to becoming a reality.

On 27 January 1936, the principals signed the "Four Party Agreement", creating "Power Jets Ltd." The parties were O.T. Falk, the Air Ministry, Whittle and together, Williams and Tinling. Falk was represented on the board of Power Jets by Whyte as Chairman, and Bonham-Carter as a director. Whittle, Williams and Tinling retained a 49% share of the company in exchange for Falk and Partners putting in £2,000 with the option of a further £18,000 within 18 months. As Whittle was still a full-time RAF officer and currently at Cambridge, he was given the title "Honorary Chief Engineer and Technical Consultant". Needing special permission to work outside the RAF, he was placed on the Special Duty List and allowed to work on the design as long as it was for no more than six hours a week.

The Air Ministry still saw no value in the effort, and having no production facilities of its own, Power jets entered into an agreement with steam turbine specialists British Thomson-Houston to build an experimental engine facility at a BTH factory in Rugby, Warwickshire. Work progressed quickly, and by the end of the year the prototype detail design was finalised and parts for it were well on their way to being completed, all within the original £2,000 budget.

Financial difficulty

Earlier, in January when the company formed, Henry Tizard, the rector of Imperial College London and chairman of the Aeronautical Research Committee (ARC), had prompted the Air Ministry's Director of Scientific Research to ask for a write-up of the design. The report was once again passed on to Griffith for comment, which was not received back until March 1937 by which point Whittle's design was well along. Griffith had already started construction of his own turbine engine design, and perhaps to avoid tainting his own efforts, he returned a somewhat more positive review. However, he remained highly critical of some features, notably the use of jet thrust. The Engine Sub-Committee of ARC studied Griffith's report, and decided to fund his effort instead.

Given this astonishing display of official disinterest, Falk and Partners gave notice that they could not provide funding beyond £5,000. Nevertheless the team pressed ahead, and the W.U. (Whittle Unit) engine ran successfully on 12 April, 1937. Tizard pronounced it "streets ahead" of any other advanced engine he had seen, and managed to interest the Air Ministry enough to fund development with a contract for £5,000 to develop a flyable version. However, it was a year before the funds were made available, greatly delaying development.

In July, when Whittle's stay at Cambridge was over, he was released to work full-time on the engine. On July 8th Falk gave the company an emergency loan of £250, and on the 15th they agreed to find £4,000 to £14,000 in additional funding. The money never arrived, and entering into default, Falk's shares were returned to Williams, Tinling and Whittle on November 1. Nevertheless, Falk arranged another loan of £3,000, and work continued.

The Gloster E.28/39, the first British aircraft to fly with a turbojet engine.

Testing continued with the W.U., which showed an alarming tendency to race out of control. Due to the dangerous nature of the work being carried out, development was largely moved from Rugby to BTH's semi-disused Ladywood foundry at nearby Lutterworth in Leicestershire in 1938 where there was a successful run of the W.U. in March that year. BTH had decided to put in £2,500 of their own in January, and in March 1938 the Air Ministry funds finally arrived. This proved to be a mixed blessing – the company was now subject to the Official Secrets Act, which made it extremely difficult to gather more private equity.

These delays and the lack of funding slowed the project. In Germany, Hans von Ohain had started work on a prototype in 1935, and had by this point passed the prototype stage and was building the first flyable design, the Heinkel HeS 3. There is little reason to believe that Whittle's efforts would not have been at the same level or more advanced had the Air Ministry taken a greater interest in the design. When war broke out in September 1939, Power Jets had a payroll of only 10 and Griffith's operations at the RAE and Metropolitan Vickers were similarly small.

The stress of the continual on-again-off-again development and problems with the engine took a serious toll on Whittle.

The responsibility that rests on my shoulders is very heavy indeed. … either we place a powerful new weapon in the hands of the Royal Air Force or, if we fail to get our results in time, we may have falsely raised hopes and caused action to be taken which may deprive the Royal Air Force of hundreds of [conventional] aircraft that it badly needs. … I have a good crowd round me. They are all working like slaves, so much so, that there is a risk of mistakes through physical and mental fatigue.

