Trials and Errors

by Mike Brooke

  Being especially interested in gathering L&D stability and control data I built those things in where I could, chattering into my voice recorder like a mad thing and making estimated measurements when I could. The notes on my test cards were a bit sparse – but that was nothing new! However, I had already noticed that the Buccaneer was not over-endowed with directional stability. It was easy to generate sideslip and at high speeds the machine continued to fly askew with the alacrity of a hovercraft. Judicious use of the rudder trim could correct this, but any significant input of aileron to roll the aeroplane at those high speeds generated an inordinate amount of sideslip; later I would find the same characteristic at low speeds when the BLC was active. At the higher speeds this could lead to weapon delivery inaccuracies as well as potential structural overstress of the fin and rudder. While doing these tests I remembered that I had read that the NA 39’s original design had a fin that was a foot or more higher. Unfortunately that height was such that the aeroplane wouldn’t fit in the aircraft carrier hangars below decks; so, like a Springer Spaniel’s tail, it had to be docked.

  By the time that we started to head back to Honington I had obtained a favourable overall impression of Mr Blackburn’s naval bomber. It was a bit like a slick Canberra with powered controls. In fact the mechanical characteristics of the control column were exemplary. The stick was mounted in an unusual way for a fast jet. The handgrip, with its usual trim switch and weapons selector buttons, was fixed vertically to a steel tube that passed horizontally into the lower part of the instrument panel. Its movements were so smooth and with so little friction I thought that it must be mounted on glass bearings. In fact I learnt later that the tube moved over ceramic wheels.

  Now all I had to do was to land this machine. The recommended method had been handed down from the Navy and I had one of its best practitioners in the back. It was going to be a bit like landing the Lightning: fly the approach until you meet the ground. No attempt at raising the nose or taking power off to smooth it out. The unbelievably sturdy undercarriage legs would absorb the impact (it says here). So we joined the circuit with enough time left to do a couple of touchdowns.

  It was while getting the aircraft set up for landing that things got busy and that the rather haphazard layout of the cockpit made itself felt. The flap/aileron droop/tailplane flap settings had to be progressively selected and closely monitored. A warning in the Aircrew Manual had stated that any significant split could lead to a loss of control. The flaps and droops were selected, usually together, in stages and these were identified by the degrees of deflection of each surface. There were three normal settings: 15/10/10, 30/20/20 and 45/25/25 and as each moved the little yellow arcs on the indicators had to be watched. Perhaps unsurprisingly these indicators were known as ‘cheeses’. Another action required was to change hands on the stick so that the right hand could be used to pull up a lever on the right lower panel. This was the aileron gear change and it allowed the ailerons to move further at lower speeds, so retaining plenty of roll authority during the approach and landing stages of flight. It was important that this lever was down for higher speed flight as the use of the full ‘low-speed’ aileron might lead to structural overstress. In fact, at very high speeds pilots were instructed to make sure that they only deflected the stick laterally over half its travel, again to retain structural integrity. I thought that was a very big ask during high-speed, low-level terrain-following or enemy aircraft avoidance manoeuvres. Whilst I was holding the stick with my left hand to do the aileron gear change (it must be an automatic box as I didn’t have to use the clutch!) I then had to move my right hand up to a small panel below the right windscreen to change the settings on the auto-stabilisers from ‘high-speed’ to ‘low-speed’.

  Once beyond the first flap and droop setting, that is 15/10/10, the wings needed to be blown, so I had to make sure that the pressures in the BLC system were satisfactory. There were two large gauges on the top of the instrument panel for the wings. However, the tailplane BLC gauge, being a later addition, had been put on the left-hand cockpit wall. That meant that I had to lift my left elbow, while retaining my grip of the throttles, and peer down into the gloom inside the cockpit under my left armpit. By now the speed was below the limit for selecting the next flap and droop setting of 30/20/20, watching those ‘cheeses’ again, and then dropping the wheels. Three green lights appeared rapidly and by now we were approaching the end of the downwind leg. The turn onto the final approach began with the final selection of flap and droop (45/25/25), pulling on the sliding switch on the left throttle to extend the huge airbrake on the stern-end, adjusting the throttles to give sufficient power to keep the BLC pressure up as well as putting the aeroplane on the correct approach angle of 3°. Gosh this was a busy business!

  Although the man-in-the-back had calculated a minimum safe approach and landing speed for the weight of the aircraft, the approach was flown using a small gauge right in my field of view when looking ahead. The gauge represented the AOA, that is the angle between the airflow and a datum line on the aircraft, usually a line that bisects the wing from front to back. As well as driving the needle on the gauge the sensor on the side of the Buccaneer’s nose fed its signals to an electronic noise generator, which gave an audio signal on the intercom, so that both crew could hear it. The noise generator system was set so that at the correct AOA, which was 20 units, a steady note was heard. If the angle was too small, that is the speed too high, a higher pitched, interrupted ‘beeping’ happened; if the AOA was too large, thus speed too low, a low-pitch beep came out. This latter sound got louder and lower pitched the larger the angle became. In this case, which was dangerous, there was a real need to get the pilot’s attention because it was possible that a large rate of descent would build up and a crash ensue. As one of the instructors, the irrepressible Flt Lt Bruce Chappel, put it so succinctly, ‘Ignore that noise at your peril or you could very quickly end up with Suffolk around your armpits!’

