Trials and Errors

by Mike Brooke

  Despite being a ‘taildragger’10 the view ahead was not too restricted by the big round motor just in front of us and I found that the Beaver could be manoeuvred and steered in the desired direction without too much effort. After the typical engine run-up and pre-take-off checks we lined up on the grass and I opened the throttle progressively while keeping straight with deft jabs on the rudder pedals. After raising the tail, which happened readily, the Beaver rose in the air in a very stately manner; there was obviously plenty of lift being generated by that long, high wing. To be honest I cannot remember much detail of the next seventy-five minutes in the Beaver and my report has been lost in the many house moves since! But I do remember that there was one unhealthy characteristic that I uncovered. Astonishingly there was no discernable warning of the stall in the landing configuration. The transition from a normal descent at the correct speed to a stalled condition at too low a speed was marked only by the rate of descent, indicated on the appropriate dial, suddenly increasing to an alarming quantity. No buffet, no nose-drop, and no feeling that the aircraft was about to fall out of the sky; although that was what it was doing. Against the stated requirements and plain common sense this outcome was highly undesirable and should have been fixed. However, the Beaver had been doing its job for ages without crashing too many times. Moreover, the Beaver was nicely manoeuvrable and steep turns with a very small radius could be flown as long as the speed was held at a safe value. But in doing that the view into the turn was limited by the leading edge of the wing above my head. Back at Middle Wallop I managed to fly some circuits and landings without disgracing myself too much.

  Overall this Pilot’s Assessment exercise was a great experience. I had flown an aeroplane that I would be very unlikely to have got my sticky hands on otherwise. I had seen at first hand how another flying service operates and I had learnt to manage a test flight that covered all the main stability, handling, performance and qualitative assessment aspects of the past nine months’ syllabus. I now felt better prepared for the ‘big one’ – the Preview – whatever flying machine might come my way.

  Note

  10 A taildragger is an aeroplane with its central, third wheel at the back end, as opposed to the more frequently found location – under the nose.

  10 A-BUCCANEERING WE WILL GO, ME LADS!

  The final walk to the Ground School came on Monday 13 October; our Indian colleagues thought this date was very inauspicious. I told them that it was fine – it wasn’t a Friday. However, it was actually very special because it was the day when we sat the last ever, final and ultimate examination of our academic knowledge. That meant that we were getting close to the end of the course and now, ever more hopefully, to graduation as test pilots and FTEs. We had handed in our penultimate reports and our next test assignment would be our last. But it was also going to be the biggest. By the concluding week of this year’s course, in early December, we would have, in teams of two or three, written what amounted to a good-sized, illustrated book on our evaluations of a current operational aircraft that we had never flown before. On top of that would be a nerve-wracking thirty-minute presentation to the great and the good from the school, test flying establishments and representatives of the operational worlds we had dared to enter. We pilots would be allowed a maximum of five hours flight time each to achieve this not inconsiderable aim. But the question now doing the rounds was, ‘Which aircraft will it be?’

  The day soon arrived when we would find out. We all assembled for the briefing on the Preview exercise and listened to all that was said, but all the time we wondered where and to what we would be headed in a few days time. Wherever it was we would be allowed a maximum of three weeks from start to finish, before we had to start burning the midnight oil to produce our reports, as ever, within ten days.

  At the end of the briefing the new CO of ETPS, Gp Capt. Mike Adams, announced the allocation of teams to aircraft and the locations where the exercises would take place. They were:

  Flt Lts Vic Lockwood and ‘Rusty’ Rastogi were to assess the McDonnell F-4 Phantom as an interceptor/fighter, at RAF Coningsby in Lincolnshire.

  Flt Lts Duncan Ross and P.K. Yadav were to assess the DH 125 Dominie as a light transport and training aircraft, at RAF Finningley in South Yorkshire.

  Flt Lt George Ellis and Lt Cdr Tom Morgenfeld were to assess the BAe Harrier in the ground-attack Short Take-Off and Vertical Landing (STOVL) role, at RAF Wittering in Lincolnshire.

  Flt Lt Chris Yeo and Maj. Svend Hjordt were to travel all the way to RAF Lossiemouth in northern Scotland to assess the BAC/SEPECAT Jaguar in the fighter-bomber role.

