Dornier Do 217

The Dornier Do 217 was Germany’s most versatile medium bomber of the Second World War, a twin-engined aircraft that served as a level bomber, a night fighter, a reconnaissance aircraft, and a carrier for guided missiles, including the Fritz X bomb that sank the Italian battleship Roma. With about 1,900 built between 1940 and 1944, the Do 217 fought over Britain, the Atlantic, and the Mediterranean, and it remained in service until the end of the war.

1. Key Facts

Field	Value
Type	Twin-engined medium bomber (also night fighter and reconnaissance)
Country	Germany
Service period	1940–1945
Production	About 1,900 built
Length	17.0 metres (55.8 feet)
Wingspan	19.0 metres (62.3 feet)
Height	4.97 metres (16.3 feet)
Crew	4 (pilot, observer/bomb aimer, radio operator, gunner)
Engine	2 × BMW 801D radial, 1,700 horsepower each
Speed	557 km/h (346 mph) at 5,700 metres
Range	About 2,145 km (1,333 miles)
Service ceiling	9,500 metres (31,170 feet)
Main armament	Up to 4,000 kg of bombs; Fritz X and Hs 293 guided missiles
Defensive armament	Up to 6 × 7.92 mm MG 81 and 13 mm MG 131 machine guns
Main theatres	Battle of Britain; Atlantic; Mediterranean; Defence of the Reich

2. Development and Design

From the Do 17 to the Do 217

The Dornier Do 217 was developed from the earlier Dornier Do 17, the fast light bomber known as the Flying Pencil, which had served in the Spanish Civil War and in the early months of the Second World War. The Do 17 was fast but it carried only a small bomb load, and the Luftwaffe wanted a larger bomber with a greater payload and a longer range, so Dornier designed the Do 217, which was larger, heavier, and more powerful, with two BMW 801 engines and a bomb bay that could carry up to 4,000 kilograms of bombs. The prototype first flew in August 1938, and production began in 1940, with the first aircraft delivered to bomber units in late 1940, in time for the Blitz on Britain.

A Larger, More Capable Bomber

The Do 217 was a significant improvement on the Do 17, with a larger fuselage, a stronger wing, and more powerful engines, and it could carry twice the bomb load over a longer range. The aircraft had a stepped cockpit, with the pilot and the observer sitting in a glazed nose, and a defensive armament of machine guns in the nose, in the dorsal turret, and in the ventral position, which gave it all-round defence. The Do 217 was also fitted with a radio and with navigation equipment, and later versions were fitted with radar for night fighting and for anti-shipping operations. The aircraft was well built and reliable, and it was popular with its crews, who appreciated its handling and its performance.

Production and Manufacturers

Production of the Do 217 was carried out by Dornier at Friedrichshafen and at Munich, with about 1,900 aircraft built between 1940 and 1944, in a variety of versions for bombing, reconnaissance, and night fighting. Production was slowed by Allied bombing and by shortages of materials, and the Do 217 was never built in the numbers that the Luftwaffe wanted, but it was produced in sufficient quantities to equip several bomber wings and night fighter units. The aircraft was also used by the Italian Air Force, which received a small number of Do 217s, although these saw little combat.

3. Technical Specifications

The BMW 801 Engines

The Do 217 was powered by two BMW 801D fourteen-cylinder radial engines, each producing 1,700 horsepower, which gave the aircraft a top speed of 557 kilometres per hour at 5,700 metres, a range of about 2,145 kilometres, and a service ceiling of 9,500 metres. The BMW 801 was a reliable and powerful engine, used in the Focke-Wulf Fw 190 fighter as well as in the Do 217, and it was fitted with a fan for cooling, which improved its performance at high altitude. The engines were mounted in nacelles under the wings, and they drove three-bladed propellers, which gave the aircraft a good rate of climb and a stable flight.

