Sunday, August 2, 2009

Chapter 9: Farewell to England



The Lightning was designed as a Mach 2 intercepter, and flight testing included flying not only with Red Top missiles, but rocket packs under the nose, on pylons under the outer wings, and even overwing stores.


I still found flight testing to be an exciting and spectacular environment. The Lightning, with its twin Avon jets in full reheat, had a performance which was years ahead of any other fighter, and Roland Beamont’s practice demonstrations before each Farnborough airshow were guaranteed to stop work in the Flight Test office for the duration of the demonstration as the Lightning scorched round inside the airfield boundary at Warton with both afterburners thundering. Lightning take-offs were similarly awesome, with the silver aircraft rotating to climb almost vertically from the runway, balanced on a pair of spears of yellow flame studded with diamond shockwaves. Warton was busy with Canberras being ferried abroad, Lightnings being delivered to Saudi Arabia, and refurbished Lightnings being returned to the RAF.
My responsibility for aircraft handling led to some interesting projects. The RAF had lost a number of Lightnings due to high-angle-of attack departures and spins. Spinning trials of the Lightning revealed that despite the sheer massiveness of the Lightning and its unconventional sixty-degree swept wing, its spinning behavior proved to be largely conventional. As with all heavy jets, the loss of altitude per turn during the spin was awe-inspiring, but the specified recovery action worked every time. I spent many hours with aerodynamicist Sandy Burns incarcerated in a telemetry van parked out on the airfield while pilots Tim Ferguson and John Cockburn spun the big fighter over the Yorkshire Moors.
However the big Lightning had other problems. One was a tendency to have reheat fires in service. This struck close to home when one day I watched John Cockburn take off in Lightning F53 53-690 on its 4th flight, prior to delivery to the Saudi Air Force. Only a few minutes later the phone rang in the flight test office. It was the Warton Control Tower to inform us that the Lightning had crashed. Apparently a reheat fire had developed, the pitch control system failed, and as a result the aircraft had gone into a steep and uncontrollable climb. Cockburn had ejected from the crippled jet and come down unharmed by parachute, while the Lightning had crashed at Pilling, some ten miles North of Warton.


But then we started to break new ground with the Jaguar. The Jaguar had a number of design innovations. It had been designed jointly by French and British Design teams to satisfy a variety of requirements laid down by the French Air Force and the Royal Air Force. The various conflicting requirements sounded like a recipe for disaster. Intended to be an economical strike aircraft in a single-seater version, and a supersonic trainer in the two-seat version, the Jaguar had heavy-duty landing gear and full-span flaps to enable it to take off from short grass fields.
The choice of this flap system left no space for conventional ailerons, and roll control was achieved using spoilers on the upper surface of the wing. The spoilers resulted in some idiosyncrasies in roll control being encountered during early flying and a lot of development flying was spent in ironing out these problems, and modifying the existing rolling tail.
Directional stability was initially inadequate and the vertical fin was enlarged, and ventral fins added under the rear fuselage. In company with other swept-wing jets, the Jaguar proved to have a wing rocking problem if pulled hard into a turn. Autostabilizer modifications cured this.
If this sounds like a litany of disastrous proportions, it was not. These problems were encountered largely around the edges of the flight envelope and were typical of any new aircraft under development. This was the reason for flight test. The Jaguar proved a very effective strike aircraft under program Manager Ivan Yates.







Jaguar flying fast and low, with a typical load of bombs on board. Jaguar testing was split between Warton in the north of England, and Istres in the south of France. We commuted frequently on the company HS.125 business jet in order to speed up the testing.


