Designed originally from an outline specification drawn up in July 1932 which referred to a “high-speed passenger transport and mailplane” as a six-passenger plane for Deutsche Luft Hansa’s European route network. From the outset the Do 17 was in fact a dedicated medium bomber and reconnaissance aircraft.

Dornier Do 17 Article

The first prototype, the Do 17c, shortly afterwards to be re-designated Do 17V1, was flown on 23 November 1934, powered by a pair of 660 hp BMW VI 12 cylinder liquid cooled V type engines, this having a single fin-and-rudder tail assembly whereas the second prototype, the Do 17 V2 (formerly Do 17a), was fitted with a twin fin-and-rudder assembly for comparison. The V2 flying on 18 May 1935.

Three prototypes were completed for DLH, each of them having a single fin and rudder; but their slimness was also their commercial undoing, the very narrow fuselage making it extremely difficult for passengers to reach their seats. Following its rejection by DLH, the Do 17 design languished for a time, until the RLM (Reichsluftfahrtministerium, or German aviation ministry), seeking a new medium bomber for the Luftwaffe, was persuaded to evaluate the Dornier aircraft for this role.

The RLM ordered further prototypes, beginning with the Do 17 V4, which flew in the late summer of 1935. These were generally similar to the first three prototypes, except for having twin fins and rudders (to make the aircraft a more stable bombing platform) and a decrease of 0.55 m (1 ft 9A in) in overall length. They carried a crew of three, and had an all metal fuselage, metal and fabric covered wings, and fully retractable mainwheels and tailwheel. All were broadly similar, except for the installation of 775 hp Hispano Suiza 12 Ybrs liquid cooled V type engines in the Do 17 V5 and a defensive armament of a single hand operated 7.9 mm (0.311 in) MG 15 machine gun in the cockpit of the Do 17 V7.

The Do 17 was a highly advanced design for the early 1930s, grouping all crew members in the forward fuselage and it was faster than virturally any single-seat fighter then existant. Preparations for the large-scale production of the Do 17 at Dornier’s Manzell, Allmansweiller and Löwenthal factories were underway by early 1938, when plans were also being fprmulated for additional productiom by Henschel at Berlin-Schönefeld, Siebel at Halle and by the Hamburger Flugzeugbau.

The first version to go into production, towards the end of 1936, was the Do 17E-1 bomber, based on the Do 17 V9, which had a further reduction of 0.90 m (2 ft 111 in) in the length of the nose. The Do 17E-1, powered by two 750 hp BMW VI 7.3 engines, carried a short range internal bombload of 750 kg (1653 lb) and had a defensive armament of two MG 15 machine guns, one above the fuselage and one below.

In parallel production was the Do 17F 1, a photographic reconnaissance counterpart to the E 1 with two cameras and an extra fuel tank installed in the bomb bay. Both versions were in squadron service with Luftwaffe units by the summer of 1937, the Do 17E-1 initially equipping the I. Gruppen of KG 153 and KG 155 while the F 1 went to the long-¬range reconnaissance group Fernatifklarungsgruppe 122. During 1937 38 the Do 17E and F were included among the types of Luftwaffe aircraft selected to equip units of the Condor Legion sent by Germany to fight on the Nationalist side in the Spanish Civil War. Here their performance made them virtually immune from interception by their opponents’ fighters.

The principal shortcomings of the Do 17 revealed over Spain were its limited warload and its poor defence against attack from below and to the rear, and the Do 17M did little to remedy these defects.

General re-equipment of the Do 17E-mounted Kampfgruppen was held in abeyance pending availability of the much improved second generation Do 17Z which was following the Do 17M by less than a year and utilised most of the gigs and tooling employed by the earlier model.

The Do 17P reconnaissance equivalent production was launched in 1938 by Henschel, Hamburger Flugzeubau and Siebel, a total of 330 being built for the Aufklärungsgruppen.

