Altogether the opposition to Concorde was an interesting social phenomenon. Many people went to surprising lengths to damn the aircraft, one argument being that the engines would eat up ozone in the upper atmosphere and cause widespread skin cancer from the incoming cosmic rays. Obviously, far fewer harmful radiations reach the Earth’s surface than those passing through the flight and cabin crews who spend their lives aboard Concordes, and the airlines say that these crews are a very fit group of people!
It has been my great pleasure to make many trips in Concorde, but I shall never forget the opening of scheduled services by British Airways on 22 January 1976. Only one country in the world would receive the aircraft at that time, and so the route went to Bahrein. Our party was led with extreme skill and charm by HRH The Duke of Kent. After an avalanche of champagne and rousing speeches by Ministers we took off and flew at Mach 0.92 across Europe (which, incidentally, itself saves about 40 minutes compared with other jets) until we turned on the reheat at the head of the Adriatic. As we went through the dreaded ‘sound barrier’ the only effect was that the big digital readout changed from 0.99 to 1.00, but when it got to 2.00 everyone cheered and down the hatch went another deluge of champagne. We arrived after a flight of 3¾ hours, compared with about 8 by the regular jets.
We were delighted to be invited to a banquet at The New Palace by HH The Amir of Bahrein. The fairytale palace was a blaze of lights, and the bodyguard were a blaze of exotic uniforms. We were individually presented; His Highness was a little man with brilliant twinkling eyes, and my spirits rose further as he said ‘I am very glad to have you in my country’. Eventually we entered the fabulous dining room, ritually washed our hands and took our places around the gigantic U-shaped table. I was next to the Minister of Foreign Trade, who spoke perfect English. We each had a waiter in full court uniform, each pair of guests being supervised by a steward. We drank fizzy orange, but the dishes were too numerous to study. The one thing that caught my eye instantly was that every few feet was a complete boiled lamb.
I was about to turn to the Minister and say ‘How far-sighted and generous of your government to allow us to bring the Concorde here on its first scheduled flight’, when he said to me ‘What a great honour you have done our country by bringing your magnificent Concorde here on its inaugural flight!’ Considering the violent hullabaloo that was going on in New York, and that nobody else would allow us in, it was difficult to find the right answer! The waiters kept our plates well filled but there was no move to carve up the lambs and I began to fear they were only for decoration. So I asked my host how they were cooked, and he told me ‘In the old days they were boiled in large pots, but now we use pressure cookers. Would you like to try it?’ That was precisely what I was angling for, and it proved to be lovely, yet I was the only one to eat any of it.
It was my first experience of Arabian hospitality. I was deeply impressed by their generous, cultured and highly dignified behaviour. We have much to learn from them.
No engine in history has ever been developed like the Olympus. The original design figure in 1946 was 8,000 lb, yet the Concorde engine gives well over 30,000 lb and has been run with reheat at 40,000 lb, the highest thrust of any production turbojet in the world. It is a comment on the inability of engine designers to think of everything to note that when we first ran the Olympus 593 oil cost $1.50 a barrel, and when it entered airline service it cost $30 a barrel. This, together with the refusal of countries to permit it to fly supersonically over land, killed the Concorde as a commercial proposition, despite the excellence of its design.
Chapter 9
The Orpheus
During World War 2 the Chief Designer of Westland Aircraft was W. E. W. ‘Teddy’ Petter. He used Rolls-Royce engines in his Whirlwind and Welkin twin-engined fighters. In 1944 he was enticed up to Preston by Sir George Nelson, boss of the giant English Electric company, which had a massive aircraft factory building Halifax bombers for the war and later Vampires, but no design team. His brief was to set the company up as a producer of military aircraft of its own design so that it did not have to rely on a world war in order to fill its vast factories making other people’s designs.
Petter had already begun to scheme a replacement for the Mosquito using jet propulsion. Preston was not far from Barnoldswick, and in 1946 he often came to see me, and I encouraged him to think in terms of a twin-engined aircraft with two Avon engines. His design became the Canberra, which swept all before it, and even appeared in America built by the Martin Company as the licensed B-57 version with Wright’s J65 (licensed Sapphire) engines. In 1947 he launched a project for a supersonic research aircraft which eventually led to the Lightning Mach 2 interceptor, with two reheated Avon engines. He then quarrelled with the management, mainly because he wanted to have control over experimental manufacture.
