A CAREER INSPIRATION
DR. RICHARD MARSH C. LAUDS THE P1’S LEGACY.
“Mayday, Mayday...this is Skybus 1…I am under attack from 6 Soviet MiGs…Mayday Mayday.”
When I heard this call, I was flying my English Electric P1B at just below the speed of sound along the East German border. It was the period of the Cold War, sometime in the mid-1950s and I knew that Skybus 1 was a lumbering NATO troop transporter en route to Berlin.
I replied immediately – “Hello Skybus 1. This is Tiger Leader altering course to intercept the enemy.” Without any concern for my own safety, I slammed the throttles forward to engage full reheat, accelerated to Mach 2.5 and did a fairly improbable 15g right turn towards the enemy. Moments later I caught sight of Skybus 1. Smoke was streaming from the transport aircraft’s engines and six MiGs were buzzing around it. “Tally Ho…Tally Ho… bandits dead ahead,” I shouted excitedly on the aircraft radio as, with my two 30mm cannon armed and ready to fire, I closed in.
Then disaster struck: I hurtled at high speed into an elderly pair of female knees. There was a yelp and a cup of hot tea descended over my head and onto my precious English Electric P1 balsa wood model. My severe and unforgiving maiden aunt was far from amused and she turned to my mother and said: “Apart from being a terrorist, what is young Richard going to do when he grows up?”
My mother pondered this question as she mopped up tea and soggy biscuits from the carpet and said: “Can’t you see – either he’s going to fly aeroplanes or build them. He’s absolutely mad about the things.”
My mother’s prediction was prescient. Just over a decade later, in 1967, as a raw young engineering graduate I presented myself at the gates of Filton House in Bristol to join the British Aircraft Corporation’s Concorde design team. Looking back nearly half a century later I have no doubt that one of the principal inspirations in my choice of career was that remarkable range of aeroplanes from English Electric Aviation Limited: the P1A and the P1B which evolved into the Lightning fighter.
The biplane Gloster Gladiator was still in front-line service with the Royal Air Force in 1940. In 1947 the Ministry of Supply produced Experimental Requirement 103 which led directly to Britain’s only supersonic fighter of the era – just seven short years from biplanes being used in combat to the requirement for an aircraft which, with modern engines and avionics, would still be a serious contender in the 21st century; quite astonishing.
English Electric was one of the founder companies of the British Aircraft Corporation, and the men primarily responsible for the P1 and the Lightning were W.E.W. ‘Teddy’ Petter (also father of the Canberra and the Gnat), Freddie (later Sir Frederick) Page, and a brilliant aerodynamicist called Ray Creasey. During my happy career on the Concorde Supersonic Transport (SST) project I came to realise just how much of the Lightning’s DNA had percolated through to our magnificent Concorde machine. This was apparent not only in the aerodynamics, structures and systems of Concorde, but also in the way we went about conceiving and testing supersonic aircraft, even down to the very tools that we used. There were several examples of this. For instance, the airflow over the P1’s wings was very similar to Concorde’s in that we depended on the profile of the leading edge to create the low pressure vortices above the wing. This pioneering work on the P1 was certainly instrumental in the success of the SST concept. There was also a direct link. I was delighted to discover an assembly shop full of Lightning tools, jigs and equipment at Filton because the forward fuselages of all 20 dual-seat Lightning T5s were built there by the same men who went on to build Concorde. Overall, a total of more than 330 Lightnings of various marks were produced.
The mathematical analyses required in the design of the P1B/Lightning and Concorde were surprisingly similar. Slide rules and mechanical adding machines were the order of the day. A device that could have worked out square roots accurately and quickly would have been worth its weight in weapons-grade plutonium. In those days it was an iterative process of guesswork until you got sufficiently close to the answer. Today’s free calculators given away on key-rings in Christmas crackers would have saved us hundreds of thousands of pounds – a lot of money back then! Some of the unwitting, or perhaps instinctive, design features of the P1 came to be recognised in later years and given posh names, but they were already there in Teddy Petter’s original concept. For instance, the area rule concept (constant cross-sectional frontal area along the length of the aircraft) later much vaunted by the Americans, was a feature of the layout along with a much more extreme wing sweep than that used in other contemporary fighter aircraft designs.
This high degree of sweep, 60 degrees at the leading edge and 52 degrees at the trailing edge with only a 5% thickness ratio, kept the wing well behind the main shock waves. It also effectively spread the frontal area of the aircraft along its length, thus conforming to the area rule principle. A brilliant feature of the aircraft’s engineering was just how ‘right’ the detailed design was from the very start. There was the famous day when the wing was statically tested to the point of failure. The load level was increased from 50% to 75% and then up to 95% of the predicted failure point when alarming creaks and groans could be heard from the structure. Eventually the 100% load level was reached and five seconds later there was a loud bang when part of the wing structure failed. It was impressive that this complex and advanced wing, where load paths were extremely difficult to predict, had precisely reached its design target. Many years later I found myself using techniques that the P1 design team were applying every day to solve the problems of structural strength and failure. For example, by removing metal rather than adding it, the overall strength and flexibility of an aircraft structure could be increased. Over-strong components acted as stress raisers whilst components that were too flexible transmitted the load to stiffer areas. We found that by weakening the over-stiff parts to create uniform stiffness and flexibility this worked wonders for weight-saving and fatigue life.
The genius of the original architecture of the P1 was apparent from the fact that the major details of the layout were frozen as early as 1951. The Sapphire engines (later Avons) stacked and staggered to reduce frontal area, the wing plan-form mounted at shoulder height, the 5% thickness profile and the all-moving tail plane mounted low down on the fuselage to operate in clear air – all remained unchanged through to the final mark of Lightning. It is worth emphasising the ingenuity of the engine layout. The stacked and staggered arrangement gave 100% increase in power with only a 50% increase in frontal area – brilliant!
