by Mike Brooke
When I returned to Bedford I flew with Andy Digby in the Wessex whenever it was possible. He took me for my first tour of London by air and taught me how to use the Helilanes. These are air routes for helicopters that criss-cross the capital to allow access to various helipads in the city and so fly safely below all the airliners using Heathrow. After about seven hours of flying under his watchful eye, Andy declared me ready for a proper helicopter instructor to check me out. So Lt Thomas RN was wheeled out from Farnborough and he put me through my paces, including quite a few emergency drills and engine-off landings. After two sorties he declared me fit to fly the Wessex on my own – so I did.
Over the next sixteen months I would fly about fifty hours in that old Wessex; I use the term old because it was one of the very early models – a Mark 1, tail number XM 926. The Westland Wessex was a UK-licensed built version of the Sikorsky S-58 ‘Choctaw’. It was powered by a single Napier Gazelle turboshaft jet engine that developed about 1,600shp and had a payload of about 1 ton. The RRS Wessex had originally been with the Royal Navy in the anti-submarine role, but when the Wessex was upgraded to have two engines – a much safer set-up for hovering over the sea – XM 926 was acquired by MOD(PE). At the time I was flying 926 its role was in the R&D of a radar that had its aerial in one of the rotor blades. The lead company for this was Ferranti who had developed the most difficult part of the system: a very clever waveguide that could transfer the radar signal from the rotating blade down the rotor shaft, then via the signal processor onto the screens, of which there were two. One was in the cabin, for the boffins to watch and control, and another was let into the right side of the pilots’ instrument panel.
Getting the Wessex going was much like the Whirlwind, except that the engine was started by an AVPIN-powered starter turbine, just like I had used on the Canberra PR9, Hunter F6 and the Lightning. Once the rotor had been coupled to the engine then all the principles of flying a helicopter came into play. The Wessex had a tailwheel rather than the rather odd four-wheel layout of the Whirlwind, which made smooth landings easier. The extra power was very noticeable and I quickly felt at home.
The Rotor Blade Radar (RBR) trials were very interesting. The detail that can be seen on a radar screen is directly proportional to the length of the aerial. As the aerial was about 4m long then the detail that could be seen on the screen was amazing. For instance when we flew past the grass airfield at Henlow the runways could easily be picked out because the grass on them was several inches shorter. No other airborne radar of the day could have seen that. The scale on the screen could be changed from half a mile across out to over 20 miles. At the lower scale settings fences, power lines and even individual trees could be discerned.
One of the applications being researched was the use of the radar as a piloting aid for bad weather approaches to helipads in cities and on oil rigs. This led to some very interesting and absorbing flights from Bedford, down to the Thames at Greenwich and then up as far as Battersea, where we made approaches to the heliport there. There are rules about flying up and down the Thames in central London. It was to be done at about 1,000ft, or as directed by the Heathrow Radar controller, and always following the right bank. If the engine failed I had to aim to put the aircraft down as close to the right bank as possible. When the tide was out then dry land might be available but it would usually mean landing in the water. We did occasionally get clearance, for our trials purposes, to fly at or below 500ft. This meant that once we had passed Big Ben, going upstream, then I could look into the offices of the top floors of the 400ft-tall Millbank Tower; every now and then there would be pale faces looking out at me! On most of these flights I flew with my head down, using only the radar, and as we got close to Battersea heliport I would have the scale reduced so that I could make an approach right to the edge of the platform that stuck out into the river. I would look up as the radio altimeter indicated 20ft and complete the landing. Of course I always had someone in the right-hand seat to tell me if anything was going awry – it never did. This kit was a great breakthrough for poor weather helicopter flying.
