Dornier Do 217

https://en.wikipedia.org/wiki/Dornier_Do_217

The Dornier Do 217 was a bomber used by the German Luftwaffe during World War II
as a more powerful development of the Dornier Do 17, known as the Fliegender
Bleistift (German: "flying pencil"). Designed in 1937 and 1938 as a heavy bomber
but not meant to be capable of the longer-range missions envisioned for the
larger Heinkel He 177, the Do 217's design was refined during 1939 and
production began in late 1940. It entered service in early 1941 and by the
beginning of 1942 was available in significant numbers.

The Dornier Do 217 had a much larger bomb load capacity and had much greater
range than the Do 17. In later variants, dive bombing and maritime strike
capabilities using glide bombs were experimented with, considerable success
being achieved. Early Do 217 variants were more powerful than the contemporary
Heinkel He 111 and Junkers Ju 88, having a greater speed, range and bomb load.
Owing to this it was called a heavy bomber rather than a medium bomber. The Do
217 served on all fronts in all roles. On the Eastern Front and Western Front it
operated as a strategic bomber, torpedo bomber and reconnaissance aircraft. It
also performed tactical operations, either direct ground assault or
anti-shipping strikes during the Battle of the Atlantic and Battle of Normandy.
The Do 217 was also converted to become a night fighter and saw considerable
action in the Defence of the Reich campaign until late in the war.

The type also served in anti-shipping units in the Mediterranean, attacking
Allied convoys and naval units during the Battle of the Mediterranean. In 1943,
the Do 217 was the first aircraft to deploy a precision-guided munition in
combat, when a Fritz-X radio-guided bomb sank of the Italian battleship Roma in
the Mediterranean. After the end of the war, at least one Dornier Do 217
continued in military operational service with the Swiss Air Force until 1946.


Role
Medium bomber
Heavy bomber
Night fighter
Reconnaissance aircraft

Manufacturer
Dornier Flugzeugwerke

First flight
4 October 1938

Introduction
1941

Retired
1945

Primary user
Luftwaffe

Produced
1940–1943

Number built
1,925

Developed from
Dornier Do 17

Developed into
Dornier Do 317

Flying the Do 217 M-1

In October 1945 British Captain Eric Brown undertook full handling trials with a
Do 217 M-1 WNr 56158 at RAF Farnborough. He recalled a distinctly
"underwhelming" experience. Brown recalled that he took off with full power of
some 2,700 rpm and the lightly loaded Do 217M left the runway at 160 km/h (99
mph). Brown held a shallow climb, waiting to reach 200 km/h (120 mph) before
retracting the undercarriage. Brown timed the time it took to retract, which was
between 30 and 40 seconds. At 150 m (490 ft) he reduced power to 2,500 rpm and
raised the flaps at about 230 km/h (140 mph). With the flaps up a climbing speed
of 230 km/h (140 mph) was established giving a rate of "very moderate
proportions".

While in cruising mode, Brown took the Dornier to 5,500 m (18,000 ft) and with
the tail at +2 degrees angle of incidence, gave it a top speed of 523 km/h (325
mph), true air speed. Brown stated the aircraft was very stable about all three
axes, and the controls were well harmonised and effective, and not unduly heavy
for bomber operations. At the other end of the speed range, stall occurred at
154 km/h (96 mph), and was characterised by a gentle nose-down pitch. At this
stage Brown tried the Dornier's single-engine performance and this "proved
decidedly unimpressive". It underlined that the aircraft was underpowered. Above
1,500 m (4,900 ft), height could not be maintained at 2,300 rpm and its ceiling
was barely 7,600 m (24,900 ft). Brown reverted to "normal power", and decided to
"chance his arm" (risk) on a dive-bombing procedure in what he described as a
"ponderous aeroplane". Brown made a straight dive to 700 km/h (430 mph), the
maximum permitted below 3,000 m (9,800 ft) in order to get a feel for the
controls, which began to stiffen considerably. The engine revolutions built to
2,750 during the dive causing a lot of noise. Brown pulled the aircraft out of
its dive though it called for a "good full-blooded heave" on the control column.

