by Mike Brooke
‘Do you think that it is operationally viable to expose the delivering aircraft to the concentrated enemy firepower that it will undoubtedly encounter over a Warsaw Pact airfield?’ I asked. I remembered asking the same sort of question when my 1960s low-level strike/attack squadron changed from a stand-off nuclear weapon delivery system called LABS to an attack profile that required us to fly low and fast right across those same Warsaw Pact airfields.19
The answer was at best indirect, at worst woolly. However, someone there reported me back to management because I was later called to appear before the Wing Commander who, with a wry smile, told me that I was to confine my thoughts as to how to test things and leave the operational thinking to the folks who were paid to do that. I think that he realised that my motives were pure but that he was constrained by direction from much higher up.
Notwithstanding the ‘rocket’ I received, JP 233 provided us, the boffins, ground crews and the aircrew at West Freugh with hours of endless fun. The prototype munitions had first to be tested, their effects quantified and the optimum speed and height for delivery determined. To do this the boffins came up with the Four Tube Rig (FTR). This was, as its name prosaically suggests, a container with four tubes, arranged in a square that would be the launcher for four of the catering bomblets. It was decided that one of these boxes would be put into the Buccaneer’s rotating bomb bay, with all the firing electrics connected to a panel in the rear cockpit. The Hard Target had its origins from this trial and machinery went out there to reconstruct areas of representative airfield surfaces.
The problems started early in the trials process. If the sub-munition failed to leave an FTR tube but stuck halfway out then there was a danger that the now potentially live bomblet could explode in-flight and structural damage would ensue when the bomblet’s now protruding nose hit the fuselage as the bomb bay rotated closed. The big problem was that with such a small munition it was difficult for the range personnel to determine whether the bomblet had not been ejected or was a ‘dud’. The final answer was a pragmatic one. The end of each tube would be covered with a high visibility disc. If the number of explosions observed did not match the number released then the bomb bay would be left open and a slow flypast be made over the range or air traffic control towers for observers with high-powered binoculars to see whether any high-visibility discs were still showing. The final catchall was that – if in doubt land with the bomb-bay door open! Later in the trial process we had to start thinking about carriage and release of the JP 233 sub-munitions from the large pods that would represent the operational load for the Tornado (then still called MRCA). Carrying two of those monsters on a Buccaneer from a 6,000ft runway, even with the minimum fuel load, was going to be a challenge. Normally our take-offs at West Freugh were done without the use of the BLC mechanism or ‘blow’. But that option did exist and was still used at very high weights. The problem with using blow was that the take-off run was a bit longer because there was less thrust from the engines as a lot of the air that would have given the required power was being used to get more lift out of the wings. A corporate aircrew solution was proposed. We would set the flaps and droops to the usual ‘blown’ setting of 30/20/20 but turn the BLC off. At a predetermined point in the take-off run, predicated by the aircraft’s weight, headwind and temperature, the blow would be switched on. This would therefore give us the best possible performance off the 6,000ft runway at West Freugh for the higher than usual aircraft weights. The problem was that there were potential handling problems related to this technique that would need examination. Call in the company! I left the RAE Weapons Flight before this conundrum was resolved, so lost track of the outcome!
In late 1977 we received paperwork for the trials that would be required for the UK’s first Laser Guided Bomb or LGB. The whole system was known by the codename Pavespike/Paveway and had been in use on the other side of the Atlantic for some time. For instance the LGB had been very successful in cutting communications and supply links during the Vietnam War, especially over bridges. The average accuracy of the LGBs used there was 23ft as opposed to more than 400ft for unguided bombs. They had their limitations, usually caused by cloud, mist or fog obscuring the seeker’s view of the laser spot designating the target. Moreover, the actual designation method could also be an operational limitation. If the target was to be illuminated from the ground then that meant having personnel close by and good ground-air communications. If the target was to be illuminated from the air, either by a third-party or using a self-designation system, then vulnerability to anti-aircraft defences became an issue, especially as the ideal delivery was to be made from medium altitude.
In its early form the UK LGB was a standard-issue 1,000lb bomb with bits strapped to it that allowed it to seek and track a laser and then move four fins at the rear end to make the bomb fly to the point of laser light reflecting from the target. Our job would be to first carry the weapon and ensure that it did not cause any untoward handling difficulties and then release it. The first drop would be a totally inert, ballistic drop with no attempt at guidance, the second drop would have a pre-programmed flight guidance protocol to check the ability of the fins to steer the bomb and the third delivery a drop onto a laser-illuminated target to see if the bomb would actually do what it said on the label. Further developments of delivery profiles and envelope expansion would come later.
On Wednesday 8 February 1978 Pete Hill, who had replaced Ian Hail, and I strapped into Buccaneer XW 988 at Farnborough to fly to West Freugh for the first UK LGB trials. Ian ‘Jack’ Frost was the other test pilot involved and he took the low road to Bonnie Scotland in a Devon of Farnborough’s Transport Flight. On the following day two Buccaneers were out on the line waiting for us to get aboard and do the business. The distinctive shape of an LGB was hanging menacingly from the starboard inner pylon of Ian’s aircraft. My job that day was to fly ‘chase’, that is to fly in formation with Jack, film the bomb release using the two movie cameras on the port wingtip pylon and, they said, ‘Chase the bomb down as far as you feel it is safe to go’! I’d never flown formation on a bomb before!
