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Dornier Do-217

 

The Do 217 was one of the few completely new bombers to enter service with the Luftwaffe after the start of the Second World War. Though similar in config-uration to the much earlier Do 17 series, it had a totally different structure and was much larger and more powerful. Like the contemporary Fw 190, the Do 217 was an all-electric aircraft.

The first prototype, the Do 217 VI, first flew in August 1938. Developed from the basic Do 17 design but was stressed for heavier loads and had a dive brake fitted in the tail which opened out like an umbrella when the aircraft was used as a dive-bomber but, with two 1150-hp DB 601 engines, was underpowered. Several prototypes followed, with the Jumo 211 of similar power, until the V7 of 1939 found more power with two of the 1550-hp BMW 139 radials. The Do 217 V7 abandoned the dive brake fitted in the V1 which had rarely been used since the bomber was better suited for level attacks than dive-bombing. This engine was not put into production and the Do 217 changed to the heavier but more powerful BMW 801, rated at 1600 hp. Dornier had prolonged difficulties in achieving acceptable flying qualities and clearing the Do 217 for level and dive bombing, torpedo dropping, minelaying and later, reconnaissance, ground attack, anti-shipping strike and night fighting. The problem of poor handling was partially solved by the addition of fixed slots along the leading edges of the twin fins.

The first production version was the Do 217E, which was powered by two BMW 801A engines and armed with one fixed MG 151 and one flexible MG 151 machine-gun in the nose; one MG 131 in a manually operated dorsal turret; one MG 131 in a lower rear-firing position; and two MG 15s in lateral-firing positions.

 

In most versions a crew of four was accommodated, close together but in fair comfort, in the nose compartment. The wing had hot-air de-icing and accommodated flexible fuel cells between the spars, which passed through the top of the fuselage above the extremely large bomb bay. Early sub-types had a unique petal-type dive-bombing airbrake forming a long tailcone, but this was fairly soon abandoned.

The E-2 sub-version was similar but had an electrically operated turret, while the E-5 had attachments under the outer wings for two Hs 293 glider bombs for attacking convoys - special equipment for controlling these bombs was installed in the fuselage. Various armament schemes were fitted to prototypes and the E-0 and E-1, but the first major sub-type, the E-2, had a fixed MG 151/15 forward-firing cannon, an MG 131 in the dorsal turret, an MG 131 aimed manually from the lower rear and two to four 7.92-mm (0.312-in) MG 15 aimed from nose and beam windows. The Do 217E-2 was initially intended as a dive-bomber and was fitted with an umbrella dive brake, and carried a 1000 kg (2200 lb) bombload.

Subsequent bomber versions had MG 81 machine-guns in place of the MG 15, often in neat pairs; the R19 Rfistsatze pack (field-modification kit) added four MG 81 firing aft in the tail. The bombload was typically 4000 kg (8818 lb), including about 1500 kg (3307 lb) hung externally. Most versions had a bomb bay long enough to accommodate two torpedoes internally. All early versions had 1580-hp BMW 801A or 801M engines with fan cooling and multiple fishtail exhausts.

A handful of E-0, E- 1 and E-2 versions saw action over Britain in 1940-41, mainly with KG 40. The impressive capability of the 217 was marred by the structural and control hazards attendant upon steep dive-bombing, and this technique was soon erased from the 217's repertoire. The elimination of this role tended to accentuate the importance of the work already in hand in early 1941 for the development of air-launched guided missiles for use against ships and similar important targets.

A Dornier Do 217E-4 was equipped with a Gerat 104 (104 device), prewar experimental design for an airborne anti-shipping gun. It was a recoilless gun firing a 635-kg (1400-lb) armour-piercing shell. The gun was slung in the bomb bay and could be swung out when the Do 217 went into an attack.

The Dornier Do 217E-5 was the final production model of the E series and was designed to carry the Henschel Hs 293 rocket-powered radio-controlled glide bomb on pylons outboard of the engine nacelles. Do 217E-5s saw action with the Luftwaffe in the Mediterranean against the Royal Navy, US Navy and co-belligerent Italian warships.

The first missile to reach operational service was the Henschel Hs 293, weighing 1045 kg (2304 lb), which became operational with 11/KG 100 based at Cognac in August 1943.The Henschel missile was carried, two at a time, by the Do 217E-5, which was otherwise changed only by addition of the radio guidance equipment. Two days after the introduction of the missile, 11/KG 100 attacked and sank the corvette HMS Egret. Substantial numbers of E-series bombers served on the Eastern Front from 1942, while the only Do 217 Geschwader(wing) to remain in the West, Kg 2, lost 65 of its original 88 crews between May and September of that year in sporadic missions against Britain.