Bomb Load and Guided Missiles

The Do 217 could carry up to 4,000 kilograms of bombs in its internal bomb bay and on external racks, including high-explosive bombs, incendiary bombs, and mines, and it was used for level bombing, for dive bombing, and for anti-shipping attacks. The aircraft was also the main carrier for the Fritz X radio-controlled glide bomb and the Henschel Hs 293 rocket-powered glide bomb, which were guided by the bombardier using a radio link, and which were used to attack Allied shipping in the Mediterranean. The Fritz X, in particular, was a formidable weapon, with a 1,400-kilogram warhead that could penetrate the deck armour of a battleship, as the sinking of Roma showed.

Defensive Armament and Crew

The Do 217 had a crew of four, a pilot, an observer who also served as bomb aimer, a radio operator, and a gunner, who worked in a cramped but well-organised cockpit and fighting compartment. Defensive armament consisted of up to six machine guns, including 7.92 mm MG 81 guns in the nose and in the ventral position, and 13 mm MG 131 guns in the dorsal turret, which gave the aircraft defence against fighters attacking from any direction. Later versions were fitted with a 20 mm cannon in the nose, and with radar for night fighting, which allowed the aircraft to find and attack bombers in the dark.

4. Combat Service

The Blitz and the Battle of Britain

The Do 217 first saw combat in late 1940, during the Blitz on Britain, where it was used to bomb London and other British cities, and where it proved to be a capable bomber, with a good bomb load and a high speed that made it difficult for British fighters to intercept. The aircraft also served in the Baedeker raids of 1942, when German bombers attacked British cathedral cities in retaliation for the bombing of Lübeck, and it continued to serve in the night bombing of Britain until 1944, when the Luftwaffe’s bomber force was withdrawn to defend Germany.

The Atlantic and the Mediterranean

The Do 217 was also used in the Battle of the Atlantic, where it was fitted with radar and used to attack Allied convoys, and in the Mediterranean, where it was used to attack Allied shipping and to support German forces in North Africa and Italy. The most famous Do 217 operation was the attack on the Italian fleet on 9 September 1943, when Do 217s of Kampfgeschwader 100, carrying Fritz X glide bombs, sank the battleship Roma and damaged her sister ship Italia, in one of the first successful uses of a guided missile in warfare. The Do 217 also attacked Allied shipping at Salerno and at Anzio, where it sank and damaged several ships with Hs 293 missiles.

Night Fighter and Reconnaissance Service

Later in the war, the Do 217 was used as a night fighter, fitted with radar and with forward-firing cannon, and it served in the defence of Germany against RAF Bomber Command, shooting down a number of British bombers. The aircraft was also used for reconnaissance, with cameras fitted in the bomb bay, and for electronic warfare, jamming British radar and radio. The Do 217 was a versatile aircraft, and it served in many roles, although by 1944, it was becoming obsolete, and production ended in 1944, with the remaining aircraft serving until the end of the war.

5. Variants

The Bomber Versions

The Do 217 was produced in many variants, with the main bomber versions being the Do 217E, with BMW 801 engines, the Do 217K, with a redesigned nose and improved defensive armament, and the Do 217M, with Daimler-Benz DB 603 engines, which gave better performance at high altitude. The Do 217E was the first production version, and it served in the Blitz and in the Mediterranean, while the Do 217K and Do 217M were later versions with improved equipment and armament.

Night Fighter and Specialised Versions

The night fighter versions, designated Do 217J and Do 217N, were fitted with radar and with cannon armament, and they served in the night defence of Germany, where they were effective against RAF bombers. There were also reconnaissance versions, designated Do 217P and Do 217R, with cameras and with high-altitude engines, and a torpedo bomber version, which was tested but not produced in large numbers. The Do 217 was also used as a test aircraft for new weapons, including the Fritz X and the Hs 293, and for new engines and equipment.

The Do 217 in Italian Service

A small number of Do 217s were supplied to the Italian Air Force, which used them for bombing and for reconnaissance, although they saw little combat and were withdrawn after Italy’s surrender in 1943. The Do 217 was also considered for export to other countries, but the war ended before any export orders could be fulfilled. The Italian Air Force received a small number of Do 217J night fighters in 1943, but the aircraft were difficult to maintain without German spare parts, and they were abandoned after the armistice, when their crews flew them to Allied airfields or destroyed them on the ground.