Frank Whittle

He suffered from stress-related ailments such as eczema and heart palpitations, while his weight dropped to nine stone (126 lb / 57 kg). In order to keep to his 16-hour workdays, he sniffed Benzedrine during the day and then took tranquilizers and sleeping pills at night to offset the effects and allow him to sleep. Over this period he became irritable and developed an "explosive" temper.

Changing fortunes

By June 1939 Power Jets could barely afford to keep the lights on when yet another visit was made by Air Ministry personnel. This time Whittle was able to run the W.U. at high power for 20 minutes without any difficulty. One of the members of the team was the Director of Scientific Research, David Randall Pye, who walked out of the demonstration utterly convinced of the importance of the project. The Ministry agreed to buy the W.U. and then loan it back to them, injecting cash, and placed an order for a flyable version of the engine.

Whittle had already studied the problem of turning the massive W.U. into a flyable design, and with the new contract work started in earnest on the "Whittle Supercharger Type W.1". It featured a reverse-flow design; compressed air from the outer rim of the compressor was fed into the burners and ignited, then piped back towards the front of the engine, reversing again, then finally into the turbine area. This design allowed the flame cans to be folded in length, reducing the length of the engine, and the length of the drive shaft connecting the compressor and turbine, thus reducing weight.

In January 1940, the Ministry placed a contract with the Gloster Aircraft Company for a simple aircraft specifically to flight-test the W.1, the Gloster E.28/39. They also placed a second engine contract, this time for a larger design that developed into the otherwise similar W.2. In February work started on a third design, the W.1A, which was the size of the W.1 but used the W.2's mechanical layout. The W.1A allowed them to flight test the W.2's basic mechanical design in the E.28/39. Power Jets also spent some time in May 1940 drawing up the W.2Y, a similar design with a "straight-through" airflow that resulted in a longer engine and (more critically) driveshaft but having a somewhat simpler layout. To reduce the weight of the driveshaft as much as possible, the W.2Y used a large cylindrical shaft almost as large as the turbine disk, "necked down" at either end where it connected to the turbine and compressor.

In April the Air Ministry issued contracts for W.2 production lines with a capacity of up to 3,000 engines a month in 1942, asking BTH, Vauxhall and the Rover Company to join. However, the contract was eventually taken up by Rover only.


Meanwhile work continued with the W.U., which eventually went through nine rebuilds in an attempt to solve the combustion problems that caused the engines to race and surge. On October 9 the W.U. ran once again, this time equipped with Lubbock ("Shell" type) atomizing burners which solved the racing problems, but surging continued.

By this point it was clear that Gloster's first airframe would be ready long before Rover could deliver an engine. Unwilling to wait, Whittle cobbled together an engine from spare parts, creating the W.1X ("X" standing for experimental) which ran for the first time on 14 December, 1940. On December 10 Whittle suffered a nervous breakdown, and left work for a month. This engine powered the E.28/39 for taxi testing on April 7, 1941 near the factory in Gloucester, where it took to the air for two or three short hops of several hundred yards at about six feet from the ground.

The "full" W.1 of 850 lbf (3.8 kN) thrust ran on 12 April 1941, and on May 15 the W.1-powered E.28/39 took off from Cranwell at 7:40 pm, flying for 17 minutes and reaching a maximum speed of around 340 mph (545 km/h). At the end of the flight, Pat Johnson, who had encouraged Whittle for so long said to him, "Frank, it flies." Whittle replied, "Well, that's what it was bloody well designed to do, wasn't it?"

Within days the aircraft was reaching 370 mph (600 km/h) at 25,000 feet (7,600 m), exceeding the performance of the contemporary Spitfires. Success of the design was now evident; the first example of what was a purely experimental and entirely new engine design was already outperforming one of the best piston engines in the world, an engine that had five years of development and production behind it, and decades of basic engineering. Nearly every engine company in Britain then started their own crash efforts to catch up with Power Jets.

