Dornier Do 17Z-2 | ||
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Description | ||
Role | Light bomber | |
Crew | four, pilot, bomb aimer/gunner, two gunners | |
Dimensions | ||
Length | 52 ft | 15.80 m |
Wingspan | 60 ft | 18 m |
Height | 15 ft | 4.55 m |
Wing area | 592 sq ft | 55.00m² |
Weights | ||
Empty | 11,484 lbs | 5,210 kg |
Maximum take-off | 19,500 lbs | 8,590 kg |
Powerplant | ||
Engines | 2 Bramo 323P Fafnir | |
Power | 2x 1,000 hp | |
Performance | ||
Maximum speed | 265 mph | 427 km/h |
Combat range | 721 miles (half load) | 1,160 km/h |
Ferry range | ||
Service ceiling | 27,000 ft | 8,200 m |
Armament | ||
Guns | 7x 7.92 mm MG 15 | |
Bombs | 2,200 lbs | 1,000 kg |
The Dornier Do 17, sometimes referred to as the Bleistift ("pencil") by its pilots, was a World War II light bomber produced by Dornier that was used for a short time by the Luftwaffe. It quickly became outdated, and was removed from front-line service as soon as enough Junkers Ju 88's were available. A small run of an updated version known as the Do 215 was also produced, and ended almost as quickly.
Table of contents |
2 Do 17E and F 3 Do 17K 4 Do 17L and M 5 Do 17P 6 Do 17S and U 7 Do 17Z 8 Do 17Z-10 Kauz 9 Do 215 |
When Lufthansa started expanding in the early 1930s they placed orders for planes that pushed the state of the art, and a number of companies took this opportunity to invest in new design and construction techniques. The result was a number of world-beater designs like the Heinkel He 70 Blitz and Focke-Wulf Fw 200 Condor. In 1933, Dornier thought it would enter the market as well, and started the design of a fast twin-engine plane in response to a Lufthansa tender for a six-passenger mail plane. The result was the Do 17.
In order to compete with planes like the He 70, the Do 17 was made as small as possible in cross section to reduce drag. The plane was so skinny that it quickly earned the name flying pencil (bleistift). Three prototypes were built for Lufthansa and were tested in 1935, but they were eventually returned to Dornier. In test service the passengers complained that it was terribly uncomfortable inside the tiny cabin, they even had a hard time just getting into it.
As luck would have it, a former Dornier employee and new Luftwaffe pilot, Flugkapit�n Untucht, visited the plant and test-flew one of the prototypes. He decided that it had potential as a light bomber, but felt it needed more vertical surface for stability. Soon the RLM (the German Air Ministry) asked Dornier to produce seven more prototypes for combat trials with a new twin-rudder design. The design was successful, and the plane was looked upon as the first example of the schnellbomber concept: bombers built to be fast enough to outrun fighters. For a time it was felt that bombers would retain their speed advantage over fighters due to their extra power, leading many to assume that the bomber will always get through.
The prototypes had mounted the excellent Dailmer-Benz DB 600 engines, but these were constantly in short supply. Production started instead with the BMW V1 radial engine, creating the Do 17E-1 bomber and Do 17F-1 reconnaissance versions. The bombload of the E-1 was a measly 500kg, and the two defensive MG15 machine guns were in a hut on the roof and a small hatch in the floor that offered almost no angle of fire.
After seeing the Do 17M at the Z�rich air races in 1937, the Yugoslavian Air Force bought licence rights for production at Drazavna Fabrika Aviona. They equipped it with the considerably better Gnome Rh�ne 14N engines and added a 20mm Hispano cannon and three 7.92mm Browning machine guns. Seventy had been produced by April 1941 when the country was invaded by German forces. Most were destroyed but two of them fled the country with a load gold on board.
The feasibility of the schnellbomber was tested at the International Military Aircraft Competition at Z�rich in 1937, where the Do 17M prototype finished ahead of all the fighters in the competition.