In July 1937, at about the time these first production models were reaching their first squadrons, an international military aircraft competition was staged at Dijbendorf, near Zilrich in Switzerland. One of the competitors was the French Dewoitine D 510, generally considered at that time to be the best single seat fighter in service anywhere in Europe. This fast and manoeuvrable little fighter was totally out-classed by an example of the Do 17, a twin engined bomber even though this was not revealed at the time. The Do 17 concerned was a specially stripped down prototype, the Do 17 V8, fitted with DB 600A engines specially boosted to give 1000 hp each.
The Do 17 V8’s performance had many side effects, not least on fighter design thinking in countries both inside and outside Europe. A more direct result was an expression of interest in the Do 17 itself from the Yugoslav government, which eventually placed an order for 20 of the German bombers. These export examples were designated Do 17K, and at the request of the customers were powered by Yugoslav built 980 hp French Gnome Rhone 14 N radial engines. The ‘pure’ bombers were designated Do 17Kb 1; reconnaissance models were designated Do 17Ka 2 and Ka 3, the latter doubling also in the bombing and attack roles. In addition to those supplied from German production, manufacture of the Do 17K was also undertaken under licence, in 1939 40, by the Drzavria Fabrika Aviona (state aircraft factory) at Kraljevo, near Belgrade. The additional available power gave the Do 17K a useful increase in both speed and range, notwithstanding an improved internal bombload (in the Kb 1) of 1000 kg (2205 lb) and an armament increased to three 0.312 in (7.92mm) FN Browning machine guns and one 20mm (0.79 in) Hispano cannon. Seventy Do 17Ks were still in service with the Yugoslav air force when the country was invaded by Germany in early April 1941. Later that month two of them escaped to Greece with a consignment of gold bullion. Losses during the fighting in Yugoslavia were fairly heavy, but those Do 17Ks that survived were passed on in early 1942, after the occupation, to the newly created Croatian air force.
The improvements in weapon capacity and performance exhibited by the Do 17K had, in fact, been evolved for two generally similar versions for the Luftwaffe, the Do 17M bomber and Do 17P reconnaissance bomber, the increased power being derived respectively from a pair of 900 hp supercharged Bramo 323AA or 865 hp BMW 132M radial engines. In 1938 these began gradually to replace the Do 17Es and Do 17Fs in service, and by September 1938 combined production of the Do 17E, F, M and P series totalled 580.
Three experimental models to be evolved during 1937 38 were the Do 17L, Do 17R and Do 17S. The Do 17L (two prototypes only) was a four seat pathfinder version with 900hp Bramo 323AA engines. The two Do 17R prototypes were testbeds, one powered by 950 hp Daimler Benz DB 600G engines and the other by 1100 hp DB 601As. The Do 17S (three built, first flight early 1938) was a high-speed reconnaissance version with DB 600G engines and a crew of four. None of these went into production, but between them the R and S series led to the Do 17U, of which 15 were produced in 1938 and distributed among nine Karripfgruppen (bomber groups) for pathfinder duties. The Do 17U carried a crew of five and was powered by 950 hp DB 600A engines.

The final version in the Do 17 production series, and the one produced in the greatest quantity, was the Do 17Z. The Do 17Z, the design of which begun early 1938, featured an entirely new forward fuselage, A progressive development of the Do 17S/Do 17U, it appeared in late 1938 and broke away from the Do 17’s earlier ‘Flying Pencil’ image by adopting as standard the deeper, more angular and more extensively glazed nose section first seen on the Do 17S.

This permitted a heavier defensive armament (which the Do 17 now needed) of up to six MG 15 guns, five of them aimed manually. The Do 17Z series carried a crew of four or five, and were powered at first by Bramo 323A 1 and (from the Z 2) by 1000 hp Bramo 323P series engines.

The downward-firing MG 15 machine gun which was poked through a hatch in the floor of proceeding Do 17 versions had too limited a field of fire to provide protection from below and to the rear. Crew accommodation had always been cramped thus, for the Do 17Z, the cockpit roof raised and fully glazed. The nose containing the bombardier’s station was extensively glazed with a series of small, flat panels, and the lower part was bulged and extended aft to a point just forward of the wing leading edge, terminating in a position for an aft-firing MG 15 machine gun.