During the Jaguar design phase we had learned that North American had been carrying out spinning trials on their big A-3J Vigilante and had found that the big jet had a very oscillatory and unpleasant spinning mode. As the Jaguar configuration similarly had a swept wing mounted high on the fuselage, it looked as if it might exhibit the same behavior.
An extensive program of wind tunnel model testing was carried out in the vertical wind tunnel at Lille in France, supplemented by free-flight model tests in England, where large models of Jaguars with control preset to force the model into a spin were dropped from helicopters over the Larkhill range. The models spun beautifully.
Eventually the spinning trials were transferred to the full-size aircraft. Prototype M 05, the French maritime Jaguar, was used for these trials, flying from Istres, in southern France. This meant that I spent an increasing amount of time commuting in the company HS 125 between Warton and the South of France. Istres was the French Air Force test base, comparable with Edwards AFB in California, and was a veritable storehouse of strange prototype aircraft. Dassault were flying their variable sweep Mirage and the Mirage F1; the Mercure airliner and the Falcon bizjet.
At the working level the French and British Flight Test Teams working on the Jaguar program co-existed profitably throughout the program. French pilots flew our Jaguars, British pilots flew theirs. Lunches at Istres took some getting used to however. We were invariably taken to a restaurant off-base by their pilots for a leisurely and stylish lunch, complete with an unending supply of the best local wine. We learned to complete out business prior to lunchtime.
The main difference in technique between British and French methods of testing was the spinning trials. Whereas in England our spinning was done over uninhabited moorland, at this desert airfield at Istres the spinning trials took place directly over the field, starting at 45,000 feet, primarily to obtain good kine-theodolite coverage of the gyrations of the aircraft. It was an unsettling feeling to stand on the balcony of the flight-test building and squint up directly overhead into the clear sky, where the sunlight flashing on the rotating aircraft traced the inexorable descent of the jet…
But all went well, and M 05 recovered every time, although the predicted oscillatory spin was encountered and gave the pilots a rough ride before the aircraft recovered. Jaguar testing went on apace, with many different stores combinations being tested on the British and French prototypes. Jimmy Dell, Paul Millett, Tim Ferguson, Dave Eagles, John Cockburn and Jerry Lee carried out the bulk of the flying.
The Jaguar had a very sophisticated weapon aiming and delivery system for its time. Ultimately the aircraft entered RAF and French Air force inventories as a successful strike aircraft. One of the last Flight Test projects on Jaguar was to operate Jaguar S07 from the newly constructed M 55 motorway near Blackpool in a successful demonstration of its operating versatility, with Tim Ferguson the pilot on this occasion. The aircraft was landed on the load, refueled and bombed-up under a bridge and dispatched back to Warton with no fuss at all.






As a demonstration, a Jaguar was landed on a section of the soon-to-be-opened M-55 motorway a few miles from Warton. It was taxied under a bridge for cover, bombed up and launched back to Warton, showing how this could be done in wartime.

By now flight test was gearing up for the Tornado. Another supersonic strike aircraft, again it had a new engine, the turbofan RB 199. The first prototype flew in Germany, but the second and third prototypes flew from Warton. The Tornado was our introduction to an even more complex aircraft. Pilots and engineers all attended ground school to learn about the complexities of the swing-wing aircraft. Testing started well, but the red and white prototype P02 was nearly lost when one of the engines swallowed a seabird as the aircraft was overflying the airfield during a planned low-speed trial. Pilots Millett and Eagles had a worrying few moments before they managed to accelerate away on the remaining good engine to a reasonable flying speed.
P02 gave us more anxious moments. Flutter testing had been delayed for months until special flutter stores were built and attached to the underwing pylons. On a flight with Paul Millett piloting and Flight Test Engineer Dave Williams in the rear seat the swing wings refused to swing forward to the low-speed position for landing. Our runway was not long enough to cope with a heavyweight Tornado landing with wings swept at 45 degrees without benefit of the sophisticated flap/slat system, so eventually the stores had to be jettisoned into the sea. The resulting landing with the wings still jammed in the mid-position went well. There was a delay to the program because of the lack of the flutter stores.

One of our flight test Tornadoes. With a swing wing, brand-new RB.199 turbofan engines and a complex flight control system, our flight test program kept the team busy.


