In the mid-1930s, the German high command was dominated by the view that the main threat to the formation and expansion of the ‘Thousand-Year Reich’ was France. Furthermore, Hitler considered Britain a potential ally. However, the ubiquitous Abwehr stretched its secret tentacles in the direction of England. In 1936, the National Security Division of Military Intelligence (MI5) had exposed and arrested the Abwehr-I agent Lieutenant Gortz. He was sentenced to four years in prison. After that, the Führer ordered a halt to all espionage activity in England. But then he relented and in early 1937 this work was resumed. By September 1939, Abwehr-I had 253 agents in British territory.
But the possibilities of intelligence were limited, and for a long time Hitler refused to authorize reconnaissance flights over the UK. But both the Luftwaffe and Abwehr made illegal attempts to act in this area. He 111s of Fliegerstaffel z.b.V., under the guise of civilian Lufthansa airliners, photographed ports on the south and east coast of England, the London docks and other military facilities.
Of particular interest to the Germans was the British work on radio direction-finding, which later became known as radar. In Germany, very little was known about this project. The Abwehr received important information from an agent in England, who reported the construction of facilities along the entire south and east coast (from the Isle of Wight to the Orkneys), which the agent himself called ‘UKV-radio stations’. The same source said that similar stations were already operating in Suffolk, Essex and Kent, which could easily be identified by the characteristic steel or wooden towers with antennas. This was information of exceptional importance. The Germans knew that the British had been building radar stations since 1938.
Radar reconnaissance was entrusted to the Rowehl Group. Between May and August 1939, it made a series of secret flights across the North Sea to the east coast of England. As well as a few He 111s, the passenger airship LZ-130 Graf Zeppelin II was used, ostensibly undertaking ‘test flights’.
It was the world’s largest rigid airship, which made its first flight on 14 September 1938. It had a length of 245m and a volume of 199,981m3. The airship was driven by four Mercedes-Benz diesel engines with a capacity of 1200l/s. On board the Graf Zeppelin II were experienced observers, including Siegfried Knemeyer of Aufkl.Gr.Ob.d.L. The purpose of these missions was to determine the strength of the electromagnetic field created by the British radio direction-finders, and their location. But the tools used were extremely primitive. One of these ‘special means’ was the ‘tourist wagon’ – a small gondola that could accommodate one person. When the airship was hiding in the clouds or flying over them, the gondola was lowered on a cable down to be able to observe. The length of the cable reached 800m, but when released to its maximum length. The gondola carried away far to the side. A telephone wire was attached to the cable, through which the observer maintained constant communication with the crew of the airship.
During these reconnaissance flights, the LZ-130 managed to intercept and record many different radio signals, which, the Germans assumed, were emitted by the latest English radio direction-finders. Photographs were taken of all radio towers of unknown purpose. All the data was immediately sent to Generalmajor Wolfgang Martini, chief of Luftwaffe communications service. He forwarded them to his specialists who were engaged in work in the field of radar.
After processing and analysing all the recorded signals and photographs, the Germans concluded that British research in this area was lagging far behind the Germans. But in reality, this hasty conclusion was a mistake. The British from the very beginning were aware of the purpose of the airship’s ‘test flights’. They deceived the Germans, using old models of their radio direction-finder to track the Zeppelin.
In August 1939, international tensions in Europe increased rapidly. Anglo-Franco-Soviet negotiations on a military convention, held that summer in Moscow, did not yield results. In mid-August, the British press was already reporting that a new war would begin before the end of the summer. On 23 August it became known that the Soviet Union had signed a treaty of friendship and non-aggression with Germany. ‘The ten-year term of the Treaty, established by article VI, indicates that both parties are striving to consolidate peaceful relations between the countries for a long period of time,’ stated the Russian newspaper Pravda, the main organ of the Communist Party.
The conclusion of the Treaty between the USSR and Germany is an obvious fact of international importance, because the Treaty is an instrument of peace. It will not only strengthen good relations between the USSR and Germany, but will also serve to consolidate peace. Friendship of the peoples of the USSR and Germany, driven to a standstill by the enemies of Germany and the USSR will enter an era of prosperity.
Soviet propaganda claimed that the signing of the treaty (the Molotov-Ribbentrop Pact) would prevent war. The German press also rejoiced. Hitler said that in the great war of 1914–18, Russia and Germany had fought and become ‘victims’. ‘There will be no repetition of this,’ the Führer asserted.