I had noticed that the two aircraft were not parked in line next to each other, as might usually be the case. This odd arrangement was soon explained when I was asked to get into the cockpit half an hour before we were due to man-up and close the cockpit canopy. On the left-hand side was a neat rectangle marked out in black grease pencil. This represented the field of view of the wingtip cameras and was there to help me position my aircraft for the best air-to-air coverage of the morning’s historic event.
About thirty minutes before we were due to get airborne the four of us, Jack and his nav and me and Pete Hill, walked out together. We didn’t often get the chance for formation flying in this business, unlike American test pilots whose philosophy seems to be to chase absolutely everything. But flying close together is like riding a bike, once you’ve got the hang of it the basic skills never leave you. Nevertheless, when you haven’t done it for a while there is a raised sense of awareness and a frisson of excitement. We started up together and taxied out to Runway 24. We had decided not to take off in close formation so I let my brakes off fifteen seconds after Jack had departed from just ahead of my left wing. Jack had a small amount of handling to perform just to ensure that carrying the LGB was essentially identical to carrying a normal 1,000lb bomb. Once that was done I closed up until I had 988 nicely framed in the black rectangle on my canopy. We changed radio frequency, checked in with the Luce Bay Range Controller and climbed to the drop height of 12,000ft. After flying a full pattern under radar control we turned outbound to the north-west for the ‘hot’ run. As the ten-second countdown started Pete started up the cameras and I moved out a little just to ensure that if the strange-looking bomb did anything odd I wouldn’t be in the way. At the controller’s count of ‘zero’ off it came. A clean separation and off I set to follow it down. It flew a typically normal ballistic path, slowing down only slightly but as the
angle and rate of descent increased and we passed 8,000ft I thought discretion the better part of valour and pulled up and away. I tipped the left wing down and saw the splash just short of one of the several raft-mounted targets in Luce Bay. Well, that was that. The first release of a LGB in the UK.
Of course, by definition, that was the beginning. My turn the following day was to release number 2 with its pre-programmed flight control inputs. This one had a special radar reflector so that the range could track it with the radar as well as observe it with their high-powered optical telescopes and high-speed cameras. It too behaved impeccably. Number three was released by Jack and I watched using the tripod-mounted ex-German U-boat binoculars from the air traffic control tower. This time the range illuminated the target with a laser, the bomb did what it was supposed to do and removed the laser reflector from the top of the mast on the raft. There were cheers from the scientific team but moans from management because that meant that they would have to keep replacing the rather expensive reflectors as the trials went on! In fact, I believe the question was asked as to whether the boffins could make the bomb miss!
But there was a lot more to weapons trials than just hurling the things at the ground (or sea). The total package of development included carriage and jettison as well as release. Some of these tests made us test pilots actually practise the test techniques we had learnt at ETPS – and have to report on the results! They also brought with them some challenges to our abilities to handle the Buccaneer correctly.
For instance I walked out to my colourful jet one day to find what looked like a dustbin, painted in black and white quarters, hanging on one wing. On the opposite side was an inert 1,000lb bomb. The dustbin was a special store designed to fit on a bomb station in tandem with another more conventionally shaped bomb. My job was to fly this thing around to find out how fast we could go before its drag became too much of a control problem, and to take notes of the fuel flow for performance data. The prediction was that the drag would become so much that I would run out of rudder trim at about 350kt. The 1,000lb bomb was there to try and balance the asymmetric weight; however, the bomb was actually twice the weight of the ‘dustbin’. We got airborne and flew round the range areas at incrementally increasing speeds. When we got to 350kt indicated airspeed, far from running out of trim, everything was neutral! So much for the theory!
Every now and then we were allowed to use the full airworthiness envelope of the Buccaneer, as opposed to the in-service limits. In effect this allowed us to fly at a maximum indicated airspeed of 610kt, instead of the service maximum of 580kt. Although only 30kt more one soon found out why it had been set there for everyday use. I did my first low-level excursion at that speed over Loch Ryan and Luce Bay. In addition to an even greater increase in the cockpit noise level, I noticed that there was a definite tendency for the aircraft to go out of balance directionally and, following the advice in the Aircrew Manual, I used judicious inputs of rudder trim to make sure that the tail kept following the nose exactly. It wasn’t easy and then at the bottom end of Luce Bay I started a right turn. That was to fly around the Mull of Galloway and then head towards the plum duff pudding shape of the island of Ailsa Craig, ready for the next run. As I rolled gently into the turn the nose just kept going straight on and, along with the hairs rising on the back of my neck, a loud noise added to the cacophony already prevalent in the cockpit. I pushed gently on the right rudder pedal and things came back to normal; it took a bit longer for the hairs on the back of my neck to do so!