The W2/700 engine, or W.2B/23 as it was known to the Air Ministry. The W2/700 was the first production jet engine in England, powering early models of the Gloster Meteor.

In 1941 Rover set up a new laboratory for Whittle's team along with a production line at their disused Barnoldswick factory, but by late 1941 it was obvious that the arrangement between Power Jets and Rover was not working. Whittle was frustrated by Rover's inability to deliver production-quality parts, as well as with their attitude of engineering superiority, and became increasingly outspoken about the problems. Rover decided to secretly set up a parallel effort with their own engineers at Waterloo Mill, Clitheroe. Here Adrian Lombard started work developing the W.2B into their own production quality design, dispensing with Whittle's "reverse-flow" burners and developing a longer but simpler "straight-through" engine instead. This was encouraged by the Air Ministry, who gave Whittle's design the name B.23, and Rover's became the B.26.

Work on all of the designs continued over the winter of 1941–42. The first W.1A was completed soon after, and on 2 March 1942, the second E.28/39 reached 430 mph (690 km/h) at 15,000 feet (4,600 m) on this engine. The next month work on an improved W.2B started under the new name, W2/500. In April Whittle learned of Rover's parallel effort, creating discontentment and causing a major crisis in the program. Work continued however, and in September the first W2/500 ran for the first time, generating its full design thrust of 1,750 lbf (7.8 kN) the same day. Work started on a further improvement, the W2/700.


Earlier, in 1940, Stanley Hooker of Rolls-Royce had met with Whittle and later introduced him to their current CEO, Ernest Hives. Hooker led the supercharger division at Rolls-Royce, which was naturally suited to jet engine work. Hives agreed to supply key parts to help the project and it was Rolls engineers who helped solve the surging problems seen in the early engines. In early 1942 Whittle contracted Rolls for six engines, known as the WR.1, identical to the existing W.1.

The problems between Rover and Power Jets became a "public secret" and late in 1942 Spencer Wilkes of Rover met with Hives and Hooker at the Swan and Royal pub, in Clitheroe, near the Barnoldswick factory. They decided to trade the jet factory at Barnoldswick for Rolls' tank engine factory in Nottingham, sealing the deal with a handshake. The official handover took place on 1 January 1943, although the W.2B contract had already been signed over in December. Rolls closed Rover's secret parallel plant at Clitheroe soon after, however, they continued the development of the W.2B/26 that had begun there.

Testing and production ramp-up was immediately accelerated. In December 1942 Rover had tested the W.2B for a total of 37 hours, but within the next month Rolls-Royce tested it for 390 hours. The W.2B passed its first 100-hour test at full performance of 1,600 lbf (7.1 kN) on 7 May 1943. The prototype Meteor airframe was already complete and took to the air on 12 June 1943. Production versions of the engine started rolling off the line in October, first known as the W.2B/23, then the RB.23 (for Rolls-Barnoldswick) and eventually became known as the Rolls-Royce Welland. Barnoldswick was too small for full-scale production and turned back into a pure research facility under Hooker's direction, while a new factory was set up in Newcastle-under-Lyme. The W.2B/26, as the Rolls-Royce Derwent, opened the new line and soon replaced the Welland, allowing the production lines at Barnoldswick to shut down in late 1944.

Despite lengthy delays in their own program, the Luftwaffe beat the British efforts into the air by nine months. A lack of cobalt for high-temperature steel alloys meant the German designs were always at risk of overheating and damaging their turbines. The low-grade alloy production versions of the Junkers Jumo 004, designed by Dr. Anselm Franz, would typically last only 10–25 hours (longer with an experienced pilot) before burning out, and sometimes exploded on their first startup. Whittle's designs were primitive though more reliable due to the availability of better materials by comparison. The equivalent British engine would run for 150 hours between overhauls and had twice the power-to-weight ratio and half the specific fuel consumption. By the end of the war every major engine company in Britain was working on jet designs based on the Whittle pattern, or licensed outright. Nevertheless, German axial-flow designs were influential on designs after 1945.