  Flt Lt Roger Searle, Capt. Gerard Le Breton and Herr Udo Kerkhoff were to assess the Folland Gnat as an advanced trainer at RAF Valley, on the Isle of Anglesey in North Wales.

  A big team of no less than four were allocated to assess the Westland Sea King at Royal Naval Air Service (RNAS) Culdrose in Cornwall. They were: Sqn Ldr Rob Tierney, Flt Lt Terry Creed, Capt. Bruno Bellucci and Mr Rob Humphries.

  As befitted a small helicopter only two guys were sent to RAF Ternhill, Shropshire, to assess that particular ‘whirlybird’. They were Lt Simon Thornewill and Herr Eduard Küs.

  Finally, yours truly was teamed up with Flt Lt Mark Hayler and Mr Neil Sellers to go to RAF Honington in Suffolk to assess the HS Buccaneer in the low-level strike/attack role.

  Our departure date was to be Monday 27 October, so the ten days following the Preview Briefing was taken up with reading into the Buccaneer’s Aircrew Manual, Operational Data Manual and Flight Reference Cards (FRCs or more colloquially ‘Checklist’). I also tracked down a book that gave the history of the Blackburn NA 39/Buccaneer project. Mark, Neil and I had several get-togethers in which we decided what tests we would do, in which order and who would do what. Then it was time to prepare our individual test cards, which was a bit of a lottery as we had no idea how much of our tests we would be allowed to do. Our ETPS staff ‘overseer’ for the exercise was to be Graham Bridges. I found that pleasing in the sense that I had started the course under his wide and capable wings and I would finish it in the same manner.

  There was one thing that was different for us, compared to the other teams. There were no dual-controlled Buccaneers. It was for this reason that previous attempts by ETPS to use the RAF’s Buccaneer as a Preview aircraft had come to nought.11 However, before we went to Honington, Mark and I flew a Boscombe Down Hunter T7A, which had the Buccaneer’s flight instrument panel fitted, and we each gained an Instrument Rating using that panel. That meant that we would be allowed to fly the Buccaneer, with a No. 237 Operational Conversion Unit (OCU) staff member in the back seat.

  On the evening of Sunday 26 October the Preview adventure started with us driving the long diagonal across the country from Wiltshire to Suffolk. We settled into our rooms in the Officers’ Mess and then met up in the bar to toast what we hoped would be a rewarding and successful stay. We were not late to bed as ‘tomorrow was another day’ and likely to be a very demanding one; like many of the tomorrows to come over the next three weeks.

  As with any flying training situation our first destination was the Ground School where we would be introduced to the Buccaneer’s many and varied internal organs: its electrical, hydraulic, fuel, flying control and electronic systems. These lessons would normally be given to student pilots converting to the aeroplane over a period of weeks; we had just a few days. So it came at us fast and furious in condensed packages always signed off with ‘… and you can read more in the appropriate section of the Aircrew Manual.’

  Then it was into the simulator. Within a week of arriving at Honington I had been crammed with knowledge about this rather odd naval fixed-wing bomber. I had started to become accustomed to the often-haphazard layout of the cockpit and the naval aviators’ apparent obsession with black and white magnetically operated indicators, rather than the lights and illuminated captions that I was more used to. I had also flown two further sorties in the specially instrumente
d Hunters with the poor soul who had been allocated to look after me; his name was Lt Alan Crabb, an FAA pilot who, thankfully, had lots of Buccaneer time in his logbook and plenty of experience of sitting in the back with no method of control over his students’ actions other than shouting!

  It was on the afternoon of Bonfire Night, Wednesday 5 November, that we met in the flying clothing section to gird our loins in a fit manner to commit aviation in the erstwhile Mr Blackburn’s high-speed, low-level, nuclear-capable bomber. Perhaps this is the right time to introduce this piratical attacker? The Buccaneer was conceived by the then Blackburn Aircraft Company, based at Brough in East Yorkshire, in response to Naval Staff Requirement NA 39 issued in June 1952. By July 1955 the tendering process was completed with Barry Laight’s design from Brough winning the development contract. Initially the aircraft was not named and was simply known to the public as the Blackburn NA 39. Secretly it was referred to as the Blackburn Advanced Naval Aircraft – BANA – and that soon became the ‘Banana Jet’. A soubriquet somewhat enhanced by the curvy look of the fuselage.