The Do 217K V1, the prototype of the K series which was flown with a single fin and rudder assembly. The K1 had an R25 tail housing to take the Perlon braking parachute which became a standard feature in later models. Though intended as a night bomber the K series could carry four L5 torpedoes or FX 1400 Fritz X stand-off glider bombs. With the Do 217K-1 a more capacious crew compartment was introduced, being a redesigned deeper and more rounded nose. Most of this series had the 1700-hp BMW 8011), and the extra power enabled the wing of the K-2 version to be extended to 24.8 m (81 ft 41 in) to lift two of the formidable 1567-kg (3455-lb) FX- 1400 radio-controlled free-fall missiles on racks under the inner wings. The K was the fitting of a battery of four fixed rearward-firing MG 81 machine-guns in the tail-cone. Major Bern-hard Jope's III/KG 100 became operational with the FX missile on the Do 217K-2 in the late summer of 1943. They worked up at Graz, moved to Istres (Marseilles) and were ready when the Italian fleet sailed from La Spezia to join the Allies on September 9, 1943. Six K-2s sank the flagship, Roma, which went down with all 1255 men, and crippled Italia. Later Jope himself hit HMS Warspite and his unit sank or damaged other Allied ships during the Salerno landings.

The Do 217J was a somewhat hastily contrived night fighter, some being rebuilt 'E' -series bombers with heavy nose armament and with light bombs in the rear bomb bay. The J-2 had Lichtenstein FuG 202 (some-times and/or FuG 212) airborne radar, with a different arrangement of guns and the bomb bay filled with ammunition. The Do 217J-2 had a solid nose mounting four 20mm MG FF cannon, four 7.92mm MG 17 machine-guns. The upper and lower rear guns of the E-2 were retained. Most of the 'J-’ series were passed to the Italian Regia Aeronautica (later Aviazione della RSI, after the September 1943 armistice) to help defend Milan and Turin by night.

 

A modest production run of Do 217M bombers in 1943 had the 1750-hp DB 603A engine, while a nightfighter conversion of this model was the 217N. Some of the N-series, such as the N-2/R22, had four MG 151 cannon firing steeply upwards at an angle usually near 70' in the so-called 'Schrdge Musile' scheme.

 

Dornier 217M-1

 

 

The Do 217P was planned as a high-altitude reconnaissance bomber with pressurized cabin for the crew of four and two DB 603B engines fed with boosted mixture by a vast supercharger in the fuselage driven by a DB 605T. The Do 217P-O was a high altitude reconnaissance aircraft, though it could carry two 500-kg (1100-lb) bombs on underwing racks or two 900-litre (198-Imp gal) auxiliary tanks. It carried one Rb 20/30 camera and two Rb 75/30 as a reconnaissance aircraft, but a minimum of defensive armament principally because it flew out of range of enemy fighters. Although the P looked knobbly and bristled with engine inlets, radiators and intercoolers, it could fly at over 15 240 m (50 000 ft) and exceed 585 km/h (363 mph). The remaining 217P development aircraft were stripped of their pressurization and put into service as Do 217R missile carriers armed with the Hs 293. First flown in June 1942, this version failed to enter production.

Total production of the Do 217 was only 1905. Of these, 1541 were offensive, the other 364 being night fighters.

 

Gallery

 

Do 217 E
Engines: 2 x BMW 801
Span: 19 m (62 ft 4 in)

Do 217 E-2
Engines: 2 x BMW 801
Span: 19 m (62 ft 4 in)
Gross weight: 15000 kg (33069 lb)
Maximum speed: 515 km/h (320 mph)

Do 217 J
Engines: 2 x BMW 801
Span: 19 m (62 ft 4 in)

Do 217 K
Engines: 2 x BMW 801
Span: 19 m (62 ft 4 in)

Do 217 K-2
Engines: 2 x BMW 801

Do 217 M
Engines: 2 x Daimler-Benz DB 603
Span: 19 m (62 ft 4 in)

 

Do 217N
Prop: four blade
Wingspan: 62 ft 4 in
Length: 58 ft 9 in
Speed: 320 mph at 18,700 ft
Ceiling: 31,170 ft
Range: 1550 miles
Armament: 4 x 20mm cannon, 4 x 7.9mm mg, 1 x 13mm mg
Crew: 3