Continued development

A cutaway General Electric J31 (I-16) turbojet engine based on the W.1/W.2B

With the W.2 design proceeding smoothly, Whittle was sent to Boston, Massachusetts in mid-1942 to help the General Electric jet programme. GE, the primary supplier of turbochargers in the U.S., was well-suited to quickly starting jet production. A combination of the W.2B design and a simple airframe from Bell Aircraft flew in autumn of 1942 as the Bell XP-59A Airacomet.

Whittle's developments at Power Jets continued, the W.2/700 later being fitted with an afterburner ("reheat" in British terminology), as well as experimental water injection to cool the engine and allow higher power settings without melting the turbine. Whittle also turned his attention to the axial-flow (straight-through) engine type as championed by Griffith, designing the L.R.1. Other developments included the use of fans to provide greater mass-flow, either at the front of the engine as in a modern turbofan or at the rear, which is much less common but somewhat simpler.

Whittle's work had caused a minor revolution within the British engine manufacturing industry, and even before the E.28/39 flew most companies had set up their own research efforts. In 1939, Metropolitan-Vickers set up a project to develop an axial-flow design as a turboprop but later re-engineered the design as a pure jet known as the Metrovick F.2. Rolls-Royce had already copied the W.1 to produce the low-rated WR.1 but later stopped work on this project after taking over Rover's efforts. In 1941, de Havilland started a jet fighter project, the Spider Crab – later called Vampire – along with their own engine to power it; Frank Halford's Goblin (Halford H.1). Armstrong Siddeley also developed an axial-flow design, the ASX but reversed Vickers' thinking and later modified it into a turboprop instead, the Python.


During a demonstration of the E.28/39 to Winston Churchill in April 1943, Whittle proposed to Stafford Cripps, Minister of Aircraft Production, that all jet development be nationalised. He pointed out that the company had been funded by private investors who helped develop the engine successfully, only to see production contracts go to other companies. Nationalisation was the only way to repay those debts and ensure a fair deal for everyone, and he was willing to surrender his shares in Power Jets to make this happen. In October, Cripps told Whittle that he decided a better solution would be to nationalise Power Jets only. Whittle believed that he had triggered this decision, but Cripps had already been considering how best to maintain a successful jet programme and act responsibly regarding the state's substantial financial investment, while at the same time wanting to establish a research centre that could utilise Power Jets' talents, and had come to the conclusion that national interests demanded the setting up of a Government-owned establishment. On December 1 Cripps advised Power Jets' directors that the Treasury would not pay more than £100,000 for the company.

In January 1944 Whittle was awarded the CBE in the New Year Honours. Later that month after further negotiations the Ministry made another offer of £135,500 for Power Jets, which was reluctantly accepted after the Ministry refused arbitration on the matter. Since Whittle had already offered to surrender his shares he would receive nothing at all, while Williams and Tinling each received almost £46,800 for their stock, and investors of cash or services had a three-fold return on their original investment. Whittle met with Cripps to personally object to the nationalisation efforts and how they were being handled, but to no avail. The final terms were agreed on 28 March, and Power Jets officially became Power Jets (Research and Development) Ltd, with Roxbee Cox as Chairman, Constant of RAE Head of Engineering Division, and Whittle as Chief Technical Advisor. On 5 April 1944, the Ministry sent Whittle an award of only £10,000 for his shares.

From the end of March, Whittle spent six months in hospital recovering from nervous exhaustion, and resigned from Power Jets (R and D) Ltd in January 1946. In July the company was merged with the gas turbine division of RAE to form the National Gas Turbine Establishment (NGTE) at Farnborough, and 16 Power Jets engineers, following Whittle's example, also resigned.

