During his posting to the Balkans in 1941, Bergen flew the Dornier Do 215, originally intended as an export version of the Do 17, but an embargo on German foreign sales saw the type absorbed into the Luftwaffe inventory, predominantly as a long-range reconnaissance aircraft. Bergen made a forced landing in a Do 215 in April 1941.

The Luftwaffe’s dependable Junkers Ju 52/3m was used in numerous roles throughout the war, not least of which was as a trainer for multi-engined aircraft pilots at Flugzeugfuhrerschule C (FFS C) flying schools, as attended by Karl Friedrich Bergen during 1936-38.

A previously unpublished family photograph of Karl Friedrich Bergen (furthest right) with a flight-test crew beside a freshly delivered Dornier Do 17R, probably at Oranienburg in late 1940/early 1941. The Do 17R was a specialised long-range high-altitude reconnaissance variant with two additional fuel tanks aft of the bomb bay. Only four examples were built.

A Dornier Do 17P-1 of 3.(F)/11 photographed on the snow-covered airfield at Kassel in January 1940. Along with the F variant, the P also equipped 2.(F)/Aufklarungsgruppe 121 with which Bergen served in September 1939. Note the oversized underwing national markings, applied following the Polish campaign to aid recognition from the ground by friendly forces.

Another type on strength with the FFS C flying schools was the twin-engined Junkers Ju 86, which had initially seen use as a prewar airliner on Deutsche Luft Hansa’s Blitzstrecken (“lightning stretch”, i.e. high-speed) routes, but which was also adapted into a bomber for the fledgling Luftwaffe. This Ju 86E-1 is seen in the colours of Kampfgeschwader 253.

Разведчик Ju 88D из группы (F)/122, советско-германский фронт, зима 1943 г.
Junkers Ju 88D-1 F6+DN of 5. (F)/122 has its engines run up on a cold day at Gosstkino in 1943 in readiness for another long-range reconnaissance mission over the Eastern Front. The Ju 88D-1 was also operated by 3./Aufkl.Gr. Ob.d.L., as commanded by Hauptmann Karl Friedrich Bergen in Russia from March 1942.

A Junkers Ju 88D-1, similar to that which Bergen would have flown while with 3./Aufkl.Gr. Ob.d.L. and 3.(F)/Aufkl.Gr.100. This example belonged to 3.(F)/122 based at Creil in France in the late spring of 1942, from where it provided long-range reconnaissance of the French coast, the English Channel and the Bay of Biscay.