Test Flying In The Golden Age

When I joined Rolls Royce there was ample opportunity to fly a variety of flying test bed aircraft for developing the last of the piston engines plus the new turbojets such as the Derwent and Nene, In those days the salary of test pilots was augmented by a bonus for every hour flown. Consequently at times there was a tendency to favour the larger aircraft such as the Lancastrian test beds, which had a greater endurance than the Spitfire. Wyvern and Meteor.

My early days were not lacking in incidents. As the new boy ina team of five test pilots under Capt R. T. Shepherd, I began to learn my trade the hard way by testing the Eagle in the Wyvem naval fighter. This 24-cylinder piston engine produced well over 4,000 hp and was fitted with contra-rotating propellers. It was delightfully smooth when running normally, but unfortunately for me there were two separate occasions when it failed. In the first inc dent, there was a total loss of coolant and in the second there was a complete engine break-up.

I was used to four engines in the splendid Lancaster. It therefore came as a surprise to say the least when, less than a year into my chosen career, I found myself without engine power ensconced in this heavy fighter in complete silence, contemplating my next course of action.

The RAF adage. “If you cannot take a joke you shouldn’t have joined,” did cross my mind momentarily, particularly as a Wyvern had earlier suffered an engine failure with a Westland test pilot who was killed attempting a wheels-up landing when the propellers dug into the ground and forced the engine rearwards. Suffice it to say that lowering the landing gear at 18,000ft and observing that it was securely locked down did give a small boost to me, although the advice I received over the radio from my colleagues at Hucknall, who told me to bale out, was slightly disconcerting.

Lincoln cathedral was in sight and I was well placed for the disused airfield of Skellingthorpe, where I subsequently landed in one piece, much to my delight. As I sat in the cockpit on that windswept runway I was abruptly brought back to reality by a harsh movement of the controls. The culprit was the local farmer, who was moving the ailerons violently and yelling at me to get the hell out of that airfield, or words to that effect!

It turned out that he would not allow his land to be used by the Lincoln Flying Club. When the situation had been explained and he realised that the Wyvern could not in any way be classed as a flying club aircraft, I was treated to lunch and later enjoyed shooting facilities on his land for several years.

Five months later I was in the same aircraft at 25,000ft over Derbyshire when an expensive bang and vibration from the Eagle engine indicated a much more serious failure. A repeat Performance was required if the evidence was to be analysed. It turned out that the con rods had come through the crankcase.

I pinpointed Lichfield cathedral and the adjacent RAF airfield beside the A38 road and decided to attempt a second “dead- stick” landing on the basis that I should be in practice. With the front screen covered in oil and open country below I did consider abandoning the aircraft, but as soon as I wound the canopy open I had difficulty with the locking mechanism and it immediately Slammed shut, nearly taking my fingers off in the process-plus helmet and various bits and pieces such as my knee-pad.

I selected wheels down above 15,000ft. The propellers were turning the engine with a grinding noise, but luck was with me as I touched down on fire across the airfield, missing all three runways and landing diagonally on a football pitch with a match in progress, I made my apologies later to 22 red and green shirted players who had scattered in all directions.

On coming to rest I rapidly left the cockpit, nearly breaking a leg when I slipped on the oil-covered wing. The engine fire was rapidly extinguished by the RAF team in a most professional manner; they had seen my predicament just before my arrival. My brother, a Church of England parson, was intrigued to learn of my ability to navigate by cathedrals and suggested there might be a moral somewhere.

My experiences with the Wyvern made me appreciate the benefits of multi-engined flying test bed (FTB) aircraft. These permitted a new engine to be flight tested thoroughly without jeopardising the test aircraft if it failed.

They were used to flight test a new engine over most of the operating conditions it would meet in the new aircraft it was designed to power. An engine could thus be proven over most of the flight envelope long before it actually powered prototype fighters, bombers or transports. Many types of FTB aircraft were used the Lancaster, Lancastrian, Lincoln, Meteor, Dakota, Canberra, Vulcan and VC10 were classic examples which did sterling work in flight testing the Dart, Nene, Avon, Tyne. Con-way, Spey and RB211 engines.

This was a very exciting era from the viewpoint of the test pilot. A whole new generation of turbine-powered military aircraft was being developed to replace piston-engined types and in the civil field the turboprop and jet airliners were being introduced. Thus there was great scope for flying the many new types of aircraft and engines that were being developed- and test pilots revelled in it. In a number of respects it was a golden age for test pilots because there was a large demand for their services and the ground testing of engines in altitude plants had not superseded the work of flying test beds, as has happened today.

Invariably FTB aircraft were over-powered, some by the Installation of additional engines in the fuselage. Engine test pilots became very adept at asymmetric flying and coping with unusual aircraft attitudes.

The early Avon engines installed in the Meteor airframe in 1949 gave it a power-to-weight ratio of nearly one-to-one. As a result, from the time brakes were released it could take off and climb to 40,000ft in well under three minutes.

This “wolf in sheep’s clothing” astonished many RAF pilots when in the course of a routine flight one would sometimes be joined by a standard squadron Meteor. The Avon power would be gently increased until the RAF pilot’s immaculate formation flying became merely a distant view of two jetpipes vanishing upwards as he no doubt checked to see if his Derwent power was at fault. It was a very sporty aircraft indeed!

Both types of Meteor had the same Mach number limitation, but a 100 per cent increase in thrust resulted in a no-contest situation. Clearly, any asymmetric tests on the Avon were handled with caution, otherwise one would be involved in a cartwheel aerobatic manoeuvre rarely seen at a flying display.

To test the Dart turboprop for the Viscount airliner it was initially installed in the nose of a Lancaster; a Wellington Bomber and a DC-3 Dakota transport were also used as Dart FTBs.