After the war

Frank Whittle speaking to employees of the Flight Propulsion Research Laboratory (Now known as the NASA Glenn Research Center), USA, in 1946

Long a socialist, Whittle's experiences with nationalisation changed his mind and he later campaigned for the Conservative Party (especially for his friend Dudley Williams, who was Managing Director of Power Jets and became the Conservative Member of Parliament for Exeter.

In 1946 Whittle accepted a post as Technical Advisor on Engine Design and Production to Controller of Supplies (Air); was made Commander, the U.S. Legion of Merit; and was awarded the Order of the Bath (CB) in 1947. During May 1948 Whittle received an ex-gratia award of £100,000 from the Royal Commission on Awards to Inventors in recognition of his work on the jet engine, and two months later he was made a Knight of the Order of the British Empire (KBE).

During a lecture tour in the U.S. he again broke down and retired from the RAF on medical grounds on 26 August 1948, leaving with the rank of Air Commodore. He joined BOAC as a technical advisor on aircraft gas turbines and travelled extensively over the next few years, viewing jet engine developments in the United States, Canada, Africa, Asia and the Middle East. He left BOAC in 1952 and spent the next year working on a biography, Jet: The Story of a Pioneer. He was awarded the Royal Society of Arts' Albert Medal that year.

Returning to work in 1953, he accepted a position as a Mechanical Engineering Specialist in one of Shell Oil's subsidiaries where he developed a new type of self-powered drill, driven by a turbine running on the lubricating mud that is pumped into the borehole during drilling. Normally a well is drilled by attaching rigid sections of pipe together and powering the cutting head by spinning the pipe, but Whittle's design removed the need for a strong mechanical connection between the drill and the head frame, allowing for much lighter piping to be used. He gave the Royal Institution Christmas Lectures in 1954 on the The Story of Petroleum.

Whittle left Shell in 1957 to work for Bristol Aero Engines who picked up the project in 1961, setting up "Bristol Siddeley Whittle Tools" to further develop the concept. In 1966 Rolls-Royce purchased Bristol Siddeley, but the financial pressures and eventual bankruptcy due to cost overruns of the RB211 project led to the slow wind-down and eventual disappearance of Whittle's "turbo-drill". The design would eventually appear only in the late 1990s, when it was combined with a continuous coiled pipe to allow uninterrupted drilling at any angle. "Continuous-coil drilling" has the ability to drill straight down into a pocket of oil and then sideways through the pocket to allow the oil to flow out faster.

Later life

Whittle received the Tony Jannus Award in 1969 for his distinguished contributions to commercial aviation.

In 1976, his marriage to Dorothy was dissolved and he re-married to American Hazel S Hall ("Tommie"). He emigrated to the U.S. and the next year accepted the position of NAVAIR Research Professor at the United States Naval Academy (Annapolis, Maryland). His research concentrated on the boundary layer before his professorship became part-time from 1978 to 1979. The part-time post enabled him to write a textbook entitled Gas turbine aero-thermodynamics: with special reference to aircraft propulsion, published in 1981. Having first met Hans von Ohain in 1966, Whittle again met him at Wright-Patterson Air Force Base in 1978 while von Ohain was working there as the Aero Propulsion Laboratory's Chief Scientist. Initially upset because he believed von Ohain's engine had been developed after seeing Whittle's patent, he eventually became convinced that von Ohain's work was in fact independent. The two became good friends and often toured the U.S. giving talks together.

In 1986 Whittle was appointed a member of the Order of Merit (Commonwealth). He was made a Fellow of the Royal Society, and of the Royal Aeronautical Society, and in 1991 he and von Ohain were awarded the Charles Stark Draper Prize for their work on turbojet engines.

Whittle died of lung cancer on 9 August, 1996, at his home in Columbia, Maryland. He was cremated in America and his ashes were flown to England where they were placed in a memorial in a church in Cranwell.