6. Strengths

Versatility and Bomb Load

The great strength of the Do 217 was its versatility, for it could serve as a bomber, a night fighter, a reconnaissance aircraft, and a guided-missile carrier, and it did so effectively in all these roles. The aircraft’s bomb load of 4,000 kilograms was large for a medium bomber, and its range of 2,145 kilometres allowed it to operate over Britain, the Atlantic, and the Mediterranean. The Do 217 was a useful aircraft for the Luftwaffe, which needed a versatile bomber that could be adapted to new roles as the war changed.

Speed and Handling

The Do 217 was fast for a bomber, with a top speed of 557 kilometres per hour, which made it difficult for fighters to intercept, and it was well built and reliable, with a good rate of climb and a stable flight. The aircraft was popular with its crews, who appreciated its handling and its performance, and it was regarded as one of the best German bombers of the war, although it was never built in sufficient numbers to make a decisive difference.

The Guided Missile Carrier

The Do 217’s role as a carrier for the Fritz X and Hs 293 guided missiles was a significant strength, for these weapons allowed the aircraft to attack ships from outside the range of anti-aircraft guns, and to sink or damage ships that conventional bombs could not touch. The sinking of Roma by a Fritz X dropped from a Do 217 was a landmark in naval warfare, and it showed the potential of guided missiles, which would become a major weapon in the post-war period.

7. Weaknesses

Vulnerability to Fighters

The main weakness of the Do 217 was its vulnerability to fighters, for although it was fast for a bomber, it was slower than Allied fighters, and its defensive armament of machine guns was inadequate against cannon-armed fighters. The aircraft suffered heavy losses to British and American fighters, particularly in daylight operations, and it was eventually withdrawn from daylight bombing and used only at night, where it was safer but less accurate. The Luftwaffe tried to solve the problem by turning the Do 217 into a night fighter, producing the Do 217J and Do 217N variants fitted with Lichtenstein radar and a solid nose armed with cannon, but only about 370 of these were built and they were too slow to catch the fast British Mosquito night fighters. The type found its most notable success not as a bomber but as a carrier of guided weapons: Do 217s of Kampfgeschwader 100 dropped Fritz X radio-guided bombs that sank the Italian battleship Roma on 9 September 1943, killing about 1,393 of her crew, and damaged the battleship Italia and the cruiser USS Savannah. Even so, the fighter threat remained the type’s greatest weakness, and by 1944 most surviving Do 217s had been withdrawn from front-line service.

Limited Production and Obsolescence

The Do 217 was never built in sufficient numbers, with only about 1,900 produced, compared with more than 6,000 Heinkel He 111s and more than 15,000 Junkers Ju 88s, and it was therefore unable to equip more than a few bomber wings. The aircraft also became obsolete by 1944, as Allied fighters became faster and better armed, and as the Luftwaffe’s bomber force was reduced to a shadow of its former self. The Do 217 was a good aircraft, but it arrived too late and in too few numbers to change the course of the war.

Complexity and Maintenance

The Do 217 was a complex aircraft, with two powerful engines, a sophisticated bomb sight, and, in later versions, radar and guided-missile equipment, which required skilled maintenance and which was difficult to keep serviceable in the field. The aircraft’s complexity also made it expensive to build, and production was slowed by shortages of materials and by Allied bombing, which disrupted the factories that built it. Ground crews needed specialist tools and training to service the BMW 801 engines and the radar sets, and as the war went on, the lack of trained mechanics and of spare parts kept many Do 217s grounded, even when fuel was available.

8. Comparison with Rivals

Against the Junkers Ju 88 and Heinkel He 111

Compared with the Ju 88, the Do 217 was larger and carried a heavier bomb load, but it was slower and less manoeuvrable, and the Ju 88 was produced in far greater numbers and was more versatile. Compared with the He 111, the Do 217 was faster, better armed, and more modern, with a higher speed and a greater bomb load, although the He 111 was more numerous and had a longer service history. The Do 217 was a better bomber than the He 111, but it was not as widely used as the Ju 88, which was the Luftwaffe’s standard bomber.