Quite often the first step for some new weapon that the boffins were researching was the aerodynamic and structural properties of their latest shape. So strain gauges were fitted and we went off gathering the data. We always started in the middle of the flight envelope as defined by wind tunnel or computer-derived fluid dynamics calculations. Not the most exciting test flying admittedly but every now and then something would get one’s attention, such as the day I was asked to do a series of test points on an experimental external store. One of the points was a 3G-force while rolling at about 30° per second at 10,000ft and 300kt indicated airspeed. I thought that this would be right on the edge of the Buccaneer’s own flight envelope so I approached this test carefully. Sure enough as I made my first attempt the nose pitched up and the roll-rate increased beyond what I had demanded. It was the beginning of a departure from controlled flight. I moved the stick forward but it kept rising. I then remembered a bit of advice that Don Headley had given me.
‘If you ever get the nose coming up on you, move the stick forward and hit the trim switch in the same sense.’
I did that and the aircraft recovered. Jim Boyd, in the back, was very pleased when I said that we were not going to repeat that particular test point!
Another demand that needed some thinking about were the tests for negative G. Zero was easy – a parabolic pushover from a climb would do it; it also worked for –1G. But more (or should it be less?) than that was trickier. It meant doing an inverted turn and if the boffins wanted more than a few seconds of it, that was fairly uncomfortable. It also usually meant that the cockpit filled with all the detritus that had built up in the bottom!
Sometimes it was speed that was wanted, usually for drag purposes, but on one occasion a new experimental frangible nose cone for an in-service rocket pod, called SNEB, needed to be hot-soaked by flying it at 600kt for twenty minutes. This coincided with the return of one of the Buccs to West Freugh. It was an interesting flight and we set a new Farnborough to West Freugh record transit time! We had to fly as low as we could to get the maximum thermal effect. I decided that 1,500ft would do the job. Any lower than that could mean the mother of all bird strikes!
Another feature of working at ‘the Froo’ was the daily closure of the airfield for one hour at lunchtime. Coupled with the often very slow appearance of our steed from the hangar, not helped by the insistence of the folk to do everything in duplicate, we often had to get airborne with just enough time to make a couple of runs on the range before ATC shut down for lunch! Then we were still overweight for landing, especially when there was a crosswind (which was most of the time!). The Buccaneer does have a fuel dumping facility but that would take time and stop the nice folk in ATC and Fire Section from getting their midday repast. So a much better idea than polluting the area with kerosene was to use it up in the normal way by passing it through the engines.
So, when the weather was suitable we used to call the nice people who controlled the UK Low Flying System and book ourselves into the Scottish bits. Then it was down to 250ft above ground and speed at 420kt and giving the man-in-the-back some ad hoc navigation to do. I flew this way over most of the Highlands and Islands marvelling at such sights as the seaside distilleries on Islay, the columns of Fingal’s Cave and once, flying low over the Isle of Skye, passing between a tall needle of rock and the mountainside it was rooted on. One sparkling blue winter’s day we were flying along the Great Glen, there was a good covering of snow on the mountains, the visibility was unlimited and barely no wind to ruffle the surface of the lochs. It was beautiful and lifted one’s soul. It was then that a thought that had knocked on the door of my mind actually entered, made itself at home and has stayed with me ever since: It’s amazing! And I get paid for doing this!
It was during the LGB trials that something occurred that would bother me for the rest of my time in the test flying business. At one point we had four Buccaneers at West Freugh, all doing overlapping bits of the Pavespike project. The company’s aircraft, with dear old Don Headley and Nick, were doing tests to look at the carriage of multiple LGBs, our two machines were doing the release and guidance tests and then a Boscombe Down crew turned up in one of their Buccaneers to look into the handling aspects. It struck me that this compartmentalisation of roles was causing expensive duplication. We were all qualified test pilots and it could have been much more cost-effective if Weapons Flight had been given the whole package to test and report on. It wouldn’t be the first time
that I felt the need for someone to rationalise the whole test and evaluation process. But at this stage I was still a ‘Junior Joe’ and, as I had been reminded earlier, I should get on and do my job and let those who are paid to do so resolve these higher issues!
Note
19 See Chapter 29 of A Bucket of Sunshine by this author, The History Press, 2012.
15 NOT ONLY OWLS FLY LOW
AT NIGHT
A large area of R&D interest at the time was involved with giving strike/attack aircraft the capability to fly safely at 250ft above the ground in the dark. One way to do this was to use Terrain-Following Radar; this equipment had been developed for the MRCA and would be refined for operational use by the RAF’s Tornado force once it was in service. The problem with the use of any radar device is that it sends out electromagnetic waves ahead of the aircraft, which can be detected by any suitable receiver and so give notice of its imminent arrival – very useful knowledge to the opposition. Thus Terrain-Following or Terrain-Avoidance Radar is known as an ‘active’ system. What the operational ivory towers were looking for was something ‘passive’ that could not be so easily detected.
Seeing in the dark, as if it were daytime, is the province of inter alia the owl and the feline members of the animal kingdom. We humans can adapt to darkness, but imperfectly. I had found that I could fly as low as 250ft at night in my Canberra over north Germany if there was a full moon and little or no cloud, especially if there was a covering of snow. But it was risky because slender masts and dark, tree-covered up-slopes were difficult to discern. What we needed were better eyes.
