Junkers Ju 290

The Junkers 290 was a direct development of the Junkers Ju 90 airliner, versions of which had been evaluated for military purposes. By 1941, two further prototype militarised Ju 90s were deemed to be different enough from their predecessors to warrant a new designation. These flew in mid 1942 and were quickly accepted into service and the type ordered into production. These two (Ju 290 A-0), plus the first five production aircraft (Ju 290 A-1), were completed as heavy transports, equipped with loading ramps in their tails and defensive gun turrets. Some of these aircraft participated in the Stalingrad Airlift in December 1942.

Production lines were set up at the Letov factory in Prague for the combat versions of the aircraft, commencing with the Ju 290 A-2, which carried a search radar for its patrol role. Minor changes in armament distinguished the A-3 and A-4, leading to the definitive A-5 variant.

Sources:
Gunston, Bill & Wood, Tony - Hitler's Luftwaffe, 1977, Salamander Books Ltd., London
Wikipedia: Junkers Ju 290