But for Western Europe, this news was a real diplomatic bombshell. It was clear to everyone that the treaty opened the way to Poland for the Third Reich. British Prime Minister Neville Chamberlain immediately informed Adolf Hitler that the United Kingdom would not hesitate to fulfil its obligations under the mutual assistance agreement with Poland.
In this situation, OKW asked Luftwaffe to begin reconnaissance flights over British territory, as well as to conduct a ‘preliminary exploration’ of the main base of the British fleet at Scapa Flow. For such missions the long-range four-engined Fw 200 aircraft was best suited. At the end of August 1939 Deutsche Lufthansa transferred three such aircraft to the VfH: Fw 200V10 W. Nr.0001 ‘D-ASHH’, Fw 200V2 W. Nr.2484 ‘D-AETA’ and Fw 200A-03 W. Nr.2895 ‘D-AMHC’. First, the aircraft arrived at the Luftwaffe Rechlin flight test centre, which was 44km south-west of Neubrandenburg. There they were re-equipped with two Reihebild Rb50/30 cameras. Later, the aircraft were additionally fitted with defensive armament consisting of five machine guns.
On 29 August, the aircraft from the Rowehl group conducted aerial photography of objectives in southern England. At 13.41 local time a spy plane was noticed at high altitude above the town of Yate, 12km northeast of Bristol. Then he passed over Cardiff, then over the town of Barry, located 11km south-west of it, then turned to the south-east and, passing over Portland, disappeared over the English Channel.
But events evolved rapidly. On the morning of 1 September, Nazi Germany attacked Poland and the activities of the Abwehr, Rowehl and the Luftwaffe began a new phase …
New Equipment for Secret Missions
On 5 September 1939, a plane from the 1st Staffel Aufkl.Gr.Ob.d.L. flew over the British naval base at Scapa Flow. Then, on 21 and 22 September, scouts from the same group appeared over Northern France, conducting aerial photography of the airfields at Ruvre and Frescati, located near the city of Metz, and at Thionville. At the same time, Rowehl’s pilots began high-altitude flights over Belgium and the Netherlands, despite the fact that these countries had declared their neutrality. As a result, by the end of September, Luftwaffe command had complete information about the defensive precautions of these countries, including the location of air defence forces and military airfields.
Once war had been declared, the number of objectives for aerial photography grew rapidly. Soon the Luftwaffe recognized the urgent need to increase the Rowehl Group. On 24 September 1939 3.(F)/Aufkl. Gr.Ob.d.L was formed from 8.(F)/LG2 at the Jüterbog-Damm airfield (62km south-east of Berlin) and on 24 October 4.(F)/Aufkl.Gr.Ob.d.L was formed from 2(F)./Aufkl.Gr.121 at the Prenzlau airfield (44km south-west of Neubrandenburg) from the cr.
From autumn 1939, the Rowehl Group operated from three airfields. 2nd Staffel under Oberleutnant Karl-Edmund Gartenfeld remained in Oranienburg, which became the main base of the group. 1st and 3rd Staffel made reconnaissance flights over France from Fritzlar airfield, l25km south-west of Kassel. Flights over British territory were carried out from Ever airfield.
Aufkl.Gr.Ob.d.L. was an elite aviation unit that carried out secret strategic missions. Therefore, it received new aircraft as a priority. In November the 3./Aufkl.Gr. Ob.d.L. received two prototypes of the recently appeared Junkers Ju 88 – V13 W. Nr. 880005 ‘GU+AH’ and V14 W. Nr. 880006 ‘D+APSF’ with the Jumo engines. Rowehl pilots had to conduct operational flights to test their suitability as scouts. After installing two RB 50/30 vertical cameras, which allowed photography from heights up to 8,500m (28,000ft), and two RB 20/30 inclined cameras, which took photos from heights below 2,000m (6,500ft), they were given the designation Ju 88A-1/E. Later, the Rowehl group received three more used Ju 88s: V23 WNr.880023 ‘NK+AO’, V24 W. Nr. 880024 ‘D-ASGQ’ (‘NK+AP’) and V28 W. Nr. 880028 ‘GB+ND’. Initially, they kept the factory designations, then in the process of operations the aircraft received the codes Aufkl. Gr.Ob.d.L. (‘T5’) on the fuselage.
