Dornier Do 17

https://en.wikipedia.org/wiki/Dornier_Do_17

The Dornier Do 17, sometimes referred to as the Fliegender Bleistift ("flying
pencil"), is a light bomber of Nazi Germany during World War II. It was produced
by Claudius Dornier's company, Dornier Flugzeugwerke. The aircraft was designed
as a Schnellbomber ("fast bomber"), a light bomber which, in theory, would be so
fast that it could outrun defending fighter aircraft.

The Dornier was designed with two engines mounted on a "shoulder wing" structure
and possessed a twin tail fin configuration. The type was popular among its
crews due to its handling, especially at low altitude, which made the Do 17
harder to hit than other German bombers.

Designed in the early 1930s, it was one of the three main Luftwaffe bomber types
used in the first three years of the war. The Do 17 made its combat debut in
1937 during the Spanish Civil War, operating in the Condor Legion in various
roles. Along with the Heinkel He 111 it was the main bomber type of the German
air arm in 1939–1940. The Dornier was used throughout the early war, and saw
action in significant numbers in every major campaign theatre as a front line
aircraft until the end of 1941, when its effectiveness and usage was curtailed
as its bomb load and range were limited.

Production of the Dornier ended in mid-1940, in favour of the newer and more
powerful Junkers Ju 88. The successor of the Do 17 was the much more powerful
Dornier Do 217, which started to appear in strength in 1942. Even so, the Do 17
continued service in the Luftwaffe in various roles until the end of the war, as
a glider tug, research and trainer aircraft. A considerable number of surviving
examples were sent to other Axis nations as well as countries like Finland. Few
Dornier Do 17s survived the war and the last was scrapped in Finland in 1952.

On 3 September 2010, the Royal Air Force Museum London announced the discovery
of a Henschel-built Dornier Do 17Z buried in the Goodwin Sands off the coast of
Kent, England. On 10 June 2013, the salvage team raised the airframe from the
seabed.

The forward fuselage had a conventional stepped cockpit, with a fully glazed
nose. Early variants were labelled the "flying pencil" owing to its sleek and
continuous "stick-like" lines. As a result of the lessons learned in the Spanish
Civil War, the cockpit roof was raised and the lower, or bottom half, of the
crew compartment was a typical under-nose gondola or "Bodenlafette" (abbreviated
Bola): this inverted-casemate design ventral defensive armament position was a
common feature of most German medium bombers. The Bola was extended back to the
leading edge of the wings where the lower-rear gunners position and upper-rear
gunner position were level with each other. As with contemporary German bombers,
the crew were concentrated in a single compartment. The cockpit layout consisted
of the pilot seat and front gunner in the forward part of the cockpit. The pilot
sat on the left side, close up to the Plexiglas windshield. One of the gunners
sat on the right seat, which was set further back to provide room for the 7.92
mm (0.312 in) MG 15 machine gun to be traversed in use. The Do 17 usually
carried a crew of four: the pilot, a bombardier and two gunners. The bomb-aimer
also manned the MG 15 in the nose glazing and Bola-housed rear lower position.
The two gunners operated the forward-firing MG 15 installed in the front
windshield, the two MGs located in the side windows (one each side) and the
rearward firing weapon. The cockpit offered a bright and panoramic view at high
altitude. The standard ammunition load was 3,300 rounds of 7.92 mm ammunition in
44 double-drum magazines.

The wings were of a broad 55 m2 (590 sq ft) area and had a span of 18 m (59 ft
5/8 in) with a straight leading edge which curved in a near-perfect semicircle
into the trailing edge. The positions of the wing roots were offset. The leading
edge wing root merged with the top of the fuselage and cockpit. As the wing
extended backwards, by roughly two thirds, it declined downwards at a sharp
angle so that the trailing edge wing root ended nearly halfway down the side of
the fuselage increasing the angle of incidence. This design feature was used on
all future Dornier bomber designs, namely the Dornier Do 217. The trailing edge
was faired into the round fuselage shape. The engine nacelle was also faired
into the flaps. The extreme rear of the nacelle was hollow and allowed the flap
with an attached vertical slot to fit into the cavity when deployed.