After climbing to regain the height lost, Brown decided to test the
tail-mounted, clamshell-like dive brake and automatic pull-out equipment. The
Dornier entered the dive automatically when the dive switch was selected and
soon attained its "braked condition", limiting the airspeed to 575 km/h (357
mph). The pull-out was initiated by hitting the bomb-release stick on the
control column or selecting the "level flight" switch, which also retracted the
dive-brake. Brown stated, "All very sedate and totally unimpressive as a
precision weapon".

The landing procedure began at an air speed of 250 km/h (160 mph). The oil
coolers were opened fully and the radiator hatches opened to 30 degrees. At 240
km/h (150 mph) the undercarriage was lowered, which again took 30 to 40 seconds.
Flaps were lowered to their start position at 235 km/h (146 mph) and fully
deployed at 220 km/h (140 mph). The tail had to be trimmed to 4 degrees
incidence (tail heavy). Final approach was made at 200 km/h (120 mph) and
touchdown occurred at about 160 km/h (99 mph). Landing weight was roughly 13,000
kg (29,000 lb). The control column had to be held back beyond the neutral to
keep the tail wheel locked until the landing run was complete.

The first deliveries of Do 217s to operational units of the Luftwaffe was the
pre-production Do 217A-0 reconnaissance aircraft, which entered service with the
Aufklärungsgruppe der Oberfehlshaber der Luftwaffe to carry out clandestine
reconnaissance missions over the Soviet Union. Deliveries of the Do 217E started
late in 1940, with some aircraft joining another reconnaissance unit, 2 Staffel
of Fernaufklärungsgruppe 11, which was also involved in spyflights over the
Soviet Union from bases in Romania.

Specifications (Do 217M-1)

General characteristics
Crew: 4
Length: 17 m (55 ft 9 in)
Wingspan: 19 m (62 ft 4 in)
Height: 4.97 m (16 ft 4 in)
Wing area: 57 m2 (610 sq ft)
Empty weight: 9,065 kg (19,985 lb)

Empty equipped weight:10,950 kg (24,140 lb)
Max takeoff weight: 16,700 kg (36,817 lb)
Fuel capacity: 2,960 l (780 US gal; 650 imp gal) in fuselage tank and four wing
tanks
Powerplant: 2 × Daimler-Benz DB 603A V-12 inverted liquid-cooled piston engines
for take-off
1,379 kW (1,849 hp) at 2,100 m (6,900 ft)Propellers: 3-bladed VDM constant-speed
propellers

Performance
Maximum speed: 475 km (295 mph, 256 kn) at sea level
560 km/h (350 mph; 300 kn) at 5,700 m (18,700 ft)Cruise speed: 400 km (250 mph,
220 kn) at optimum altitude
Range: 2,180 km (1,350 mi, 1,180 nmi) with maximum internal fuel
Ferry range: 2,500 km (1,600 mi, 1,300 nmi) with auxiliary fuel tank
Service ceiling: 9,500 m (31,200 ft) without bomb load
7,370 m (24,180 ft) with maximum internal bomb loadRate of climb: 3.5 m/s (690
ft/min)
Time to altitude: 1,000 m (3,300 ft) in 3 minutes 18 seconds
2,000 m (6,600 ft) in 6 minutes 42 seconds
Armament

Guns:

2x 7.7 mm (0.303 in) MG 81 machine gun with 500 rpg in the nose
2x 7.7 mm (0.303 in) MG 81 machine gun with 750 rpg in lateral positions
1x 13 mm (0.512 in) MG 131 machine gun with 500 rounds in ventral step
1x 13 mm (0.512 in) MG 131 machine gun with 500 rounds in
Bombs: maximum bomb load 4,000 kg (8,800 lb) (2,520 kg (5,560 lb) internally)





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