In early 1940, the 1st and 3rd Staffels of Aufkl.Gr.Ob.d.L. were equipped with Do 215B aircraft. This was a modification of the Do 17Z bomber, originally intended for export to Sweden, Hungary, Yugoslavia and even the Soviet Union. The new aircraft was almost identical to its predecessor. The new designation was invented specifically for export aircraft. One of the serial Do 17Z-0, which had a civil code ‘D-AIIB’, was renamed the Do 215V1 and was used for demonstration and advertising flights. Afterwards the aircraft was fitted with DB601A engines with a capacity of 1075 l/s. In this version, thirteen Do 215s were built for sale to Sweden, but in early 1940 the contract was terminated. All the machines were urgently altered to long-range scouts. In January–February, they came in a group to Rowehl. In March 1940, Dornier produced a modification of the Do 215B-4, specially designed for long-range intelligence-gathering and by May 1940 there were already twenty-four aircraft of this type in Aufkl.Gr.Ob.d.L.
Do 215s were equipped with three cameras: one was intended to shoot individual images, and the other two, mounted on the sides of the fuselage, for panoramic views. The viewing angles of the lenses of the last two cameras were set at 30° or 60°, depending on what had to be increased – the accuracy of photography (using overlapping frames) or its area.
At the beginning of 1940, Aufkl.Gr.Ob.d.L received two exotic four-engined aircraft, the Blohm und Voss BV 142. They were built at the aircraft factory in Hamburg on the basis of the large Ha 139 seaplane. The alteration was very simple – instead of floats a conventional wheeled undercarriage was fitted and the regular engines were replaced with more powerful BMW 132Hs. The first prototype – Ha-142Vl ‘D-AHFB’ – took to the skies in October 1938. Soon three more aircraft were put into operation. Initially, these machines were intended for postal flights over the North Atlantic. After the rejection of the designation ‘Ha’ all ‘Hamburgs’ were renamed BV 142s.
The war changed the use of these aircraft, like many others. Prototypes V3 and V4 were converted into transports and soon used in the Norwegian campaign to ferry troops. Prototypes V1 and V2 became long-range reconnaissance aircraft. They received a fully-glazed nose and a defensive armament of five 7.92mm MG 15 machine guns. After that, both machines were transferred to 2.(F)/Aufkl.Gr.Ob.d.L., where they performed reconnaissance flights over England. Sometimes BV 142s were used for the delivery of agents.
BV 142s V2 ‘T 5+B’ and V1 ‘T5+CB’ were used by the Rowehl Group during that year. These aircraft had a long range, but had significant drawbacks. Their maximum speed was only 375km/h. There was no communication between the front and separate rear fuselage, therefore the tail gunner was completely isolated from the rest of the crew. In addition, their use was badly affected by the lack of spare parts. In 1941 all four of the BV 142s were decommissioned.
Group Rowehl played a major role in the preparations for the Nazi invasion of Denmark and Norway. This operation was codenamed Weserübung (‘Weser Exercise’). When, in early 1940, Hitler decided to seize Norway, it suddenly became clear that OKW did not have up-to-date intelligence information that was necessary for the planning of the invasion. The time for planning the operation was extremely limited, so it was necessary to act quickly and decisively.
Oberstleutnant Theodor Rowehl was ordered to immediately conduct aerial photography of the entire southern coast of Norway from Oslo to Bergen, as well as Trondheim fjord and the port of Narvik in the north of the country. Of particular interest were the coastal fortifications and batteries in the Bay of Bohus and the airfields around Oslo. To fly the long distances involved Aufkl.Gr.Ob.d.L got a new Fw 200C-1, ‘BS+AH’. The pilot was Cornelius Noell, one of the best Luftwaffe reconnaissance pilots, and his navigator was Siegfried Knemeyer.
It was decided to start the mission from the airfield at Königsberg in East Prussia. This was done because in the case of a take-off from Northern Germany, the ‘illegal’ scout risked being spotted by British warships patrolling the North Sea. After leaving Königsberg, the Condor flew the first part of its route over the neutral waters of the Baltic, gradually gaining altitude. To shorten their journey, Noel and Knemeyer flew over neutral Sweden. Civilian Fw 200s from Deutsche Lufthansa frequently flew over Sweden (route Berlin–Malmö–Stockholm–Oslo–Copenhagen–Berlin), therefore, the Condor’s appearance caused no alarm.
In addition to ‘BS+AH’, other Aufkl.Gr.Ob.d.L aircraft, including the BV 142s, carried out reconnaissance missions over Oslo, Kristiansand, Stavanger, Bergen and Trondheim. As a result, by mid-March 1940, OKW had detailed aerial photographs of all strategically important areas of Norway. Rowehl Group had once again proved its importance. On 9 April 1940 Weserübung began.