Against British and American Bombers

Against British bombers such as the Wellington and the Halifax, the Do 217 was comparable in bomb load and in speed, although the British bombers were produced in greater numbers and had better defensive armament. Against American bombers such as the B-17 and the B-24, the Do 217 was smaller and carried a lighter bomb load, but it was faster and more manoeuvrable, and it was designed for a different role, as a medium bomber rather than a heavy bomber. The Do 217 was a capable medium bomber, but it could not match the heavy bombers of the Allies in payload or in range.

Against the Night Fighter Role

As a night fighter, the Do 217 compared well with the Messerschmitt Bf 110, which was the Luftwaffe’s standard night fighter, although the Bf 110 was faster and more heavily armed. The Do 217 was, however, a larger aircraft, with more room for radar and for crew, and it was effective in the night fighter role, shooting down a number of RAF bombers. The Do 217 was eventually replaced by more capable night fighters, such as the Ju 88G and the Heinkel He 219, which were faster and better equipped.

9. Legacy

The Guided Missile Pioneer

The legacy of the Dornier Do 217 is its role as a pioneer of guided missile warfare, for it was the aircraft that carried the Fritz X bomb that sank Roma, the first battleship to be sunk by a guided missile, and it showed the world that the missile was the weapon of the future. The Do 217 is remembered as a versatile and capable bomber, and as a symbol of German engineering, although it is less well known than the Ju 88 or the He 111, with which it served.

A Versatile Bomber Remembered

The Do 217 is preserved in museums, including the Royal Air Force Museum at Hendon, where a Do 217 is displayed, and it is remembered by historians as one of the best German bombers of the war, a versatile aircraft that served in many roles and that played a part in the development of guided weapons. The aircraft’s story is a reminder that versatility and adaptability are valuable qualities in a military aircraft, and that a good design can serve in roles its designers never imagined.

Remembering the Do 217 Crews

The crews of the Do 217 are remembered for their skill and their courage, for flying a bomber over Britain, the Atlantic, and the Mediterranean, often at night and often against heavy defences, and for doing so with determination. The Do 217 crews, many of whom were lost, deserve to be remembered alongside the crews of the Ju 88 and the He 111, for they too fought in the air war, and they too paid the price. Kampfgeschwader 100, the wing that sank Roma, lost many of its crews over the Mediterranean and the Atlantic, and its veterans remember the Do 217 as a demanding but capable aircraft that deserved a better fate than the one it received.

Frequently Asked Questions

How many Dornier Do 217s were built?
About 1,900 Do 217s were built between 1940 and 1944, in a variety of versions for bombing, night fighting, and reconnaissance.

What was the main role of the Do 217?
The Do 217 was a medium bomber, used for level bombing, for anti-shipping attacks, and for night bombing, and it also served as a night fighter and as a carrier for guided missiles.

How did the Do 217 sink the Italian battleship Roma?
On 9 September 1943, Do 217s of Kampfgeschwader 100, carrying Fritz X radio-controlled glide bombs, hit Roma with two bombs, which penetrated her decks and detonated her magazines, sinking the ship with the loss of 1,393 men.

What was the top speed of the Do 217?
The Do 217 had a top speed of 557 km/h (346 mph) at 5,700 metres, with a range of about 2,145 km and a service ceiling of 9,500 metres.

Did the Do 217 serve as a night fighter?
Yes, Do 217J and Do 217N night fighter versions, fitted with radar and cannon, served in the defence of Germany against RAF Bomber Command, shooting down a number of British bombers.

Are any Do 217s still in existence?
Yes, a Do 217 is preserved at the Royal Air Force Museum in Hendon, London, and parts of other aircraft survive in museums in Germany and the United States.

Sources

• William Green, Warplanes of the Third Reich (1970)
• Manfred Griehl, Dornier Do 217 (Airlife, 1998)
• The Royal Air Force Museum, Hendon, Do 217 collection
• Chris Goss, The Dornier Do 217 (2015)
• The Imperial War Museum, Luftwaffe bomber collection