The trials progressed with some amazing results for HT wire avoidance, poor weather field operations and Search and Rescue (SAR) survivor location in rough seas. But the best bit was yet to come. During a lay-up a fixed radar had been installed in the nose of XM 926. This scanned ahead of the helicopter and digital processing of its returns allowed the radar picture to become colour-coded: green for terrain ahead that was below the aircraft’s present altitude and red for any terrain above it. After initial shakedown flights we went off to North Wales to fly in the mountains to see whether we could fly through valleys safely without looking out. Indeed we could; interpretation of the picture in the cockpit was instinctive and with close monitoring from the occupant of the right-hand seat, who had the map, we were able to navigate our way successfully, at 100ft above the ground, through a lot of the most mountainous parts of the Snowdonia National Park and surrounding lumpy bits. That is until we were following a road up a hillside to get over a pass into the next valley. I was head-down when Jack Cooke in the right-hand seat warned me that we were about to go into cloud. As we were not supposed to rely on this magic kit to actually keep us out of trouble (a basic principle of experimental flying) I looked up. Sure enough the world was turning light grey as the hillside climbed into the stratus cloud. I slowed right down so that I could hover-taxi, that is fly low and slow, and try to make it over the pass following the road visually. There were no obstacles ahead, only a line of telephone posts and cables off to my left. The radar picture was showing green ahead. The visibility reduced a bit more, Jack said that it was only a few hundred yards to the top and then I noticed a car ahead of me.
Great, I thought, I’ll just follow him. I then decided to put the landing light on. This was below the nose and could be extended with a switch on the collective, so I moved it to shine at the back of the car. A few seconds later he took off like a scalded rabbit, disappearing rapidly into the mist.
Blast! I’d better turn round and go back. I gently swung round to the right and followed the hillside back into clear air below the cloud. It then struck me that maybe the driver of the car had seen the film Close Encounters of the Third Kind and when he had spotted this bright light above and behind him he wasn’t going to hang around for an explanation. So if you were the driver – I apologise!
In early 1980 I received the news that the BBC TV programme Tomorrow’s World wanted to do a piece on the RBR. This culminated on 18 and 19 March in filming sessions with presenter Michael Rodd at Bedford and then on April Fools’ Day flying to and from Battersea. From the heliport there we flew a sortie down the river and back with various cameras taped to an undercarriage leg and around the cockpit. We had three of the programme’s staff on board as well as Ferranti FTE Stu Lazenby. I did another head-down approach to Battersea Heliport and landed back on to finish the whole shoot off. Our day and a half’s work ended up as a six-minute slot on the programme later that year. That was the last flight of Wessex Mk 1 XM 926; age had overtaken this last example of the earliest of the Wessex line. Sadly the RBR never received further funding for installation in another helicopter.
Despite its huge potential and successful trials the RBR was never adopted by any helicopter operators, civil or military. It was probably too expensive. However, I found that helicopter flying is definitely fun. Whirlybirds ARE go!
Note
27 HAR stands for Helicopter Air Rescue.
27 VARIETY IS THE SPICE OF LIFE
There were a whole host of other trials to keep us busy. The Nimrod was the vehicle for the further development of the Searchwater radar that the operational Nimrods used. The drive was to develop a reliable automatic recognition system using the cross-section of any maritime target. Most of this work had been done on one of the Viscounts – more of them later. Nimrod XV 148 was the second prototype and the first one that flew with the R-R Spey engines; the first Nimrod prototype,
XV 147, had retained the original R-R Avons of the Comet airliner, from which the Nimrod had been derived. The crew of the RRS Nimrod was two pilots, one navigator, an engineer and whatever complement of radar operators and FTOs were required for the particular trial.
Still being firmly in the Cold War, one of the items on which we received a classified daily briefing were the positions of any Soviet vessels, particularly the so-called ‘trawlers’ that bristled with aerials and antennae. A lot of our equipment was at a very early stage of development and we did not want the ‘other side’ to gain knowledge of their characteristics any sooner than we could help it. On one hand this often restricted where we could fly or in which direction we could transmit. However, for building up the radar image library for the advanced version of Searchwater this intelligence helped the Viscount crew in their hunt for ‘Red Funnel’ shipping. The aircraft would try to get radar signatures and photographs as clandestinely as possible.
