The Dornier Do 17 was one of the main Luftwaffe weapons during the period of German Blitzkrieg victories during 1939 and 1940. Like many early Luftwaffe aircraft it had originally been developed as a civilian aircraft, in this case as a high speed passenger and mail plane for Lufthansa. Three prototypes were completed during 1934, and tested by the airline early in 1935. Lufthansa promptly rejected the aircraft because the slim fuselage made it an impracticable passenger plane – the six seats were split between two tiny cabins, with very poor access.
The aircraft was saved by obscurity by Flugkapitan Untucht, a record breaking pilot then liaising between Lufthansa and the RLM. He suggested that the aircraft might make a good fast bomber, a type then in favour with military aviators. The RLM ordered three prototypes, the first of which flew during 1935. The new version was slightly shorter than the original prototypes, and was powered by 750hp BMW VI 7,3 engines. It was blisteringly fast – the first production version had a top speed of 236 mph. Its narrow fuselage soon won it the nickname the “flying pencil”.
A specially constructed version was produced for the July 1937 International Military Aircraft Competition, held at Zurich. This was powered by two 1,000hp Daimler Benz DB 600A engines, and had been lightened as much as possible. At Zurich it reached a top speed of 284mph, and ran away from all foreign opposition. The same happened when the standard production version was sent to Spain, to take part in the Civil War. The high speed aircraft was able to easily escape from the fighters flying for the Republican Air Force. The Luftwaffe entered the Second World War convinced that its lightly armed medium bombers would be able to evade any fighter opposition put up against it.
The Do 17 performed well in Poland and France against disorganised opposition. However, just as the British had found in France in 1940, the Do 17 would soon prove to be very vulnerable in daylight against first class fighters. Two factors combined to make the German bomber forces more vulnerable over Britain than they had ever been before. The most important of these factors was the British Home Chain radar system, which allowed the RAF’s fighters to intercept incoming bombers, rather than have to conduct standing patrols or chase bombers that were already overhead. Second, both British fighters, the Hurricane and the Spitfire, could overhaul the Do 17, the Spitfire by some 50mph. The Do 17 would prove to be the most vulnerable of the German medium bombers over Britain, and would be largely withdrawn from the front line during 1941. Production of the Do 17 had ended in 1940 after 522 Do 17Zs had been produced.
Four Geschwader were equipped with the Do 17 during the invasion of Poland. There the type was often used as a dive bomber, while the He 111 carried out the level bombing. Once again the speed of the Do 17 allowed it to escape from danger.
France and the Low Countries
On 10 May 1940 the Luftwaffe still had four Do 17 Geschwader, with 338 operational aircraft out of a total strength of 422. Over the Low Countries and France the Do 17 played an important role in the attacks on allied communications and airfields. This time it was the speed of the German victory that protected the Do 17 from heavy losses, disrupting the Allied fighter forces and preventing the allies from gaining anything other than local air superiority.
Battle of Britain and Blitz
At the start of the Battle of Britain KG 2, KG 3 and III/.KG 76 were still using the Do 17, with the Ju 88 replacing it in other units. It now came up against a determined fighter opposition, and suffered heavy losses. Despite its speed, it suffered more heavily than the He 111 or Ju 88. Some Do 17 pilots were able to escape attack by going into a high speed dive, but that then prevented them from carrying out their bombing mission.
The Do 17 units played their part in the night-time blitz of 1940-41, but the type was no longer in production by the end of 1940, and only KG 2, III./KG 3 and KGr. 606 were still using the type in January 1941.
Greece and Yugoslavia
Four bomber groups used the Do 17 during the invasion of Greece and Yugoslavia, where the type was once again able to outpace its opponents. One unit remained in the area to take part in the attack on Crete, but the remaining Do 17 units moved back north to take part in the attack on Russia.
Russia and out of service
The Do 17 was only briefly involved in the invasion of Russia as a bomber. KG 2 used it on the eastern front during June 1941, before being withdrawn the following month to re-equip with the Do 217. A small number of Do 17s and the similar Do 215 remained in use with reconnaissance units until early in 1943, but with their replacement the Do 17 left front line service.