I remember one particularly amusing scene when we were carrying out performance work at 36,000ft in the unpressurised Dakota. Its inside not unnaturally iced up and resembled a failed igloo so that my only view of the outside world was through a two-inch opening in the side window of the cockpit.

Through this gap we observed an F-86 Sabre jet fighter with Canadian markings, the pilot looking sideways in amazement as he slowly slid past before vanishing earthwards, having stalled his aircraft in the process. An hour after landing I received a call from the OC flying at RAF Luffenham: could I please confirm a statement by one of his officers who was offering high odds to anyone willing to bet that he had encountered a “Gooney Bird”, the affectionate American term for the DC-3, at such a ridiculous altitude? All attempts at a personal side bet were of no avail as a relieved squadron commander learned that his man was not hallucinating.

We undertook a number of intensive flying programmes to build up operating experience with engines rapidly before they entered service. Examples were programmes with the Conway Vulcan and Tyne Ambassador, when we used teams of pilots to accumulate engine flight experience at rates up to 18 airframe hours a day.

These led to some incidents which were amusing in retrospect. In order to build up Tyne flight experience before the Vanguard airliner entered service with British European Airways we did some intensive flying in the Mediterranean area with Tyne engines installed in an Ambassador. On the outbound flight to Malta, our first refuelling stop was at Nice. Cruising at 30,000ft we gently outpaced a BEA Viscount, likewise bound for Nice.

This caused some consternation in the cockpit of the Viscount, whose captain was a former Ambassador driver. The passengers in the Viscount had observed this twin-engined aircraft and queried its ability to pass the modern Viscount. Relations were restored once we had explained the situation over lunch at Nice. After all, our particular Ambassador was able to turn out exactly double the power of its original piston-engined version.

For the Tyne intensive flying programme we borrowed some pilots from BEA. On one occasion two of these, both senior captains, were flying the Tyne Ambassador from Malta. As senior captains they were not accustomed to the duties of second pilots and they thus contrived to start the flight with the generators turned off. It was not long before the batteries packed up and it was a rather contrite crew which just succeeded in landing a blacked-out Ambassador in the gathering darkness of a Malta evening.

Our work included tests with helicopters and early V/STOL types. I did more than 800 hours on helicopters, including over 20 hours of single-engined flying on the twin-engined Belvedere. I also made the first engine relight tests on the version of the Wessex helicopter with a single Gazelle engine. These were fairly exciting: failure of the engine to relight meant that one was committed to an auto-rotative landing.

My V/STOL experience included piloting the Rolls Royce Flying Bedstead, which demonstrated techniques needed for stable flight on jet thrust alone, and flying the RB108 Meteor and the ShortSC1 with its five RB108 engines – four for jet lift and one for propulsion.

When aircraft designed for supersonic speeds in level flight were introduced in the later 1950s, as with the Lightning, we were allocated one of the prototypes so that Rolls Royce could continue to improve the handling and performance of the reheated Avon engine over the entire flight envelope – to Mach 2 and over 70,000 ft. We also acquired a Phantom F-4 for flight development of the reheated military Spey in the late 1960s.

However, the use of such aircraft for engine testing alone was coming to an end, partly because of the greater use of ground test facilities simulating flight conditions. The cost and availability of later aircraft such as the Jaguar and Tornado dictated that flight development of the Adour and Turbo-Union RB199 engines should be carried out in conjunction with the airframe companies. Advances in engine technology, high costs and the reduction in lead time to the first flight of a new engine/airframe combination eroded to some extent the need for flight testing by the engine manufacturer as in the past.

Personally I regretted this change for many reasons, because there is much to be learned from an in-house flight facility. But one must concede that the design skills incorporated in our engines and advanced methods of ground testing were a formidable argument against continuing the earlier system.

In the case of the RB211 engine, however, it was decided to install a test engine in a VC10 FTB. The engine represented a radical advance over previous Rolls Royce commercial turbofans and was designed to provide more than double the thrust of the Conway powering the VC10. The RB211 was developed to power the Lockheed L1011 TriStar and it was considered that a 1,000-hour intensive flying programme in the VC10 would permit the TriStar certification to go ahead with minimum interruption on the engine side.

The plan was to replace the two Conway engines on the port side of the VC10 with an RB211 and carry out initial handling trials before the first flight of the TriStar, followed by the intensive flying programme.

A squadron VC10 was hired from RAF Brize Norton and we did five hours of familiarisation flying when we assessed the aircraft’s characteristics with two of its four Conway engines at idle power. Although the test RB211 was scheduled to deliver nearly double the thrust of a single Conway, we needed to ensure that a premature shutdown of the engine would not hazard the VC1o.

In the event our first flight in March 1970 was made with the RB211 delivering only half the thrust of the engine flying today in TriStars. My report at the time said that we had an excellent flying test bed but that the RB211 engine required a fair amount of development. Unfortunately we had completed barely 100 hours of flying in the VC10 before financial problems made it necessary to transfer future flight development of the engine to the Lockheed TriStar programme some 5,000 miles away in California.

This decision coincided with the end of my test flying career, but my flying duties with the company continued until my retirement late in 1984. I became responsible for the company’s executive aircraft fleet, which at its peak consisted of two HS125s, a BAC One-Eleven, a Gulfstream II and several piston-engined aircraft.

I was fortunate in plying my trade as a test pilot in an era when the demand for pilots to test engines was much greater than it is today. In conclusion I would like to pay tribute to the entire Rolls-Royce flight-test team and the designers and development engineers with whom I worked through my 23 memorable years at the “sharp end” of testing some splendid power units.