The fuselage was 15.80 m (51 ft 10 in) long. It was thin and narrow, which
presented an enemy with a difficult target to hit. The fuselage had twin
vertical stabilizers to increase lateral stability. The power plant of the Z-1
was to have been the Daimler-Benz DB 601 but, owing to shortages from priority
allocation for Bf 109E and Bf 110 fighter production, it was allocated Bramo 323
A-1 power plants. The Bramos could only reach 352 km/h (219 mph) at 1,070 m
(3,510 ft). The limited performance of the Bramo 323s ensured the Do 17 could
not reach 416 km/h (258 mph) at 3,960 m (12,990 ft) in level flight when fully
loaded. The range of the Do 17Z-1 at ground level was 635 nmi (1,176 km); this
increased to 1,370 km (850 nm) at 4,700 m (15,400 ft). This gave an average
attack range of 400 nmi (740 km). The introduction of the Bramo 323P increased
the Z-2 performance slightly in all areas.

The Dornier had self-sealing fuel tanks to protect fuel stored in the wings and
fuselage. This reduced the loss of fuel and risk of fire when hit in action, and
often enabled the aircraft to return. Twenty oxygen bottles were provided for
crew use during long flights above 3,660 m (12,010 ft).


Role
Light bomber, night fighter and Reconnaissance aircraft

Manufacturer
Dornier Flugzeugwerke

First flight
23 November 1934

Introduction
1937

Retired
15 September 1952 (Finnish Air Force)

Primary users
Luftwaffe
Royal Yugoslav Air Force
Finnish Air Force
Spanish Air Force

Number built
2,139

Variants
Dornier Do 215

Despite its success, owing to shortages in the supply of the Daimler-Benz
engine, the production Do 17M was fitted with the Bramo 323 engine, with the
corresponding reconnaissance aircraft, the Do 17P, being powered by BMW 132Ns to
give better range.

The supply of the DB 600 remained extremely limited as production was soon
switched over to the fuel-injected DB 601, which was reserved for the
Messerschmitt Bf 109 and Messerschmitt Bf 110 fighters. Therefore, production
versions of the basic Do 17M model airframe were fitted with the new Bramo
323A-1 Fafnir engines of 670 kW (900 hp), which gave reasonable performance and
raised the bomb load to 1,000 kg (2,200 lb). The resulting Do 17 M-1 was
produced in small numbers and operated until 1941.

The prototypes for the M-1 series were Do 17M V1 (Werk Nr 691) and Do 17M V2
(Werk Nr 692) which were tested with bomb loads of a medium bomber. The third
prototype, Do 17M V3 was evaluated as a fast bomber. The M V1 was fitted with
two Daimler Benz DB 601 inline engines while the M V2 and M V3 had the Bramo 323
A and D respectively. The Ministry of Aviation favoured the widespread use of
the DB 601, but demand for the DB 601s in fighter aircraft and the lack of
production forced the use of the Bramo.

The Do 17 M-1 started its service as a medium bomber and was able to carry 2,200
lb (1,000 kg) of bombs. It was equipped with two air-cooled Bramo 323 A-1 or
A-2. The defensive armament consisted of two, and later three, MG 15 machine
guns. The first was operated in an A-Stand pod operated by the navigator through
the windshield. The position was allocated 370 rounds of ammunition. The
rearward firing B-Stand was operated by the radio operator and allocated 750
rounds. The rear position in the lower fuselage was allocated 375 rounds in a
C-Stand pod. The Do 17M could carry a bomb load of either 20 SC50 50 kg (110 lb)
or two SC250 250 kg (550 lb) bombs or 10 SC50 and a single SC250 bomb. The speed
of the M was superior to that of the E variant. The Do 17M could reach 420 km/h
(260 mph) at altitudes of 3,500 m (11,500 ft) and could achieve a maximum
service ceiling of 5,790 m (19,000 ft) and a range of 850 nautical miles (1,570
km).