Approximately 525 examples of the Do 17Z were built, of which the Do 17ZA (delivered from January 1939) and the Do 17Z 2 (the most numerous sub type) were bombers, the Do IV 3 (22 built) a recon-naissance model, the Do 17ZA a dual control training version of the Z 2, and the Do IV 5 a version of the Z 2 for rescue duties.

The pre-series Do 17Z-0, which appeared late in 2938, was a four-seat bomber, defensive armament comprising three 7,0mm MG 15 guns – one on a pillar-type mounting at the rear of the flight deck, a second protruding through the starboard panels of the windscreen and the third on a hemispherical mounting firing below the fuselage. This armament was augmented on the production Do 17Z-1 by a fourth MG 15 protruding through the nose cone. Appearing before the end of 1938, the Do 17Z-1 was under-powered by its two 900 hp BMW-Bramo 323A-1 radial engines when carrying a full 2205 lb / 1000 kg bombload. Bombload wasreduced to 1100 lb / 500 kg, but was restored to the full load early in 1939 with the appearance of the Do 17Z-2 with 1000 hp Bramo 323P engine with two-speed superchargers. Restoration of the full bombload dictated some reduction in fuel load reducing penetration with maximum load to 205 mi / 330 km.

Lacking the load carrying capability of the He 111 and the speed of the Ju 88, production was tapering off by the end of 1939 and terminated during early summer of 1940 after about 500 were delivered.

The Do 17Z-2 was to perform the first operational sortie of WW II when aircraft of III/KG 2 took-off from Heiligenbeil, East Prussia, 45 minutes after the official outbreak of war, to bomb approaches to the rail bridge at Dirschau, a major link across the Polish Corridor.

Equipping nine Kampfgruppen of KG 2, KG 3, KG 76 and KG 77, the Do 17Z-2 was in the forefront when the first attacks on channel convoys took place in July 1940, and the Kommodore of KG 2, Oberst Fink, was assigned the title of Kanalkampfführer with the task of clearing the channel of British shipping, his Do 17Z-2s providing the principle component of the battle group entrusted with this mission. On Adler Tag the Do 17Z-2s of KG 2 bombed Eastchurch as the sole Kampfgeschwader failing to receive Goering’s postponement order, losing four aircraft in the process.

The Do 17Z-2s of KG 3 bombed Eastchurch and Rochester two days later, and on the 16th those of KG 76 attavked West Malling, following up this mission with attacks on Biggin Hill and Kenley on the 18th.
The incursions over Britain of the Do 17Z rapidly revealed the deficiencies of its defensive armament, fotward maintenance units first adding two MG 15 machine guns which could be fired laterally from the radio operator’s position and then another pair to provide a total of eight defensive machine guns.

The Dornier bomber possessed good manoeuvrability and its structural integrity enabled it to undertake shallow diving attacks at speeds in excess of 270 mph / 590 kph, but it carried no armour protection for its crew. Attrition remained high and by mid-September the numerical importance of the Do 17 began to dwindle.

Luftwaffe strength returns showed a total of 493 Do 17s on charge on December 2, 1939. Of these, 352 were Do I7s (mostly Z¬2s), 12 were Do 17Rs, 41 were Do 17Ms, and 83 were Do 17Ps. The P and Z models were thus the principal versions encountered during the early attacks on Poland, France, the Low Countries and Britain in 1939 40. They performed reliably and effectively and, despite a fairly high rate of attrition, were popular with their crews. The Do 17 “Flying Pencil” was the first type of German aircraft shot down by an RAF single-seat fighter during the war (a Hurricane of No 1 Squadron on 30 October 1939). Dornier 17 production ended in July 1940 after approximately 1200 of all models had been built. Only one Geschwader (wing), KG2, used the 17Z for more than a year after the invasion of the Soviet Union.

When it became necessary to find improvized night fighters to counter RAF raids on German held targets, a small number of Do 17Zs were converted to this role. After trials in 1939 with a Do 17Z 6 K= I (screech owl) prototype, nine more Z 3s were converted in 1940 to three seat Do 17Z 10 Kauz II night fighters, with a battery of two 20 mm (0.79in) MF FF cannon and four 7.9 mm (0.312 in) MG 17 machine guns in a ‘solid’ nose. Operating with Nachtjagdgeschwader 1 in Holland, the Do 17ZA0 scored its first ‘kill’ on the night of October 18/19, 1940.