The two Viscounts were an unusual part of the MOD(PE) fleet, but not unique to RRS. ETPS had operated one for many years as had B Squadron at Boscombe Down. The two RRS Viscounts had come on to the books in the mid 1960s. They were both 800 Series aircraft and had interesting histories. The maritime radar research platform, XT 575, was first flown from the Vickers factory at Weybridge in Surrey on Wednesday 17 February 1961, with the maker’s construction number of 438. It then spent three years based in Austria as a commercial airliner before joining the RRE’s fleet in 1964. The other Viscount, XT 661, had constructor’s number 371 and its first flight was on Wednesday 3 September 1961. The aircraft was bought by Ghana Airways and operated in Africa until 1965 when it joined XT 575 at Pershore. By the time I arrived this Viscount was involved in various sensor trials that were highly classified and involved low-level flight by day and by night.
I only flew the Viscounts a few times, always as co-pilot, just to get a feel for the aircraft as well as the trials. It was a unique opportunity to fly this British aviation success story, the first turboprop airliner that sold in its hundreds all over the world. Flying the Viscount at low altitude was a bit of a challenge. The view from the flight deck wasn’t great and rolling the aircraft into and out of turns required a good degree of strength.
I flew the Nimrod a few times, again as co-pilot, although I had been checked out and signed up as first pilot on Farnborough’s Comet before arriving at Bedford. I had no desire to move either Geoff Manning or John Trout out of the captain’s seat. The Nimrod flew very much like the Comet, but it had much more thrust available. I don’t mind admitting that I had been quite disappointed with some handling characteristics of the Comet. It had very strong static longitudinal stability, which meant a lot of push and pull force required to change attitude and airspeed, followed by a lot of work on the trim wheel to remove the forces on the control yoke. Levelling off at 1,000ft in the circuit called for quite a lot of anticipation. On the other hand the longitudinal dynamic stability seemed quite low and this mismatch could lead to the aircraft wandering off altitude if the trim wasn’t exact. However, once you got used to it and knew what to expect the classic smoothness of Britain’s first commercial jet airliner won me over.
I remember two Nimrod events from those days. The first happened in the south-west approaches when we were flying very close to the cloudbase of a large cumulonimbus cloud. I just happened to be looking out of the window straight ahead when I saw a bolt of bright, white lightning come out of the cloud and strike the Nimrod’s nose. It is not rare to get hit by lightning, but it’s not often that you see it coming!
The second occasion was when we had to take the aeroplane to RAF Kinloss, in northern Scotland, for a second-line servicing. To do this required just four of us. Geoff was once more captain, I was co-pilot, Dickie Doherty was the navigator and John Pollock was the Air Engineer. Geoff generously let me fly the sortie and as we were handed off to Kinloss Approach from Highland Radar Geoff transmitted:
‘Kinloss Approach, good afternoon Blackbox Mike a Nimrod inbound to you, four POB (persons on board). Request a TACAN (tactical air navigation system) to ILS approach.’
We got the following response: ‘Roger Blackbox Mike, all copied but just repeat your POB.’
‘Four, sir.’
There was a long pause then: ‘Confirm aircraft type as Nimrod.’
‘That’s affirmative.’
Slowly and a bit quizzically, ‘Roger, Nimrod, four POB.’
We later found out that the No. 18 Group Flying Regulations stated that the minimum crew allowed to be on board one of their Nimrods was six. To add to Kinloss’s confusion as we passed overhead at 2,000ft we received the following call:
‘Blackbox Mike, there seems to be some discoloration on your aircraft’s tail.’
‘Yes we know, it’s red paint.’ It was part of the ‘new’ MOD(PE) colour scheme; the rest of the ‘Ripple’ was yet to come!
Being a man with getting on for 2,000 hours experience on the Canberra I flew them regularly during this tour of duty. Not many of the RRS Canberras looked like each other – or any other Canberras. A few were painted in the ‘raspberry ripple’ colour scheme and many had peculiar shaped and rather bulbous noses for housing the various radars that had come and gone over the years. I was standing beside one such, Canberra B6 XH 953, at an air show when a mother and her toddler stopped to look at it. The little lad was fascinated and said in a piping voice, ‘Look, Mummy, it’s Mister Nosey.’ He was obviously in that phase of reading all Roger Hargreaves’ ‘Mr Men’ books.