After bomber production ended in 1940, the Z model was modified with a "solid"
nose from the Ju 88C, fitted with one 20 mm MG FF cannon and three 7.92 mm (.312
in) MG 17 machine guns, to be used as night fighters. Three prototypes were
converted from existing Z-series airframes to the Do 17 Z-7 Kauz I
("screech-owl") configuration. The standard Z-7 was fitted with Bramo 323P-1
radial engines and had a crew of three airmen. In comparison to the standard
bomber version, the fuel load arrangement was altered by subdividing into cells.
Two cells were in the wings, with a capacity of 770 litres (154 imperial
gallons) each. A third cell was placed in the bomb bay within the main fuselage,
having a capacity of 895 litres (179 imperial gallons). The oxygen supply for
the three man crew was reduced to nine bottles, as intercepts at high altitudes
were not anticipated. Add-on armour in the form of heavy steel plates was bolted
to the nose bulkhead to protect the crew against frontal fire. Originally, it
was planned to completely armour the crew compartment. This idea, was given up
again as the increased weight would have reduced flight performance of an
already slow aircraft. The ammunition loads for the three 7.92 mm MG 17s
amounted to 3,000 rounds and 400 rounds of ammunition for the 20 mm MG 151
cannon (although some Do 17Z bombers carried a single 20 mm for ground attack
missions).

Official figures state 2,139 Do 17s were built on German assembly lines. At the
Dornier factory at Oberpfaffenhofen, 328 Do 17Es were built along with a further
77 Do 17Fs and 200 Do 17M variants. Do 17Z production figures for
Oberpfaffenhofen stand at 420. At Friedrichshafen, 84 Do 17Ks were built, some
of which were sold to the Yugoslav Royal Air Force. Do 17P production was spread
out over different factory lines. At Siebel/Halle, eight were built. At the
Henschel factory at Berlin-Schönefeld 73 were constructed. At the HFB plant in
Hamburg 149 were built. Henschel also produced some 320 Do 17Zs, HFB contributed
to construction of 74 at its Hamburg plant, and another 73 were built at Siebel.
Some 105 examples of the Dornier Do 215B was later built at Oberpfaffenhofen.

By 19 September 1938, the Luftwaffe had received 579 Dornier Do 17s. These were
mostly Do 17E, F, M and P variants. During 1939–1940, some 475 Dornier Do 17Z
bombers, 16 reconnaissance aircraft and nine night fighters were built. Another
100 Dornier Do 215s, an updated variant of the Do 17, were built during this
period also.

Specifications (Do 17 Z-2)

General characteristics
Crew: 4
Length: 15.8 m (51 ft 10 in)
Wingspan: 18 m (59 ft 1 in)
Height: 4.56 m (15 ft 0 in)
Empty weight: 5,210 kg (11,486 lb)

Empty equipped: 5,888 to 5,963 kg (12,981 to 13,146 lb)
Max takeoff weight: 8,837 kg (19,482 lb)
Fuel capacity: standard fuel 1,540 l (339 imp gal), with aux tank in forward
bomb bay 2,435 l (536 imp gal)
Powerplant: 2 × Bramo 323P 9-cyl. air-cooled radial piston engines with 1,000 PS
(986 hp, 736 kW) for take-off
Propellers: 3-bladed variable-pitch propellers

Performance
Maximum speed: 350 km/h (217 mph; 189 kn) at 8,040 kg (17,725 lb) at sea level

410 km/h (255 mph) at 8,040 kg (17,725 lb) at 5,000 m (16,404 ft)Cruise speed:
300 km/h (186 mph; 162 kn) at 8,837 kg (19,482 lb) at 4,000 m (13,123 ft)
Combat range: 660 km (410 mi; 356 nmi) with 1,540 l (339 imp gal) fuel and 1,000
kg (2,205 lb) of bombs

1,010 km (628 mi) with 2,435 l (536 imp gal) fuel and 500 kg (1,102 lb) of
bombsService ceiling: 8,200 m (26,900 ft)
Wing loading: 156 kg/m2 (32 lb/sq ft)
Power/mass: 0.170 kW/kg (0.11 hp/lb)

Armament

Guns: 6 × 7.92 mm (0.312 in) MG 15 machine guns in front, rear upper, rear lower
and cockpit side positions
Bombs: 1,000 kg (2,205 lb) of bombs carried internally, either 20 x 50 kg (110
lb) bombs or 4 x 250 kg (551 lb) bombs




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