  Once lined up with the runway, using the red and white lights at the side of the runway touchdown area to show the correct glidepath angle, it was simply a case of holding the AOA at 20, the noise in my headset steady, and doing nothing else until the wheels hit the runway. I imagined that it was going to be a bit similar to a parachute landing – whatever you do, don’t flinch! There has long been an argument, especially among flying instructors, as to which control does exactly what when flying an approach. Does the throttle control the speed, as it does in normal level flight, while the stick points the aircraft to where it is going to land and so controls the angle of approach? Or does the stick control the AOA and thus the speed, while the throttles control, through the thrust of the engines, the rate at which the aircraft is descending and so the flightpath? Well, the answer, like in many things in aviation, is – it all depends.

  In the case of the approach to landing in the Buccaneer, flying well behind what is known as the drag curve, it was easy to discern that the stick directly and rapidly affected the AOA and, thus, speed while the throttles had a slightly slower, but no less discernible, effect on the approach angle. However, it soon became apparent that things would be a whole lot easier if I could reduce both the frequency and amplitude of my left- and right-hand inputs on the controls. Unfortunately there was a strong westerly wind and quite a lot of turbulence so ‘smooth’ was not an option. One thing that I noticed straight away was that when I pushed the throttles forward the nose of the jet went down, so I had to pull back a little on the stick. When I reduced the power then I had to lower the nose. This bizarre behaviour led me to imagine that there was a fixed length cord from my left hand to my right hand, passing around my neck, so that movement of one begat the equal and opposite movement of the other.

  By now, of course, the ground was rushing up towards my sturdy steed and me. We were doing about 130kt and Honington’s 9,000ft-long runway was stretched invitingly ahead. I just held everything steady and waited. The steady middle C noise continued and then t
here was a thump as the wheels impacted terra firma. I whacked the throttles shut and used the stick to hold the nose up; this would help us slow down before using the brakes. At about 100kt I lowered the nose and started to apply the brakes with the foot pedals on the rudder bar. As we slowed down further I pressed the nose wheel steering button to keep straight and in readiness for turning off the runway. Once I had done so we stopped while we carried out all the after landing checks, which included another new experience: folding the wings. I taxied back with mixed feelings. I had successfully flown an in-service, relatively modern operational jet and would do so again, but I also had a pile of data to sift, prioritise and discuss with my team.

  We met up that evening to analyse what we had got so far from our first flights. The cockpit assessment was essentially complete, including a ‘night lighting’ assessment done one evening in a darkened area; we were not going to be allowed to fly the beast at night. Neil had already collected a lot of information for his engineering systems evaluation. I had some, if not all, of the L&D data, as well as a few performance numbers, and Mark had gathered a good amount of his longitudinal stability and control data. We had started but still had a long way to go. I was due to fly again on the following morning and Mark was scheduled for his second sortie in the afternoon. So, after a very quick drink, it was off to our rooms to prepare our test cards.

  My trip the next day was with another naval aviator, but this time not a pilot but an observer, FAA-speak for navigator; however, the accepted naval nomenclature was ‘looker’. The brave Lt Beddoes and I boarded our Buccaneer, XV 388, and he waited patiently while I ploughed through the checks, got the engines going and taxied out to runway 09. This time I had been able to dictate more of the flight profile to suit my tests, so we set off, via the appropriate departure procedure, to start at around 30,000ft over the North Sea and about 30 miles off the East Anglian coast. But we hadn’t been airborne for long before I noticed that one of the many fuel tanks that lay along the top of the fuselage, above the bomb bay, was not decreasing. Because of the arrangement of those fuel tanks it was important that they fed evenly, otherwise the CG could possibly go outside the limits and that might endanger our safety. We declared a minor emergency and set off home, while carrying out what remedial action was possible. Forty minutes after taking off we were back on the ground with very few lines of my test cards completed. I hoped that Mark would have better luck in the afternoon.

  Indeed he did. But he was not airborne until somewhat later than planned. The effect was that he might not achieve the full time allowed, as he had to be back on the ground before the official start of night flying, at ‘Civil Twilight’, usually taken to be thirty minutes after sunset. We had agreed that one of the assessments we should make would be an arrested landing, using the arrestor cables12 installed about 400m from each end of the runway. These were there for use by hook-equipped aircraft with certain types of emergency. The request had met with the approval of management so Mark had volunteered to do it and I decided that I would go to the control tower to watch the event.