A further bonus of the P1/Lightning programme was the development of supersonic wind tunnels. Although small in cross section and powered by early centrifugal gas turbines, these wind tunnels could test aircraft profiles up to Mach 1.7 which was revolutionary in the early 1950s. From these wind tunnel tests another important P1/Lightning ‘first’ was established: the aircraft would be capable of supercruise – the ability to cruise at supersonic airspeeds without the use of after-burners, something that was vital to the range (and economics) of Concorde many years later.
Without the use of computers in the design phase, the ultimate accolade to the engineers’ work was that, in flight, the aircraft performed and handled almost exactly as had been predicted. This probably had a lot to do with the point that, very unusually, the legendary English Electric test pilot Roland (Bee) Beamont was invited to be an integral part of the design team from day one. Beamont was the first English pilot to fly an aircraft through the sound barrier which he did in an F86 Sabre. The P1s and the Lightning flew smoothly through the transonic phase which made the whole idea of a future supersonic passenger aircraft entirely credible. Of course the performance of the Lightning was remarkable, as suggested later by a flippant comment from a service pilot: “I was fully in charge, then I let the brakes off!”
The flight test programme for the P1A and P1B went smoothly apart from the embarrassing loss of a few canopies due to the aeroelastic deformation of the canopy rails. Fortunately this did not result in any injuries. The only major changes for the production Lightning were the altered air intake to accommodate the Ferranti Airpass radar, a raised pilot seat and a larger fin. The Lightning was born – and what an aircraft it was! Designed for just ten years of Royal Air Force service, it actually completed 28 years from 1960 to 1988 during which time the Lightning never fired a shot in anger, unlike just about every one of its predecessors and successors. Famously, the Lightning shot down just one aircraft – one of ours! A pilot had ejected from his terminally ill Harrier which was flying towards a population centre so a Lightning was sent up to despatch the Harrier, a task duly achieved.
The Lightning was renowned for its ear-splitting and spectacular vertical climb at just about every air show at which the aircraft was demonstrated. I will always remember a fabulous ‘Diamond Nine’ display by 74 Squadron. The high speed, near silent approach with white water vapour shimmering over their wings was a beautiful sight to behold. Then came that overwhelming wall of sound as the Lightnings drew level, stood on their tails and seemed to climb into the heavens forever. The din should have woken the dead for 50 miles around and the emotional impact was palpable. Many moist eyes in the crowd were being wiped after that display.
This performance, though, was more than just a crowd pleaser – it was real. Whilst the Lightning could not maintain its astonishing initial rate of climb of 50,000 feet per minute, the aircraft could easily reach an altitude of 40,000 feet in 2.5 minutes and there are recorded instances of Lightnings, with missiles fitted, climbing to over 85,000 feet. This was the territory of the Lockheed U-2 high altitude reconnaissance aircraft with its 103-feet wingspan and must have caused considerable surprise and alarm to any United States U-2 pilot who found a British colleague grinning at him from alongside.
The Lightning has beaten the McDonnell Douglas F15 Eagle up to 30,000 feet and out-climbed many other later aircraft like the McDonnell Douglas F4 Phantom, the variable-sweep wing Grumman F14 Tomcat, the General Dynamics F16 Freedom Fighter, the Dassault Mirage III, the variable-sweep wing Panavia Tornado and last, but not least, the Mikoyan-Gurevich MiG-21 (NATO code-named ‘Fishbed’). It has been said that the Lightning was the fastest pilot-only aeroplane ever built in that the machine lacked sophisticated on-board computers – the pilot had to do it all. Today’s combat aircraft are designed to be inherently unstable with stability only achieved by two or three computers working in parallel to obey the pilot’s instructions. If the computers fail most of these aircraft will become unflyable. The Lightning was the most manoeuvrable Mach 2 fighter of its generation. One of the trickier aspects about flying it, however, was landing in a crosswind at nearly 200 mph, the skinny tyres always making that a bit of a lottery, particularly on a wet runway.
The Lightning, because of its complexity and the packaging density of its systems, was difficult and highly labour-intensive to maintain. There’s a worst case report of one thousand hours of maintenance required to achieve just one flying hour. Hopefully this was the exception rather than the rule. The Lightning story would not be complete without mentioning the rather grim statistic that crashes and other accidents accounted for more than a third of the aircraft built; for various reasons nearly 120 Lightnings were lost over its service life. The single major cause of loss was fire, both in the air and on the ground, which accounted for 33 aircraft. Undercarriage problems disposed of a further 18 aircraft, six were lost in mid-air collisions, two ran out of fuel and one aircraft somehow or other managed to ingest a display banner.
If money was no object it would be interesting to fit a Lightning with modern electronics and more fuel efficient engines. These measures would overcome the aircraft’s two major deficiencies and the Lightning’s performance could still embarrass most military aircraft flying today. Even the P1A, with its early engines, could top 1,000 mph, the P1B nearly 1,400 mph and the Lightning over 1,500 mph.
It may surprise people to learn that Concorde’s potential as a supersonic bomber was the subject of a brief and classified study in the British Aircraft Corporation. This came to nothing because it soon became obvious that a few squadrons of Concorde would have consumed the entire defence budget twice over. The Polaris submarine-launched missile with its multiple re-entry warheads was a much more cost-effective deterrent. However, it amuses me to think that the one aeroplane which could have caught and destroyed a Concorde bomber was the Lightning, conceived when I, born in the Second World War, was just four years old. The Lightning was an astonishing aeroplane and a wonderful example of British engineering genius at its very best.