Looking Down the Corridors

by Kevin Wright

  The modification programme had problems. The development and installation of fixed aircraft attachment points for the removable elements of the frames was a key task. Because the Pembrokes had been hand-built, rather than jig-built, each aircraft was unique, so each set had to be custom-built. This meant it was impossible to construct a standardised, interchangeable set of components until the differences between the three aircraft were properly identified. The construction of the frame for the third aircraft was only started after these problems had been overcome on the first two aircraft, which considerably delayed the programme. Company representatives had to visit Germany in September 1965 before there was much progress. The third aircraft was so different from the other two, that the fixed fittings were unlikely to be compatible with the removable ones. The original intention to have just two sets of removable fittings to keep two aircraft available was abandoned and a third set was purchased.28 The delays were so long that one aircraft in the ‘old’ camera fit (inaccurately listed as WV796) was retained in service until the third ‘fit’ aircraft became available.29 In late 1966, financial approval for a third ‘new’ fit aircraft (XF799) was granted and what should have been a relatively straightforward modification programme turned into a tortuous one that lasted over four years.30

  Another major problem was designing an electrically activated ‘fogging’ device. Development of this modification and manufacture of the 250 and 500ft magazines was by Williamsons and managed by Faireys. The intention was that, in an emergency, the switches would be thrown and the exposed film rewound over a light source to completely over-expose the imagery, rendering it totally useless. This was expected to take some four minutes for a 250ft magazine and seven minutes for the 500ft one. Difficulties in resolving these problems significantly delayed the entry into service of the new camera fit. Missions with the new F.96 installation began on 23 November 1964, but without the oblique cameras. The ‘fan’ cameras could be used because they had a manual fogging device and used shorter film magazines in the interim. It was not until 1967 that the Pembrokes began to fly with the full F.96 fit.31

  Squadron Leader Phil Chaney, 60 Squadron navigator and later CO (1988–90), explained:

  around 1980, more modern camera equipment became available to us – similar to that then used on the U-2 which gave us true horizon to horizon coverage. The resolution on those cameras was much higher and therefore more susceptible to the effects of vibration.

  That became a problem on one particular aircraft – XL953. This had constant vibration problems which affected the aircraft’s photographic performance. Despite many efforts the vibration was never really rectified, although it was ultimately solved in a rather drastic way:

  On 16 May 1980, the aircraft was being prepared for deep maintenance at RAF Wildenrath. A static charge ignited some remaining fuel being drained from it and the resulting fire saw the hangar roof damaged and half of XL953 burnt out.

  The story has since become part of squadron folklore. Later that day the new CO, Squadron Leader Andy Spanner, was greeted on his return to Wildenrath reportedly with: ‘Boss, good news is we’ve managed to sort out the vibration problem on ’953. Bad news is the aircraft is burnt out!’32

  Flying the Corridor

  Flight Lieutenant David Clark, who had previously flown Pembrokes with 152 Squadron in the Middle East during the mid 1960s, was posted to 60 Squadron for a second Pembroke tour in May 1975:

  I remember on my arrival at Wildenrath, we were shown around an aircraft in the hangar by the Boss. Being experienced on the type I noticed all sorts of funny pipes and things on the inside of it, so I asked what they were. The Boss casually said ‘just ignore it’, which I did. I had no idea that we were doing the reconnaissance flights until some months later when I was introduced to the role. The reconnaissance side of the operation was never spoken about. One began to think that something funny was going on because the aircraft ‘in fit’ was always parked directly outside the squadron – on the first slot. Only that aircraft was allowed to park there and with its door always facing the hangar. The curtains were always drawn and it was kept locked.

  Brian King’s first experiences were a little different:

  I knew nothing about the reconnaissance role. But then you noticed aircrews whom you didn’t know or have any idea what they were doing. That there was an aircraft that always has closed curtains, always kept in the hangar when not flying, never just parked outside. People were careful who was around when it was out and no visitors allowed near it.

  He said that the Boss introduced him to the role ‘with a very brief, briefing’. ‘Very few on the Station knew what we did. But people did notice the oddities of your behaviour.’ ‘We always had ad hoc crews. We would get the programme about a month ahead and so would know roughly when we would be on standby, a scheduled trip and so on.’

  Within 60 Squadron, certainly not all the air and ground crews knew what the ‘fit’ aircraft and their crews were doing. Phil Chaney told us, ‘knowledge of Operation Hallmark was kept very closely guarded with only a very small number of people on the Station having full knowledge.’ At that time there would be only thirty-four people with full access to the details of the programme: fifteen on the squadron, the Station Commander, Station Intelligence Officer and OC Ops Wing, C-in-C RAFG, his deputy with the rest in London in the prime minister’s Office, Secretary of State for Defence and Cabinet Office. Operation Hallmark was also kept closely guarded at HQ RAF Germany and HQ BAOR at Rheindahlen; official knowledge of the ‘clandestine photography’ flights was restricted to those RAF and Intelligence Corps personnel analysing the imagery itself, senior staff officers and others involved in their duties within the Reconnaissance Section. There was also a wider grouping at Rheindahlen and Wildenrath aware of at least elements of the tasking – even if not officially briefed on the full operation. This would have included photographic technicians, maintenance crews and some members of BRIXMIS.