It has always been debatable whether it is a good policy to divide a factory into two watertight compartments, one for design, development and research and the other for all manufacturing. Some engineers adhere strongly to the view that, if you leave experimental manufacturing — which is the lifeblood of advancing technology — to the Production Department, it will never get done, because the priority will be churning out today’s products for customers. But the production people argue that they alone have the contacts with the material and equipment suppliers, and the ability to make the best use of manufacturing facilities.
Rolls-Royce favoured the second view, and I always agreed that engineers have enough problems without taking on the added burden of controlling manufacturing resources. Petter thought the opposite, and when after a long battle he failed to get his way he left Preston and in 1951 became Managing Director of Folland Aircraft, a small company based at Hamble which at that time was owned by my great friend Charles Hill, chairman of the famous Bristol shipping firm. (Later it was absorbed into the Hawker Siddeley Group). At Hamble Petter was monarch of all he surveyed, and he settled down to design the beautiful little Gnat light fighter.
Petter had become convinced that fighters were becoming too large and heavy, and thus too complicated, expensive and difficult to keep serviceable. Later the suggestion was made in print that he was motivated more by the available skills and financial resources at Hamble, but to me he was always championing a sincere cause in his advocation of a much smaller, lighter and cheaper fighter which could outfly any opponent. Many in NATO thought the same way, and both NATO and the British government approved the basic idea.
Thus in late 1952, Petter was determined to build the Gnat, and approached me at Bristol to produce a suitable engine. I was very keen to support him, as I knew from my Ilkley calculations that it should be quite possible to design a simple axial engine weighing about 800 lb and giving 5,000 lb thrust, which filled Petter’s requirement exactly.
I had a much more personal reason to go ahead. Up to this point in my career, I had given my effort to the perfection of other people’s basic designs, i.e. the Merlin of Sir Henry Royce, the W.2B of Frank Whittle, and the Proteus and Olympus of Frank Owner. I felt that by now I had served a sufficient apprenticeship to embark on my own designs, and I was eager to do just that.
At this point let me emphasise that designing, developing and producing is a team effort. It needs a whole army of highly qualified engineers and administrators, specialists in aerodynamics, mechanical design, the strength of materials of all varieties, combustion of fuel, with the attendant fuel system, and, last but not least of all, a body of competent designers who can incorporate all of the advice the experts give them into one comprehensive whole, which can manufactured by the facilities available in the factory. It goes without saying that someone has to find the money to pay for all this!
The job of the Chief Engineer can be likened to that of the conductor of such a vast orchestra — he has to bend the performance to his ideas and scoring and supervise many ‘rehearsals’ when the design is in progress. The supporting players are vital, and their contribution is often unsu
ng. They get their satisfaction when the engine runs and flies just as they foresaw. Neither I, nor anyone else today, can be said to be totally responsible for the ‘design’ of an aero engine.
To return, I knew from my Ilkley calculations that there was no intrinsic difficulty in producing an engine weighing only 800 lb yet able to give a thrust of 5,000 lb. In keeping with the light-fighter concept the engine needed to be simple, without any attempt to attain a high pressure-ratio, because for a short-range fighter the fuel saved would be more than outweighed by the greater engine weight. But it was apparent that providing an engine for the Gnat offered opportunities to rethink axial engine design and introduce a number of novel features.
One was the elimination of the centre bearing. Previous axials, including the Avon, Sapphire and Olympus, had three main shaft bearings, one at each end of the compressor and the third at the turbine. According to Euclid a straight line is the shortest distance between two points, not three, and for this reason it is impossible to keep all three bearings absolutely in line. The main rotating assembly has to be split into front and rear sections joined by a coupling able to allow for small misalignments. In the design of the BE.26 Orpheus we adopted a short seven-stage compressor driven by a single-stage turbine, and it was desirable to eliminate the centre bearing. Doing this in ordinary engines would lead to the main drive shaft suffering from whirling, bending outwards and whipping around like a skipping rope. But we made the drive shaft in the form of a thin-walled tube more than 8 inches in diameter. It was surprisingly light, and had a critical whirling speed much higher than any possible excitation from the engine.