Other of our Canberras were finished in all-over silver-grey and looked fairly conventional. There was a whole host of trials of radars and other sensors going on throughout my time at RRS for which the Canberra was an ideal platform. It could fly high or low quite economically, so had good range and endurance. With one exception it had two seats in the back, so that a civilian FTO could be carried to do all the scientific work and a navigator to keep us on track. There was also lots of space in the bomb bay or the tail-cone for extra equipment and aerials.
It would be tedious to list all the work that I was involved in on the Canberras, but a few of the trials provided some interesting flying. For instance, we were involved in flying trials for two anti-shipping missile systems: Sea Skua and Sub-Harpoon. The BAC Sea Skua was being developed with Marconi Defence Systems as an air-launched, sea-skimming missile and the McDonnell Douglas Harpoon had been procured for the Royal Navy to use, primarily from attack submarines as well as some surface vessels. A Sea Skua radar receiver, normally resident in the missile’s nose, was mounted in the large nose radome of Canberra B6 XH 568 and we spent a lot of time flying over the sea at very low heights pretending to be a missile. Naval ships were arranged for us to ‘attack’ and the Marconi man in the back played with the kit to analyse how well it was doing. As the system was coming to maturity in 1979 a trial was arranged in the Cardigan Bay danger area to finally prove the system before trial firings of the real thing from a Sea King helicopter. The brief was that we were to fly under the Sea King, which would be hovering at 500ft and illuminating a ship target with its ‘Seaspray’ radar. I would then fly as directed by the FTO who was watching the radar return as seen by the missile receiver. Well, it was good in theory but as we did our first pass under the helicopter, simulating the launch of the Sea Skua, there was an almighty thump and momentary downward movement as we flew through the considerable downwash. As we were at 100ft this gave me a bit of a start. I had considered the downwash but thought that with us flying at 350kt it would not have any meaningful effect. Suffice to say that, for the subsequent passes, we asked the helicopter to go up a bit and we passed beneath at 250ft, then descended to 100ft after a hundred yards or so.
The Harpoon was an American weapon, but its performance against ship targets in rough seas had proved to be unsatisfactory for RN operations. Hence a UK avionics company had been subcontracted to improve the radar’s performance. This naturally led to us having to arrange naval sh
ip targets in rough seas. One day I was dispatched in Canberra B6 WT 333 to an area midway between northern Scotland and Norway where we were to rendezvous with a Dutch frigate. The weather there was forecast to be such that the winds would have raised the waves enough to give a high Sea State (SS). Like the Beaufort Scale for winds the World Meteorological Organisation gives a numerical rating for SS. We needed SS 4–6; which is rough or very rough, with wave heights between 2.5 and 6m.
We flew out at high level to a point about 25 miles short of the RV and I let down into some very thick cloud, hail, snow and rain with a lot of turbulence. We broke cloud at about 1,000ft above a steel grey sea, heavily streaked with white breakers and spume. I was in radio contact with the ship and my navigator, Geoff Holt, gave me a steer towards it. Mr Pope, sitting next to Geoff, in the cabin behind me was working the radar. It really was rough as I descended towards 100ft to simulate the missile’s final attack height. The trouble was that the waves and the underlying swell were moving the sea surface up and down so much that a truly constant height above the sea was impossible. I did my best as I searched ahead for anything that looked like a frigate.
‘About 5 miles to go,’ announced Geoff.
I could see nothing but sea! Then the top of the farthest wave looked like it had a square lump superimposed on it. No sooner had I seen this weird apparition than it disappeared. Ten seconds later it was back: a large, grey, rectangular block on top of a wave! Gone again. When it came back into view once more we were much closer, after all we were travelling at 300kt. Now I could see something whirling around at the bottom edge of the square. Then it clicked. I was looking at the underside of the stern of the frigate with its prop coming out of the water momentarily as it slid down the next wave!