  The NA 39 possessed several innovative features, most notably the use of air piped from the engine compressors and ducted to blow over the wings at low speeds to delay the onset of the stall. Using this natty system, with the flaps down and the ailerons drooped, the Buccaneer could ‘come aboard’ its aircraft carrier about 30kt slower than it would have done without it. This ingenious system was correctly called Boundary Layer Control or BLC, but soon became known as ‘blow’. After a fatal accident during development flying the blow system was extended to include the tailplane and its extendable flap that preserved longitudinal trim when the wing flaps and aileron droop were fully deployed. The original Buccaneers were powered by two de Havilland Gyron Junior engines, which each produced just over 7,000lb of thrust. However, as the aircraft became operational in the early 1960s, the weight it had to carry had increased markedly and it soon became apparent that the Gyron Junior was just that – not man enough for the job.

  After a couple of in-service losses the FAA Buccaneer fleet was grounded. But the company had an answer and by late 1966 a new version was introduced that had a pair of bigger, more powerful engines: Rolls-Royce RB 168/Mk.101 Speys. They shoved out a total of nearly 25,000lb of thrust; about 40 per cent more than their predecessors. These splendid motors gave the Buccaneer a new lease of life with more range, increased payload capability and safer operation, especially during take-off and the approach and landing phases of flight. There were also changes to the airframe and operational equipment, the most noticeable of which were the enlarged intakes each side of the cockpit to suck in all the extra air demanded by the bigger engines. To make it work correctly the blow system required a minimum air pressure to go through the narrow slots in the wing leading edges and ahead of the ailerons and flaps. That, in turn, meant that the pilot had to select more throttle (thus thrust) than was needed to make the descending final approach path at the correct speed. So another unique element of the Buccaneer’s shape arose. It had a huge airbrake at the back end which, when it was fully opened on the approach, added drag to offset the surplus thrust. This design feature was achieved by a large tail cone that was split vertically and opened and closed by a hydraulic ram operated by a switch on the right-hand throttle.

  Another feature of the Buccaneer’s operation and layout that was new to all landlubbers like me were the folding wings. The hinge-line was a metre or so outboard of the main landing gear. The wing-fold was operated by hydraulic power and selected by a big guarded handle on the right-hand console in the cockpit. Of course, being a naval design, the aircraft also had a hydraulically operated hook at the back end, underneath and just ahead of the tail cone/airbrake. A hook-shaped switch in the cockpit, near the undercarriage buttons, selected this. With all this hydraulically operated stuff the company had decided to use the higher than usual operating pressure of 4,000 psi. An added bonus of this was that the wheels came up very quickly after selection; this was another highly desirable outcome for aircraft carrier operations. Once you had been unceremoniously slung off the deck by the steam catapult what you really did not want was unnecessary drag slowing you down.

  But the Buccaneer had now become a land-based, strike/attack aircraft operating with the RAF. How did that come about? In 1965 the Labour government scrapped the BAC’s TSR2, and then in early 1968 the order for its replacement, the American General Dynamics F-111K, was also cancelled. Thus the RAF was forced to cast about for a replacement that was available and affordable. They reluctantly selected the Buccaneer; the only realistic choice left to the Air Staff. The Buccaneer was seen simply as an interim solution, but delays in the Panavia Tornado programme would ensure that the ‘interim’ period would stretch out, and the Buccaneer would remain in RAF service for over two decades, long after the FAA had retired the type. With the phased withdrawal of the Royal Navy’s carrier fleet during the 1970s, FAA Buccaneers were transferred to the RAF, which had taken over the maritime strike role. From 1970, the RAF Buccaneer force re-equipped with WE 177 nuclear weapons. At peak strength Buccaneers equipped six RAF squadrons assigned to NATO for overland strike duties in support of forces opposing the Warsaw Pact, plus one squadron (No. 12) for maritime strike duties.