In 1938, in the hope of attracting further foreign orders for the bomber, Dornier took two of the pre production Do 17Z Os and used them as export demonstration aircraft under the new RLM type number Do 215. Redesignated Do 215 V1 (with Bramo 323 engines) and Do 215 V2 (with 980 hp Gnome-Rhone 14 N radials), the latter was demonstrated to Yugoslavia, but without securing any orders. The only order forthcoming was from Sweden, which was shown the Do 215 V3, another former Do 17Z 0 refitted with 1075 hp DB 601A inverted V engines. Eighteen of these were ordered for the Swedish air force in mid 1939 as Do 215A 1s, but were not completed before the war. Only three Do 215B 1s had been completed by the end of 1939, but production continued in parallel with the radial engined Do 17Z, and ninety two Do 215B-1s and B 4s were delivered to the Luftwaffe in 1940, production being completed in 1941 with a further six machines.

The first of the batch was flown in December 1939, and all were taken over by the Luftwaffe, with minor modifications, as Do 215B 0s or B 1s. Delivered in early 1940, they were followed into production by two generally similar Do 215B 3s for the Soviet Union (the B 2 was not built); and then by the principal Luftwaffe model, the Do 215B 4 (similar to the B 1, and also with 1100 hp DB 601Aa engines, but fitted with different cameras); and the Do 215B 5.
This final Do 215B version, some 20 of which were converted on the line from Do 215B 4s, was produced in the latter half of 1940 as a night fighter/intruder aircraft, and had a ‘solid’ nose similar to that of the Do 17Z 10 in which were installed four MG 17 machine guns and two 20 mm (0.79 in) MG FF cannon. The Do 215B 4 differed from the B-1 solely in the type of cameras installed, an RB 50/30 camera being mounted beneath the ventral gun position, and an RB 20/30 camera being mounted on the crew entry hatch. In addition to the cameras, twenty 110 1b (50 kg) bombs could be carried. Two slightly modified machines designated Do 215B 3 were exported to the Soviet Union during the winter of 1939 40.

Several Do 215B-1 airframes were converted to Do 215B 5 night fighter configuration and delivered to NJG.2 during late 1940 for operation from Gilze Rijen in the Netherlands, these undertaking intruder sorties against RAF bomber bases. In July 1941 Nachtjagdgeschwader 1 in Holland was the first operational Luftwaffe aircraft to carry the early Telefunken FuG 202 Lichtenstein BC airborne interception radar. Oberleutnant Ludwig Becker of NJG 1, later to become one of the Luftwaffe’s leading night fighter pilots, made the first ‘kill’ using this equipment on August 9, 1941. The Do 215B 5 was fitted with a solid nose housing one 20 mm MG FF cannon and four 7.9 mm. MG 17 machine guns.

In all, 101 Do 215Bs were built before production ended in January 1941. By this time mainstream development of the Do 17/215 bomber concept was well under way in the more advanced form of the Dornier Do 217, the first examples of which had entered service towards the end of the previous year. After 1942, virtually no Do 215s remained in service with first line units, those which survived being reallocated mostly to test and development work. The Do 17, however, following its replacement by the Do 217 in 1942, found a new career as a glider tug and continued in the role to the end of the war.

Gallery

Do-17
Engine: 2 x BMW Bramo 323P, 770kW
Max take-off weight: 8890 kg / 19599 lb
Empty weight: 5230 kg / 11530 lb
Wingspan: 18.0 m / 59 ft 1 in
Length: 15.8 m / 51 ft 10 in
Height: 4.6 m / 15 ft 1 in
Wing area: 55.0 sq.m / 592.01 sq ft
Max. Speed: 410 km/h / 255 mph
Cruise speed: 376 km/h / 234 mph
Ceiling: 9000 m / 29550 ft
Range w/max.fuel: 2000 km / 1243 miles
Armament: 4 x 7.9mm machine-guns, 1000kg of bombs
Crew: 4

Do.17E
Engines: 2 x BMW VI, 750 hp.