The supply of the DB 600 was extremely limited, and priority had to be given to the Messerschmitt Bf 109. Production versions of the basic M model airframe where then fitted with the new BMW Bramo 323A-1 Fafnir of 900hp, which gave reasonable performance and raised the bombload to 1,000kg. The resulting Do 17M-1 was produced in small numbers and operated until the first year of the war, when they were withdrawn and sent to training units.
Do 17P-1 |
Another two prototypes with DB 600 engines were produced as the Do 17R-0, but did not enter production.
When the Soviet Polikarpov I-16 monoplane arrived over Spain where the Do 17P's were being tested, the woeful armament clearly needed an upgrade. A completely new pod-like cockpit was designed for the plane to give the crew more room and better visibility. The roof was extended upward over the line of the fuselage, sloping down to meet it just in front of the wing. The dorsal gun was moved to the rear of the pod where it had a considerably better field of fire. Likewise, the floor was dropped under the fuselage and the ventral gun moved to the back of the pod, allowing it to fire directly to the rear. The changes in the roof and floor made the whole front of the plane much larger. The aircraft now looked much more like the Junkers Ju 88 than previous models, and was no longer referred to as the flying pencil.
Three prototypes with the DB 600 were constructed as the Do 17S-0 reconnaissance versions, but did not go into production. An additional fifteen Do 17U-1 pathfinder models were built, similar to the S but adding an additional crewman (to five) to operate the complex radio equipment. The U models were to fly in ahead of other bombers on night missions, using the radio equipment to locate the target and drop flares on it. They were personally requested by KG 100 as experimental models for this role.
At first, the plane could use its 265mph maximum speed to stay away from biplane fighters, and its light armament was almost enough for the later planes it met in Spain. But by the time it met British planes, notably over England during the Battle of Britain, it was hopelessly outclassed, typically eight guns to one. It could still sometimes outrun the Hurricanes in a slight dive, but since the Fafnir engine was good only at low altitudes they instead switched terrain-following mass raids which worked fairly well. Even then the Do 17's were butchered over England; for all the trouble spent developing the Do 17, the Luftwaffe was better off without it. Production ended in 1940 and the surviving planes were handed off to allied nations over the next two years.
Do 17Z-10 |
The Spanner IR detector is visible in the window |
After bomber production ended in 1940, the Z model was modified with a "solid" nose from the Ju 88C and fitted with one 20mm and three 7.92mm MG15's to be used as night fighters. One prototype was constructed as the Z-6 Kauz I (screech-owl), and then the design was futher modified with a custom nose with four 7.92 mm MG17 machine guns and four 20 mm MG-FF cannon. Only nine of these Do 17K-10 Kauz II designs were built, fitted with both a Lichtenstein C1 radar and the Spanner-II infra-red detection systen. The later proved to be essentially useless, and was not used on later night fighter designs.
The Z-10 served for two years in the night fighter role, where they were used in Josef Kammhuber's defensive system known as the Kammhuber Line. Each fighter was assigned a single "cell", with three strips of such cells running from Denmark to the middle of France. Within each cell a direction center on the ground tracked both the Kauz and a single target, guiding them until the target was visible in the Spanner. RAF Bomber Command were able to ascertain the nature of the line, and sent all of their bombers in a single "stream", thus overwhelming the defenses. The Z-10s were then replaced with more capable planes mounting their own radars.
Do 215 |
Eighteen Do 215A-1 were built for export to Sweden in 1939, but were embargoed and instead put into service with the Luftwaffe as the Do 215B-1 and Do 215B-2. Two aircraft were sent to the Soviet Union as Do 215B-3s, otherwise unchanged. The Do 215B-4 was a reconnaissance aircraft similar to the Z-3. The Do 215B-5 Kauz III was a night fighter, similar to the Do 17Z-10. In total another 101 planes were completed as Do 215's.