  After a week of technical briefings and five hours in the Buccaneer flight simulator we felt ready to start flying; we just hoped that our hosts felt the same. So I found myself climbing up the narrow ladder that led to the front cockpit of Buccaneer XV 348. Actually getting dressed to fly had been a long and arduous task. Although I had infrequently worn one before, the donning of an immersion suit over a green fluffy ‘onesie’ and anti-G trousers had proved a bit of a trial. Then there were the flying boots, lifejacket, leg restraint garters and the harness that would connect me to the ejection seat to go on over it all. The encumbrance of all this flying kit made climbing the ladder, strapping in and the pre-flight checking process much more difficult than it had been in the simulator, when I had just worn a normal flying suit, lifejacket and harness. Once I was correctly strapped in I raised the seat and found that, just for once, despite my short back-length, I could see out very well. The only snag was that I could no longer apply full rudder, even with the pedals selected all the way back towards me! Actually, my feet barely reached the cockpit floor. It was a shame, but I would have to lose a bit of that great view over the nose to be able to apply full rudder. I adjusted the seat height accordingly.

  However, given time, and a lot of patience from Mr Crabb in the back, I eventually got the checks all done and the engines going. Unlike all the aircraft I had flown before, the Buccaneer did not have a self-contained engine starting system. A large, low profile trolley was rolled up and a flexible hose was plugged in to the side of our flying machine. This apparatus was known as a Palouste, named after the little French jet engine inside the trolley.

  When all the switches and levers had been arranged correctly a wind-up signal was given to the ground crew and they opened the throttle at their end. The wee turbine wound itself up, the slack hose went rigid with the air pressure and one of the mighty Speys started to turn. All I had to do was give it some fuel and off it would go. When the engine was pushing out more air than the Palouste the latter gave up the battle until I selected the second engine. Then it bravely did the whole thing again. Once that and the electrical ground power unit had been disconnected we only had to complete a long list of functional checks of all the moving bits before we were allowed to go. So with the wings now where they should be, sticking out on each side, and the flaps and ‘droop’ set for take-off, we set off towards Honington’s 9,000ft-long east–west runway.

  On the ground the Buccaneer was easy to manoeuvre and the view from the cockpit was good. The nose wheel was steered by pushing a button on the right throttle and pushing the rudder pedals in the natural sense. As befitting a large flying machine that needed to be manoeuvred quite precisely on a busy flight deck it was quite sensitive. But for
going long distances on an airfield it was a bit of a pain to have to hold the button in all the time. It became quite an inconvenience when Air Traffic Control (ATC) started asking complicated questions about our desired departure plans! Each time an answer was required the same thumb had to be used to press the transmit button on the same throttle, so leaving the nose wheel to its own devices. Nevertheless, we reached the beginning of the runway without incident and I ran the engines up, checked that all the needles were pointing at the right numbers and that there were no red lights anywhere. Brakes released and off we went.

  The Buccaneer’s large tailplane made lift-off a very easy affair and I selected the undercarriage up as soon as I sensed we were safely off the ground. The green ‘down and locked’ lights turned to red and then went out faster than I could say it. I held a shallow climb and the aircraft accelerated well. Not like a Lightning, but adequately enough. Before we reached the limiting speeds for the flap, aileron droop and tailplane flap setting I had used, I selected them up using the curious split selector on the left-hand side of the instrument panel. By checking three small gauges I could tell that we were now ‘clean’ and ready to climb. The man-in-the-back was talking well!

  The sortie proceeded along the lines of the traditional first trip, with me doing a little ad hoc test flying when I could. We went as fast and as slow as the Buccaneer was allowed to go. Put all the things that we could down and back up again. Put out the enormous airbrake at high speed: that really worked well – it felt like my teeth had migrated into my oxygen mask! We had rolled, turned at maximum rates and generally thrown the machine about a bit. Another new thing for me to master was that the engines each had two rpm gauges, something I’d not come across before. That was because Mr Rolls and Mr Royce’s excellent Spey engine is what is called a low-bypass turbofan; the military version of which was specially tailored for the Buccaneer and its low-level role. Inside the engine there are two concentric rotating bits. The inner is a small conventional turbojet engine with a compressor, combustion chambers and a turbine that drives it all around. Surrounding that is a larger, low-pressure (LP) compressor and turbine, this is the ‘fan’ bit and it produces the majority of the thrust. The design of the Spey gives it much better fuel consumption than a pure turbojet of the same total thrust – great for a low-level bomber that needs to go a good distance. I soon learnt that it was important to balance the rpms of the LP fan in preference to the inner high-pressure (HP) compressor. If the LP rpms were not balanced then the thrust from each engine wasn’t balanced either and the jet tended to fly a bit sideways.