The E-1 was the first production version of the Do 17 bomber. It was powered by two 750hp BMW VI 7,3 engines, and could carry a maximum payload of 1,650lb/ 750kg. It entered Luftwaffe service in the summer of 1937.
The F-1 was a photo-reconnasiance version of the E series. It could carry two cameras in the floor – either the Rb 50/18 or Rb 50/30 – as well as extra fuel.
The K series were built for export to Yugoslavia. They were powered by 980 Gnome-Rhone 14 No. radial engines, and came in Ka reconnaissance and Kb bomber versions. Deliveries began in October 1937, and licensed production started in Yugoslavia in 1940. Two years later the Do 17K found itself facing the Luftwaffe’s Do 17Zs during the German invasion of Yugoslavia.
Export recon version for Yugoslavia, 980hp Gnome-Rhone 14 No. radials. Delivers from October 1937, license built in Yugoslavia from 1940
Two prototypes of the L series were built. Powered by the 900hp Bramo 323A engine, they could reach a top speed of 301mph, but were not placed into production.
The M-1 was the first production version to be powered by the 900hp Bramo 323A-1 Fafnir nine-cylinder air cooled radial engines. The bomb bay was extended to give the M-1 a maximum bomb load of 2,205lb/ 1000kg. It was otherwise similar to the E-1.
The M-1/Trop was a tropical version of the M-1.
This designation was used for aircraft that carried an inflatable dinghy, a valuable piece of equipment once the Do 17 had to cross the English Channel.
The P-1 was a reconnaissance aircraft, powered by two 865hp BMW 132N radial engines, which were more fuel efficient than the Bramos, giving this version a longer range. It was normally used with either a Rb 20/30 and an Rb 50/30 or a Rb 20/18 and Rb 50/18 depending on the targets to be photographed.
Two R series aircraft were built to test the DB 600G and DB 601 engines.
The two S series aircraft saw the Do 17 loose its slim profile. It was becoming clear that the aircraft was dangerously under-armed, and so the forward fuselage was bulged downwards to fit in a prone gunner manning a rear firing ventral MG 15. It also featured a fully glazed nose, and the pilot’s canopy was raised, enclosing the dorsal gondola. The aircraft now had a bulbous pod at the head of the slim fuselage.
The U series were pathfinder aircraft, equipped with a second radio operator and more advanced radio equipment. Three U-0s and twelve U-1s were built and were used by KG 100.
The Z series was the most important version of the Do 17. It featured the same bulged nose as the S series, and was powered by the Bramo 323A nine cylinder radial engine.
The first production version of the Z series, the Z-1 was powered by the 323A-1 Fafnir engine, which did not provide enough power. As a result the maximum bomb load was reduced in this model.
That problem was fixed in the Z-2, which was powered by two 1000hp Bramo 323P engines, with two-speed superchargers. This allowed the aircraft to carry a 2,200lb bomb load, a crew of five six 7.9mm MG 15s. These included two forward firing guns – one fixed and one moveable, one rear-firing gun in each of the dorsal and ventral positions and two beam guns, although these can not have been particularly useful as their field of fire was severely limited by their location next to the engines!
The 22 Z-3s were long range photo-reconnaissance aircraft, carrying two Rb 20/30 cameras in the entrance door position.
The Z-4 was a dual control trainer
The Z-5 was a long range maritime reconnaissance aircraft equipped with flotation bags
Z-6 “Kauz” (Screech Owl)
The Z-6 was a first attempt to produce a Do 17 night fighter. It combined a standard Do 17Z with the gun nose of the Ju 88C-1 fighter, carrying three 7.9mm MG 17s and one 20mm MG FF cannon. The type was not a great success and was soon replaced by the Z-10.
Z-10 “Kauz II”
The Z-10 was a more successful night fighter, with a custom built nose containing four MG 17s and two 20mm MG FF cannon, which could be reloaded in flight from the crew compartment. Only nine were built, and they had a short combat life before being replaced by the Ju 88C.
Bramo 323 P
53 ft 3.75in
265mph at 15,400ft
990 miles with 1760lb bomb load