Leaving out the centre bearing and its attendant coupling meant we could also leave out the strong supporting structure, a lubrication system, a sealing system to prevent escape of oil, and, in most engines, also an air cooling system. This simplification saved not only weight but also cost and extra maintenance.
We also devised a new method of construction for the compressor rotor. The blades were slotted into aluminium discs which were then separated by spacer rings. The assembly was dowelled together for concentricity and fastened lengthwise by steel bolts.
A new method of mounting the turbine on the large-diameter shaft was devised. The disc was provided with precision-machined radial splines, which engaged in similar splines on the face of the shaft. This ensured very accurate concentricity whilst allowing for the radial expansion of the disc and shaft due to temperature and centrifugal force. This was a most successful innovation, and for the first time it was possible to remove and replace a turbine without having to rebalance the whole assembly.
The combustion system was of the cannular type, a single outer casing containing seven flame tubes. These also broke new ground in that the downstream portion of each incorporated one-seventh of the turbine entry duct, complete with the stator blades (called vanes in the USA). This duct conveys the hot gas from the combustor to the turbine. Previously it had been made of a combination of steel castings and refractory sheet-metal parts fabricated by welding. Not only did this part of the engine often give a great deal of mechanical trouble, due to cracking and distortion, but it was heavy, difficult to manufacture, expensive and unreliable. The neat Orpheus design eliminated these troubles in one go, because the individual chambers were merely held together by a simple bolt, which allowed for expansion without stress.
A stroke of good fortune was that cancellation of the Princess programme in 1953 freed an excellent Bristol designer, Bernard Massey, who for many years had led a section working on the giant flying-boat’s air-conditioning plant. He was thus able to take on the Orpheus, leaving Marchant and the main design office working on the Olympus and Proteus engines, and the project officially got going in December 1953. I spent many fascinating hours with Bernard at the drawing board trying to get the design down to our target weight of 750 lb. The initial design stage costs little money, but the obvious question was: who was going to pay when the Orpheus moved into the hardware stage, and the thousands of pounds became hundreds of thousands or even millions? Not the RAF, who wanted ever bigger and more costly fighters, of which they could afford fewer and fewer.
Unknown to us, the Gnat proposal had caught the attention of Col Johnnie Driscoll, USAF, head of the MWDP (Mutual Weapons Development Program) office in Paris. MWDP was a US organization set up to organize projects within NATO, and bring in additional nations who had weak industrial strength. The NATO Supreme Commander was Gen Lauris Norstad, also of the USAF, and he was very interested in light fighters, partly because they could be dispersed widely away from the vulnerable airfields and partly because they were within the industrial capability of many nations, including the rebuilt Italy and West Germany. Driscoll therefore convened a meeting of NATO aircraft companies where they were given details of a requirement for a light tactical strike fighter weighing around 8,000 lb and able to take-off and land in less than 2,000 ft, in what Driscoll called ‘cow pastures’. At this time, all jet fighters required a concrete runway of at least 5,000 ft, and as such were vulnerable to the new missiles, which were just appearing.
This NATO requirement was based on Petter’s concept of the Gnat, and thus he had the ball right at his feet. However, there was just one stumbling-block. The Gnat had high-pressure tyres, for concrete runways. In vain did I plead with him to change to low-pressure tyres; his response was always that he could not do it, because the larger bays to house the retracted wheels would spoil the drag of his fuselage. In desperation I urged him ‘Just say that you will try to do it’, but Petter had had a Quaker upbringing and could not stretch the truth in the slightest. So the Gnat was eliminated and the NATO Light Fighter competition ended up between Dassault, Breguet and Nord in France and Fiat in Italy, with British firms showing no interest. France’s Sud-Est Durandal and Sud-Ouest Trident dropped out, as did Nord, leaving Breguet to build the Taon (French for horsefly but an anagram of NATO), Dassault the Etendard and Fiat the G91. And the satisfying thing for us was that all three finalists chose the Orpheus as their engine, so Driscoll was able to dip into his pile of dollars and assist us to develop the engine. The MWDP deal was that they would pay for 75% of the costs if the developing country would find the rest. As Whitehall showed no interest, I had to ask Verdon, and he readily agreed to pay for 25% of the cost of developing the Orpheus with company funds. I at once hastened the programme into the manufacturing stage, with Massey assisted by John Dale, an experienced development engineer who had recently joined us from Derby.
