The Dornier Do 17K was the export version of the Do 17 for Yugoslavia in the 1930s. It differed thanks to its stronger French engines, larger bomb load and additional armament, making it more powerful than any of its contemporary Luftwaffe variants. Around 60 were available during the German invasion, and served with some success before being spread across Axis and Allied air forces.
The Do 17 Ka-1 and Ka-2 were upgraded versions of the German Do 17 E with the K-14NO engines and FN machine guns. The Ka-2 only differed slightly in having its defensive turret further back, and some appear to have been used for reconnaissance duty.
The Do 17 Ka-3 was based on the Do 17M-1, with duralumin-covered wing undersides, wider engine axis and longer engine nacelles.
The Do 17 Kb-1, Kb-2 and Kb-3 is used to refer to the three series of bombers license-produced in Yugoslavia under DFA. They received heavier armament, including a cannon and an MG placed in the windshield.
Length: 16.10 m
Wingspan: 18.00 m
Height: 4.55 m
Wing area: 55.00 m²
Empty: 5,643 kg
Max take-off: 7,660 kg
Engines: 2 x Gnome-Rhone K-14NO
Engine power: 2 x 649 kW (870 hp)
Maximum speed: 438 km/h
Range: 2,200 km
Flight ceiling: 8,500 m
Climb rate: 5000m altitude achieved in 12 minutes (-> 6.9 m/s average)
Do 17 Ka-1
2x 7.92mm nose-mounted Browning FN (one later moved to the windshield)
Do 17 Ka-2 [unclear if done for all planes of the type or just some]
None (nose MGs removed to house photographic equipment)
Do 17 Kb-1, Kb-2, Kb-3
20mm nose-mounted HS.404 (105 rpg), 13.2 mm windshield-mounted Browning MG
Defensive: 7.92mm Browning FN in ventral turret, 7.92mm Browning FN in dorsal turret
Suspended: 1200 kg of bombs (8 x 100 kg in bomb bay, 2 x 200 kg underwing)
As part of a modernization program, the Royal Yugoslav Air Force began looking for a modern bomber plane to license-produce in 1936, that was to be powered by the locally built K-14NO engines. The German Dornier Do 17 was one of the options available, and was selected thanks to Yugoslavia’s positive experience with the company’s Do D and Do Y aircraft in the past. The contract for the first 20 Do 17 Ka-1 bombers was signed on November 9, 1936, and the first of the series first flew almost a year later on the 6th of October, 1937. Only the lead plane had standard Luftwaffe equipment, as the rest were left to be equipped by the Yugoslavs themselves with Belgian FN machine guns, Czechoslovak cameras and more.
Already before the delivery of the first Do 17 Ka-1s, a new order was being discussed in the VVKJ. On the 18th of March 1938, a new contract was signed for the delivery of fourteen Do 17 Ka-2 and two newer Do 17 Ka-3 variants. Furthermore, in June 1938 a licensed production run of 36 Ka-3 bombers was agreed upon. For that reason, the DFA (State Aircraft Factory) was founded in Kraljevo on 21 March 1939 to handle the production. 33 of them were completed by the time of the German occupation, in three series known informally as the Kb-1, Kb-2 and Kb-3. The Dorniers produced in DFA were armed with a 20mm Hispano HS.404 and a 13.2mm Browning FN machine gun in the windshield.
In 1940, an additional deal for the production of 40 more Dorniers was signed, but it was soon replaced by planned Do 215s. Their production didn’t get off the ground either due to lack of delivered parts.
On the dawn of April 6th, 1941, the Petrovac airfield with numerous Dorniers was attacked by German planes, destroying 15 of the bombers. When faced with news of this disaster, nine of the Do 17K bombers in Kosovo set off on the Air Force’s first offensive operation to attack an advancing column in Bulgaria. The mission was completed with no losses, and several bombing missions followed that were overall successful, although more and more Dorniers were destroyed throughout April. The Do 17K took part in evacuation of government personnel and the last gold reserves out of Yugoslavia into Greece.
At least 23 Dorniers are known to have survived the invasion. Their fate is as follows:
- 2 successfully escaped to Allied Egypt, where they joined the RAF but remained grounded. Both were disabled by a German air raid on August 27, 1941.
- At least 18 were captured by the Germans, 6 of which were ceded to Bulgaria and 11 to Croatia.
- 2 were captured by the Italians, one of which was taken to Guidonia for extensive testing.
- 1 was used by the Royal Hungarian Army Air Force, who modified it to mount 4 of their domestic GKM machine guns and two reconnaissance cameras.
Examined by British soldiers in Paramythia, Greece, April 1941.
The Do 17K cockpit.
A picture of the Stankovic bomb carried under the Do 17, and information on how the bombs are carried.
Dornier Do 17 - The Yugoslav Story (available online)
Kraljevski Avioni (available online)