A handful of helicopters of the 239.OGVP from Oranienburg (1), a unit which was directly subordinated to the 16.VA headquarter, had been made available for the Ministeriums für Staatssicherheit (Ministry for State Security, better known as Stasi) for electronic and photographic intelligence missions code named RELAIS II, between 1983 and 1989. These helicopters were carrying multiband receivers, of which the antennas were located on the right side of the forward fuselage. Whereas the crew was Soviet, the personnel in the cargo hold was East German. The latter was composed of an interpreter, a photographer and two radio operators. Spy flights took off from Oranienburg, a base situated a few kilometres north of the French occupation zone, and followed the West-Berlin borders in a clockwise direction. Data about the Allied communications systems were collected and various military communication and listening equiments were photographed as well from the rear cabin window.
A video camera mounted on a stabilised platform, was sometimes used to identify more easily the places where photographs had been taken. It was also a good means to estimate the position of the antennas observed during the flight. A typical flight lasted 100 minutes at an altitude of 100 meters at a flying speed of 110 km/h on average. When necessary, the helicopter could climb to 200-300 meters and fly at a lower speed to photograph some targets. Some electronic intelligence gathering could require a climb up to 1600 meters. The informations collected by the East German agents were of course shared with their Soviet counterparts, the KGB (2). The Mi-8 were sometimes "escorted" by Allied aircraft or helicopters based at Tempelhof (Bell UH-1H and possibly Pilatus UV-20A - Berlin Avn. Det.) or at Gatow (Gazelle AH.1 - 7 Flight AAC, DHC Chipmunk T.10 - RAF Gatow Station Flight). We ignore if Alouette III, Cessna L19E (DETALAT) or the MH-1521M Broussard and later the single DHC-6 Twin Otter (Armée de l'Air) of the French forces based at Tegel made such encounters.
Les consoles des opérateurs est-allemands à bord d'un Mi-8 du 239.OGVP lors d'une mission "RELAIS" le long des frontières de
Berlin-Ouest. © V.Liebscher.
The Berlin Control Zone was a circular area with a radius of 20 miles and a ceiling of 3000 meters. Its center was situated
at Kleistpark, north of Tempelhof, in the former building of the Allied Control Authorities. As mentioned earlier, the BCZ
was connected to the three air corridors of West-Berlin.
Soviet and East German aircraft could cross freely these corridors. The Allied aircraft could fly through them and inside the
BCZ itself. The helicopters however couldn't fly outside the limits of West-Berlin itself.
Largely unknown during the Cold War and almost unbelievable, the Allied aircraft based in Berlin flying with agents of the Military Liaison Missions to the Soviet Supreme High Command in Germany aboard, could therefore overfly and photograph these targets. They were sometimes disturbed during their "work" by lighting rockets or fighters crossing their path. Moreover, discreet Allied electronic and photographic intelligence aircraft could fly through the Berlin air corridors. The French flew regularly with Nord N2501 Gabriel - replaced by two C160 Gabriel in 1989 - of the EE.54 based at Metz along the German and the Czechoslovak borders and inside the Berlin corridors. They landed at Berlin-Tegel before heading back home through a different corridor. "Baltic" missions implied a fly through the north corridor after the take off from Tegel in order to join the Baltic Sea. They flew up to the Polish border before flying back home to Metz via a stop over at Tegel. They were sometimes interecepted by Soviet or Swedish fighters above the Baltic Sea.
The Americans were flying specially equipped C-130E of the 7405.OS from Rhein-Main during the eighties (radio call signs "Ask" and "Herky"). Beside the intelligence flights inside the air corridors themselves, they were the only one to venture above the BCZ with such aircraft. According to ATC controllers, they even overflew the international civil airport of Berlin-Schönefeld and its trafic at 1500 feet. Moreover, these flights had priority over the western civilian trafic. The British flew photo reconnaissance missions inside the corridors and above the BCZ with venerable Percival Pembrokes. If Military Liaison Missions were disbanded in 1990-91, the collection of informations about the new Russian army continued through by other services in Germany. Flying rules changed also after the German unification. The Allied aircraft could now fly through the BCZ and inside the area located between the north and the south Berlin air corridors, whereas the helicopter flights were authorized inside the whole area. However, the new official limits seemed much harder to respect by the Allied pilots who made quite a lot of "navigational errors" and overflew off-limits military installations! However, the Russians did not seem to complain but it is true that the die was cast. In fact, the real new limit was the aircraft and helicopter range: they were not allowed to land on a former East-German base to refuel.
> An analyse of the picture at right can be consulted here
- Most of the information about the Mi-8 ELINT missions over Berlin come from the book of Volker Liebscher "RELAIS".
Un Su-7 au-dessus de Berlin-Ouest le 7 avril 1965. © Flight.