Flight Test worked with all of the other departments and with Gary Willox, the Tornado Program Manager. Each morning all department heads would meet to report on the previous day’s progress and to be apprised of the progress of the tri-national program. With flight testing, development and production simultaneously being carried out in Germany, Britain and Italy, just keeping track was a complex task.
Avionics prototype P08 became my primary responsibility, and it was a different experience for me to monitor the test flying from a control room. This was a trainer version with controls in the rear cockpit. However, as it happened my time in the rear cockpit of the Tornado was to be limited. Now I spent most of my time in the control room, where I sat at my console backed by a team of engineering specialists, all sitting at their own computer screens. With a multiplicity of sensors on the aircraft, we often had more depth of information available to us than did the pilot. We could constantly take the pulse of the aircraft, displaying engineering, performance or engine parameters onto our screens. It provided much more information on every flight, and enabled us to advise the aircrew if problems or failures occurred.
This was now a world of complex systems and checklists. Displays in the cockpit were duplicated in our control room. If a malfunction occurred, lights and audio alarms demanded instant response. It was a world in which we were fenced in with limits that were not to be exceeded. Test flying was a world of disciplined flight above all else. Flight crews had detailed schedules to follow. Back-up schedules were devised in case the primary test points could not be achieved. Engineers on the ground monitored the flight and could advise me if any parameter looked as if it was going out of limits. Every second of flight was used for gathering data, and every second of flight was used to the full. To this end, flight refueling was often used to keep the Tornado airborne as long as possible to collect even more data.
It bore very little relationship to the freedom of turning the world upside down in a moment of exuberance in an aerobatic biplane, thermaling over a quiet countryside in a sailplane, or wheeling over the countryside in a light aircraft for the last few precious minutes of flight before dark.
The summer of 1976 found me still flying light aircraft at weekends but yearning for something more challenging than the regular flying club aircraft. In partnership with John Scott and Barry Parkinson I entered into a project to build a Baby Great Lakes biplane. With an 0-200 engine and only a sixteen foot wingspan, it promised to be a good little aerobatic mount. We mailed off to the USA tor the plans and in due course started to build the aircraft in John’s garage. The tail unit took shape first, then the welded steel tube fuselage and the wings started to come together. Each of the four wing panels comprised a dozen or so wooden ribs, each built up from individual pieces of spruce, cut and glued in place. Each joint was reinforced with small plywood gussets. There were thousands of them. Our house was full of the aroma of glue, and drying ribs were stacked on top of cupboards and in out-of-the way places around the house.
During the winter, our working time was drastically curtailed as the garage had to be laboriously heated with the aid of a pot-bellied stove which John would coax into life. The stove was invariably glowing red-hot before the temperature rose high enough for us to work on the biplane.
The juggernaut of Tornado Flight Testing continued…..
In my work as an aeronautical engineer I had considered it an essential part of the task to fly in many aircraft as possible in order to broaden my experience. Having knowledge of how the various systems worked, and how the aircraft behaved, was a vital step in turning theory into practice. This was of prime importance when dealing with the interaction of man and machine. In the century since man first succeeded to design a workable flying machine, flaws have still slipped past the checks in any design organization, simply because of the complexity of the machines and the emerging technologies that have been utilized. Flight testing was the last link in a long chain, and it was there that the responsibility for the final product rested.
During Tornado design, much effort was spent in perfecting the variable-sweep wings which would give good low-speed handling coupled with lower supersonic drag when swept, coupled with the promise of a smoother ride in gusty conditions at low level.
Would it work?
Once in flight test the aircraft lived up to its promise. It was gratifying to find that the advantage of variable geometry was borne out in a positive way when the Hunter flying chase on the Tornado on a low-level trip through the Lakeland hills had to pull up out of formation. Back on the ground at debriefing, chase pilot Alan Loved drily remarked that he thought it was time to quit when his helmet started bounced off the Hunter’s canopy in the turbulence. Meanwhile the Tornado, wings swept fully back and steaming down the valley, was flying as if on rails and was completely unaffected by the gusts.
Inevitably there were smaller problems. We fitted vortex generators on the vertical to cure lack of rudder control power. A slight oscillation in pitch at transonic speeds was traced to a minor flow separation around the back end of the fuselage. Various shapes were constructed in wood and fiberglass, the fuselage back end of P02 was re-contoured with body filler, and eventually the problem was resolved after much burning of the midnight oil.
Another problem centered around the thrust reversers. Needed to give the aircraft good short-field performance, the reversers on occasion would cause directional instability on the runway during the landing run. Around the same time Saab in Sweden had the same problem on their Viggen fighter. We had a couple of unplanned excursions on the runway, one during a rainstorm.
In the case of the Tornado the behavior was traced to an un-predicted flow attachment along the vertical tail when the reverser buckets were actuated. This gave a side force on the vertical tail. The reverser buckets were modified and the nosewheel steering modified before the problem was eliminated.
By 1976 the Tornado prototypes were flown down to appear at the Farnborough air show for the first time. It was an education to see behind the scenes at this week-long display. Our aircraft were maneuverable, but seeing for the first time the brightly colored F-15 and YF 17 darting about the sky was a revelation. They were extremely impressive.
We had an incident on P08 during testing of a retractable laser tracker in which the turbulence from the laser under the nose as it extended unlatched one of the large panels covering the avionics on the right side of the nose. The panel swung up and smashed the canopy, knocking out pilot Tim Ferguson, then the debris went down the right hand inlet, wrecking the engine. In the control room we lost our communications with the crew, and much of the instrumentation. However pilot John Cockburn in the rear seat of P08 managed to keep the damaged aircraft flying until Ferguson came round. With the aid of our Lightning chase pilot, Pete Ginger, who was in loose formation only yards away when it happened, P08 was gently flown back to the field and landed. The right engine of the jet was demolished. In addition to the canopy damage, the cockpit was trashed and there were hundreds of gashes all over the airframe. It took three months to repair the damage.
The laser was repackaged to fit into a fixed fairing and so equipped the Tornado later went into service during the Gulf War.
One side-note to this. The mission had originally been a simple navigation mission, and I had briefed Navigator John Gray the night before. However, a last-minute engineering change required the extension and retraction of this laser to be added to the Flight schedule. Chief Test Pilot Paul Millett had made me change the crew composition to include a pilot in the rear seat because of this change to the flight cards.So John Gray lost his ride, and John Cockburn did sterling work in recovering the aircraft.