  A number of select personnel at RAF Gatow also knew the purpose of the ‘special fit’ Pembrokes visiting the airfield. Peter Kirkpatrick of the Aircraft Servicing Flight (ASF) was one of those, serving at RAF Gatow and completing his tour in January 1988:

  The ASF always had good advance warning of flight arrivals, nobody was going to carry out an emergency diversion 100+ miles up the corridor, after all! The only real exception to this was ‘that’ Pembroke which was known to us as ‘The Unsched’. We could use this term in front of other people if necessary without giving much away. To cover the short notice availability, we were on call and carried a pager, which normally frightened the hell out of us if it actually went off.

  Over the years the photographic reconnaissance sorties developed into a stable routine. Aircraft usually flew to Berlin down one Corridor and exited via a different one. The journey time on Southern and Central routes was two to two and a half hours, considerably longer on the Northern Corridor. Once in the Corridor the aircraft generally flew at 3,500ft, if cloud conditions allowed. The exact route and altitude would depend on the targets for the flight and flying conditions. The Pembrokes’ flight path down the Corridor was a very erratic one, unlike most regular Corridor traffic that strictly adhered to the centreline, following it rigidly all the way in and out. Crews were acutely aware of the dangers involved in flying Corridor missions, when very minor mistakes in navigation could result in tragedy. If a photographic Pembroke had ever come down in GDR territory, the British would have tried to deny that the mission’s task was photographic.

  Crews were generally assigned to flying the Corridor for a week, usually completing one round trip during that time, sometimes two. On the Monday they were told the outline flying plan for the week. This was matched with the weather forecasts, clearly crucial for successful missions. Likely flight days might be vague – depending on expected Soviet military activity levels. Dave Clark again:

  the Navigator got the prescribed route from HQ RAFG at Rheindahlen. We would generall
y take off by about 10.00 and use a standard routing to a Corridor entrance. Once in the Corridor it was down to the navigator how close we went to the edge of it. One navigator was up front, next to the pilot and the other down the back operating the equipment.

  Paul Hickley, a 60 Squadron navigator, explained their two different roles:

  The front-seater was responsible for all of the route navigation, including preparing both the navigation flight plan and the Air Traffic flight plan notification. The rear-seat navigator could not see forwards and so, for vertical shots, had to rely entirely on the front seat navigator (or occasionally the pilot) for information on when to switch the vertical cameras on. However, he did have a vertical sight, a drift-sight, rather like a downward-pointing telescope, that could act as a track indicator. If the initial line-up was less than ideal, the navigator could ‘talk’ the pilot onto the right line once he saw the target. The pilot would then use coarse (indeed, rather agricultural) applications of rudder, whilst trying to keep the wings level, because a gentle turn with bank would have displaced the target from the centre.

  Most important of all, the front seat navigator was to ensure that the aircraft stayed within the Corridors. These only extended 10 miles each side of the centre-line and some of our vertical targets lay very near indeed to the Corridor edge. We were always advised that we faced the possibility of being shot down if we strayed outside. Watching the Pembrokes on their radars, this would sometimes make the air traffic controllers in the BARTCC rather nervous until they got the message that the Pembrokes were best left alone to go about their business. Most bona fide air traffic in the Berlin Air Corridors hugged the centre-line, as we did ourselves when not on Hallmark missions, because they knew the risks of not doing so. Our job required us to go to the edges, and it concentrated the mind.

  Brian King added that:

  we had some ridiculous stories to justify what we are doing – such as a navigator on a ‘chop ride’ trying to pass the course so don’t push us back. Then someone would realise that they should leave us alone. Inside the BCZ, ATC would sometimes give you vectors away from edges. So you would ask, ‘are you giving me a mandatory vector to fly?’ and again we would try to subtly remind ATC that we were doing something different.

  Paul Hickley:

  Many of the targets were 10 to 15 miles outside the corridors and were perfectly open to photography if the visibility was good enough. The F.96 oblique cameras had a sight-line that could be varied by a manual spring balance adjustment from the horizontal to about 15 degrees depression angle. If the rear-seat navigator saw the target out of the side windows in good time, he could adjust the camera down to the correct depression angle by visual estimation. Once the camera was in line, he could squint down the barrel (the lens assembly looked like a telescope and filled much of the cabin’s width) and ask the pilot to make any final adjustment required by a combination of bank and rudder, which kept the wing down the right amount but didn’t change heading. If he picked it up late, the whole aiming process would have to be done by talking the pilot on to the right angle of bank, because the camera angle motors were quite slow. The pilot needed to keep the aircraft as steady as possible to enable cameras to function properly without blur and on target.