At this point I re-established my friendship with Theodor von Kármán, which had begun at Cambridge in 1934. In 1933 von Karman had left Aachen, where he had been Professor of Applied Mechanics, for Pasadena, California. Though he was a brilliant mathematician with many interests, his first love was aeronautics and at Pasadena he had rapidly risen to being No. 1 aeronautical expert in the whole USA. He had rendered them great service as Chairman of the USAAF Scientific Advisory Board before and during World War 2, and had been held in great respect by successive Presidents of the United States. But at heart he was a European, and after the war he came back to Paris to act as Chairman of AGARD, the NATO Advisory Group for Aeronautical Research and Development.
He was a batchelor, and at Aachen had loved to follow the German professorial tradition of drinking with his students in the bier-kellers. In Paris he was invariably accompanied by an entourage of young, and not so young, ladies, who were chaperoned by his sister. They all adored him, for he was charm personified. I cannot resist telling a story that sums up his philosophy. After a very good lunch he returned to his office to be admonished by his secretary for missing an appointment. He asked ‘What does it matter, when I have discovered the secret of a happy life?’ ‘What is that?’ inquired his secretary. ‘Why, a Japanese maid, a Hungarian cook and a French mistress.’ Plaintively the girl asked ‘Don’t we Americans get anything?’ ‘Of course, one would need to have an American washing machine.’
Since the tota
l US investment in the Light Strike Fighter and the Orpheus engine amounted to millions of dollars, von Kármán was asked to serve as overall technical adviser. Because I knew him so well he spent much time with me examining the design and the progress of the Orpheus, to which he finally gave his enthusiastic support. The first engine ran in early 1955, and since every one of the radical design innovations worked like a charm its development was rapid. In January 1956 it was Type-Tested at 4,000 lb thrust, in November 1956 the first production series was Type Tested at 4,520 lb and in May 1957 the first of the Mk 800 series — identical except for a fuel pump of increased capacity — was Type Tested at 4,850 lb. The first development engines all weighed just about 800 lb, and I was particularly pleased that we had got back to the speed of development of the Derwent V and Nene. There was one big difference: while those earlier engines gave about 3 lb thrust for each pound of weight, as did the axial Avon and Sapphire, the Orpheus pushed this ratio up to 6 lb! In fact, it was well into the 1980s before this ratio of thrust to weight could again be equalled, except by the Pegasus which was pretty much developed by the same team, as noted in a later chapter.
In the battle for the NATO aircraft the Fiat contender had an advantage that the irritated French lacked. The company’s technical director, the great Giuseppe Gabrielli, had been von Karman’s pupil at Aachen in the 1920s, and so the man he called ‘the maestro’ gave him every possible encouragement. When it was announced that the G91 had won the competition — and justly so on its merits — the French angrily refused to have anything to do with the programme.
Fortunately the G91 proved to be a sound and well-engineered aircraft which had a very long and popular career. Many were made in Italy and West Germany, and some are still serving in Portugal. The Orpheus 803, rated at 5,000 lb thrust, was made in large numbers both by Fiat in Italy and KHD (Kloeckner-Humboldt-Deutz) in West Germany to power the various G91 versions. Norstad got his wish of an emergent European industry, and the first 100,000 hours flown by the Luftwaffe after 1945 were flown largely on the G91. It is a pity we cannot have a few more Colonel Johnnie Driscolls to knock NATO heads together. He was a likeable genius at getting collaborative programmes going. With Air Marshal Sir Neil (Nebby) Wheeler, I attended many of his light fighter progress meetings in Paris, London and Turin.
Not Much of an Engineer Page 21