Later (15 April 1980)in Germany Tornado prototype P04 from the Manching Test Base was lost while practicing for the Hanover Air Show, killing pilot Ludwig Obermeier and Navigator Kurt Schreiber.
We had two Buccaneers which were based at Warton for the development of the Tornado avionics, having a modified rear cockpit with the CRPMD and the ground mapping and terrain following radars.
In 1978 Buccaneer XT 285 crashed on the range at West Freugh in Scotland, during a Test mission. Pilot Alan Love and navigator Roy Bigland were killed. I had worked with them at Warton and in Germany.
Also, closer to home as far as I was concerned, although I had moved on by that time, P08 crashed into the Irish Sea on June 12th 1979, killing Pilot Russ Pengelly and ironically…RAF Navigator John Gray…who had just missed being involved in the previous incident in the same aircraft.
Now that the Tornado flight testing was tapering off, and the Jet Provost/Strikemaster production was winding down, I transferred into the Advanced Projects Department. It was a quieter, more ordered way of life than the constant alarms and excursions of a busy flight test program, I found it more creative and just as challenging, with my job now to be constantly improving on the existing generation of aircraft, and striving to beat the competition.
I had always tried to instill my enthusiasm for flying into others, whether this meant giving a beginner a quiet circuit of the local area, or a session of aerobatics at a safe height for those who wanted something different. Starting at college and later, working in the aircraft industry, I took my colleagues flying. At one stage when we were working with partner countries on international projects I could be found flying the Chipmunk with one of the engineers from a partner European company in the rear cockpit. I think it helped improve aeronautical relations. It was also undeniably great fun.
Private flying in England was expensive, but after the mid-seventies, with fuel costs rising, and a growing family, I found that the additional imposition of extortionate navigation charges and landing fees made cross-country flying prohibitively expensive. The final straw came when I had to fly from Blackpool back to Liverpool one day, a matter of some thirty miles in a straight line, or a drive of fifty miles, only to find that the landing charges for the trip exceeded the cost of hiring the aircraft. Trying to keep current enough to be able to fly instruments in the perennial murk of the English winter was another problem, and I eventually settled for flying only in good weather and letting my instrument rating lapse.
Tragedy struck again even in the world of small aircraft. Rod Turner, with whom I had flown the Chipmunk many times, spun into the ground only a few miles from Blackpool. Then Jane Murdoch was lost in an Aztec over the North Sea one winter’s night. More good friends gone.
By this time I was immersed in the world of aircraft design as a member of the team defining the next generation of aircraft to follow the Tornado. Out of the many strange shapes that emerged from Advanced Projects during this time was a delta-winged fighter with unconventional canard foreplanes, a configuration which was to re-emerge in the EAP and EFA fighters which emerged from Warton in the eighties, and evolved into the Eurofighter which is now in service. It was fascinating having designed these various concepts to pit the various fighters against each other on the computer and to fly them in the simulator.
Things seemed fairly settled when my world was turned upside down.
Out of the blue I had an offer of a position in the aerospace industry in California. This was a one-year contract to work on a variant of the F/A-18 Hornet, whose predecessor, the YF-17 had awed me at Farnborough. I had to decide quickly and had a few sleepless nights until I decided on my course of action. It was a very big step to make, and very much a leap in the dark. With a family to consider, and a half-built aircraft, it was not a clear-cut decision. However I decided that the only thing to do was to sell my share in the biplane, bite the bullet…and set off for the New World.

1 comment:

Maryvonne Gray said...

Hi David
I discovered your blog while googling my dad. My name is Maryvonne Gray, I am John Gray's daughter. I was wondering if you had any other memories of my dad you could share - I'm not sure how well you knew him but any impressions you can recall would be precious to me now.
Regards, Maryvonne