  Brian King pointed out:

  Each flight had routine and unique elements, but were rarely identical. We might be briefed on a mission to overfly what was likely to be a training exercise outside of the normal pattern. That might be a precursor to a deployment taking place at a given time and location. Then when we actually got there we would find just a caravan obviously pushing out transmissions and spoof material. We had a standing brief not to miss targets of opportunity. Some were at limits of visibility – so what they actually got from it I am not sure. Training areas stood out particularly clearly from the air. Most things stood out because of the differences around them. Particularly in GDR, if something was neat and tidy it normally meant it was important. Sometimes we would go and photograph a point even if nothing was visible to us. Pilots rarely got to see the pictures. I always tried to take something on a flight to get a smile from the guys in PR. I once took a picture of a hot air balloon in mid-flight by lifting the Pembroke’s wing and they later sent me a copy of the picture which I still have.

  On approach to RAF Gatow the crew would switch off the equipment and close the curtains. After landing they would always park in the same place with the door opposite the hangar so that the East German Border Guards, in the nearby watch towers, could not see into the aircraft. Outdoors crews had to be careful in conversation as directional microphones were used by some watchtowers. Brian King, as many other pilots did, had a high opinion of the ground handling in Berlin:

  At RAF Gatow, the ground crew from the ASF were responsible for the Chipmunks but also for us. They were selected as being above average guys, so the aircraft would be turned round as quickly as possible – one of the best pre- and post-flight services you could get. These guys were highly motivated and were very good at their job. Then we were ready to go off on a local sortie when told to do so.

  Off the flightline, ‘in fit’ crews had access to a secure room, from where they could talk more freely. Peter Kirkpatrick explained:

  It must be said, the Pembroke crew were more chatty about where they had been, than the Chipmunk crews. They would mention where and who they had been looking at, sometimes pointing stuff out on our wall map. I must be clear that this was not an operational briefing, more a ‘bit busy round there’ sort of chat over a brew. Also, we could normally tell from the amount of urgency in the crew if they had been ‘busy’. After most flights they would saunter around and have a cuppa with us. But some days there was a bit more urgency, wanting to get fuelled up and in the air again for either a ‘local’ or a return flight.

  The pilot would create a fictitious ‘snag’ on the aircraft, always something relatively minor, but requiring an air test after ‘rectification’. Dave Clark elaborated:

  the fault on the RAF ‘Form 700’ was never declared to ground crew. So when I put a snag in the sheet I also removed it from the ‘700’ afterwards and destroyed it, so to all intents nothing was ever wrong. For the overnight stays the aircraft would be fuelled, locked and left with the film on board. We tended to keep away from the Gatow mess because we might be asked questions, so we would often stay down town at the Edinburgh House military hotel. At Gatow, on the following morning, we would speak to Rheindahlen on the secure phone to check our outbound route.33

  Brian King took up the account:

  the airtest generally took place in the afternoon, or perhaps the following day if weather, or planning, required it. The flight would usually necessitate flying around the BCZ – particularly close to its edge with the cameras working at from 2,000 to 3,500ft. Often in winter we were limited by weather windows, so we would have to be flexible as to when flights would take place. We would then return to RAF Gatow to stay overnight. Being able to stay in Berlin was one of the good parts of the job, being able to have a good meal and a few beers.

  Whilst the Pembroke crews may have been enjoying time off in Berlin, the ASF were responsible for the aircraft while it was on the ground at RAF Gatow. Peter Kirpatrick described:

  The ‘Unsched’ was kept closed and locked at all times when it was with us. The door locks must have been sourced from the same place as Austin-Morris got theirs. If I remember correctly my old Morris Thousand boot key fitted it! The only thing that was taken off it outside would be that lovely big wooden crate they called a ‘lunch box’. If anything needed to be removed from the aircraft we would push it in to the hanger and close the doors first. The curtains were still kept drawn inside, but at least we could then remove the large ‘briefcase’ which contained a very nice high-speed hand-held camera (kept locked in a separate cabinet). Other than that we didn’t really have anything to do with the ‘special fit’ aircraft.

  Generally the following day, with ‘fault’ cleared,
the Pembroke departed, repeating the inbound procedure in reverse. It was standard practice that flights in and out of Berlin were flown along different corridors so as to maximise target coverage. Peter added that ‘we never flew outside the permitted boundaries. We would have been mortified to do so, because it would have meant our navigation was inaccurate.’

  On arrival at RAF Wildenrath the Pembroke would be towed into the hangar and the film quickly removed. The crew would be debriefed at Rheindahlen and the films processed as a high priority at the Photographic Reconnaissance Unit (PRU), often within a couple of hours. Once printed the images were examined by PIs from the co-located RAF Photographic Interpretation/Intelligence Department (PID) and BAOR’s 6 Intelligence Company.

  The attempts to hide the true role of the camera-equipped Pembrokes saw them operating alongside the squadron’s ‘standard’ communications and VIP transport aircraft. As part of their extended cover, the camera-equipped aircraft also regularly took photographs of British bases and training locations in Germany to maintain up-to-date photography and justify their special configuration.34 If anybody asked why the aircraft were camera-equipped, the explanation given was that they were taking photographs of training areas to verify farmers’ compensation claims for military damage. Another story was that they were flying an urgent spare part into Berlin and were using the only available aircraft that just happened to be in camera fit. Aircrew kept flight time logged in their individual logbooks, where the Corridor reconnaissance flights are simply, if misleadingly, listed as ‘training’, ‘flight checks’ or other innocuous activities.35