  I duly arrived to discover that Mark was on his way back and I settled into a spare chair in the glass box on the third floor of the tower, universally known as ‘Local’. The aforementioned Bruce Chappel was there, acting as the OCU’s Duty Instructor. We chatted about mutual memories and mates from our Canberra days while we waited for Mark’s callsign to come out of the ether. We didn’t have long to wait. But no sooner had Mark’s aircraft appeared overhead than the Approach Controller, in his darkened room downstairs, called up to say that he had an OCU aircraft with a hydraulic emergency coming back to make an arrested landing using the cable. I had told Bruce that Mark was also hoping to end his trip with a cable engagement, but it now looked like he had been beaten to it. Mark was asked to hold in the overhead; in fact he declined this kind offer and went off to do another radar-directed approach.

  Meanwhile the pilot with the hydraulic system fault was making his own approach. Bruce had briefly disappeared downstairs to cross-check that the rookie crew had done all the right corrective action in the right order and had four green lights in the cockpit – three for the landing gear and one for the hook – ‘down and locked’. By the time he had scooted back up the stairs the object of his attention was appearing out of the steadily lowering light of a November dusk. I watched with interest because I had never before seen an arrested landing on an airfield. The landing looked normal with the exception of a trail of sparks emanating from below the stern of the Buccaneer, where the hook was in contact with the concrete. Then there was a marked deceleration as the hook picked up the wire. But it was nowhere near that of the ‘trapped’ landings I had seen on HMS Ark Royal a couple of months earlier. In fact I was really surprised just how far the cable allowed the jet to go. Bruce, who had seen and probably done many more of these events than I, suddenly leaned over the local controller’s shoulder, took the microphone and said, ‘It’s OK, sir, we’ve got you. You can throttle back now.’ The tension of the emergency on one of the student crew’s early trips together had led the pilot, who was actually quite senior in rank, to having been so relieved as to have picked up the arrestor wire that he had forgotten to close the throttles!

  On the following day I flew once more and Mark flew his third and final sortie. At last we were making progress. My sortie, which I flew with RAF navigator Flt Lt Vaughan Morriss, was memorable for only one reason. When we returned to Honington the wind had swung round to the north and was blowing so hard that it was nearing the Buccaneer’s crosswind limit. From messages passed to us I gathered that the high-priced help were worrying about this relatively unknown and inexperienced person in charge of one of their precious aeroplanes. Even worse, it was someone who had not really received all the normal gamut of training. Of course, when you realise others are worrying about you it does beg the question, ‘Should I be worried?’ I looked at the situation philosophically. Over the thirteen years that I had been flying I had done a lot of crosswind landings (something that naval aviators don’t often get to do!) and if I couldn’t get this machine down safely then I would go to an airfield that had a runway more aligned with the wind.

  We arrived in the circuit and I flew the pattern as well as I could. It was a right-hand turn onto the final approach on Runway 09, so the wind was making life even more difficult by pushing me into the turn towards the final approach line. By now I had got accustomed to the synchronisation of left and right hands to achieve a satisfactory approach angle and hold the AOA correct. Apart from a bit of turbulence and an adjustment to avoid the wind blowing us through the final approach line it all went much as usual. I set up a drift angle and watched the runway through the left-hand quarter panel of the windscreen. As we came over the runway I prepared myself to prod the rudder to straighten up just before the wheels impacted the runway. About … NOW! I thought and, as the aircraft very obediently responded, to my surprise the nose came up a little: I just held the attitude and power. The wheels just kissed the runway. It was like one of my better Canberra landings. I closed the throttles and immediately lowered the nose wheel onto the ground so that I could keep straight more easily in this sideways gale. I was quietly congratulating myself when there was a gruff censure with a Scottish accent from the back seat: ‘That’s no way tae land a Buccaneerrrrr, laddie!’ He obviously preferred the teeth-jarring naval arrival!

  Team conferences in the Officers’ Mess bar and my room followed and we now found ourselves in a position to do some mopping up of some of the data points and qualitative assessments that we were still a bit short on. My final sortie was not programmed until the following Tuesday, so we decided that we go home for the weekend and travel back on the Monday.

  The weather in East Anglia during November can be dire. Low cloud, cold easterly winds, fog off the North Sea and poor visibility are all typical. When we returned to Honington that is exactly what we found. As the local management would not recognise my instrument
rating I was getting nowhere fast with completing that final trip. After four days, and with not a glimmer of hope for decent weather over the horizon, I contacted Graham Bridges at Boscombe Down and asked his permission to return to base and perhaps fly the final sortie in one of A Squadron’s machines. After a suitable time lapse for negotiations he came back with a response: ‘Pack yer bags, lads and come home.’

  Monday 17 November dawned bright but breezy, in fact downright windy. It was the day scheduled for my final Preview Exercise sortie. The aircraft was to be Buccaneer S2 XV 337, allocated to A Squadron. The short straw for back-seat occupant had been drawn by Flt Lt John Kershaw; an ex-FAA pilot who had transferred to navigational duties with the RAF. I was in safe hands – I just hoped that he felt the same! We planned a trip of about one hour to cover some of the outstanding items of our overall flight test programme. This included some single-engine handling and a brief spell of low flying in Wales to assess low-level flying, handling and gust response. The day was near perfect for the latter, but with northerly winds of 25–35 knots.