Do 17E-1
Span: 18 m (59 ft 1 in)
Length: 16.25 m (53 ft 3.75 in)
Gross weight: 7040 kg (15,520 lb)
Maximum speed: 355 km/h (220 mph)

Do 17Z
Engines: 2 x Bramo Fafnir, 1000 hp
Top speed: 255 mph
Cruise: 216 mph
Range: 750-1000 mi
Wingspan: 59 ft 0 in
Length: 53 ft 0 in

Do 17M-1
Span: 18 m (59 ft 1 in)
Length: 16.10 m (52 ft 9.75 in)
Gross weight 8000 kg (17,637 lb)
Maximum speed: 410 km/h (255 mph)

Do 17Z 2
Span: 18 m (59 ft 1 in)
Length: 15.79 m (51 ft 9.75 in)
Gross weight: 8590 kg (18,938 lb)
Maximum speed: 360 km/h (224 mph)
Armament: 2 x 7.92mm MG 15 mg

Do.215
Engines 2 x 1,075 hp Daimler Benz DB 601 A.
Length: 51.75 ft (15.75 m).
Wing span: 59.1 ft (18m).
Weight empty: 12,730 lb (5,770 kg).
Max bomb load: 2,200 lb (1,000 kg)
Max speed: 300 mph (480 kph).
Ceiling: 29,000 ft. (8,800m) fully loaded.
Range: 1,860 miles (3,000 km).
Range: 900 sm with 2200 lb bombs.
Crew: 4.
Armament: 4 x mg.

Do 215A-1
Engines: 2 x 1,075 hp Daimler Benz DB 601A.
Max speed: 289 mph (465 kph) with a 2,200 lb (1000 kg) bomb load.
Max cruise: 257 mph (413.5 kph).
Normal range: 965 mls (1553 km).
Service ceiling: 31,170 ft (9500 m).

Do 215B-1
Engines: 2 x 1,075 hp Daimler Benz DB 601Aa.
Max speed: 239 mph (385 kph) at sea level, 289 mph (465 kph) at 13,123 ft (4 000 m).
Tactical radius with max bomb load: 236 mls (380 km).
Max ferry range: 1,522 mls (22450 km).
Wing span: 59 ft 0in (18.00 m).
Length: 52 ft 0 in (15.80 m)
Height: 15 ft 1 in (4.60 m).
Wing area, 592 sq.ft (55.0 sq.m).
Crew: 4.
Armament: four 7.9 mm MG 15 mg.
MTOW: 19,400 lb (8 800 kg)

Do 215B-3

Do-215B-4
Engines: 2 V-12 Daimler-Benz DB 601Aa with 1100hp/820kW
Max speed: 239 mph (385 kph) at sea level, 289 mph (465 kph) at 13,123 ft (4 000 m).
Climbing Rate: 1000m in 2min, 18sec
Operational Altitude: 9000m
Weight empty: 5775kg
MTOW: 19,400 lb (8 800 kg)
Wing span: 59 ft 0in (18.00 m).
Length: 52 ft 0 in (15.80 m)
Height: 15 ft 1 in (4.60 m).
Wing area, 592 sq.ft (55.0 sq.m).
Tactical radius with max bomb load: 236 mls (380 km).
Max ferry range: 1,522 mls (22450 km).
Armament: One or two 7,92mm Machine Guns in the Nose, two
7,92mm MG in the front glass, two 7,92mm MG in each of the side windows, one 7,92mm MG on the back of the cockpit, one 7,92mm MG in the belly.
Max Bomb load: 1000kg
Crew: 4.

Do 215B-5
Engines: 2 x 1,075 hp Daimler Benz DB 601Aa.
Wing span: 59 ft 0in (18.00 m).
Length: 52 ft 0 in (15.80 m)
Height: 15 ft 1 in (4.60 m).
Wing area, 592 sq.ft (55.0 sq.m).
MTOW: 19,400 lb (8 800 kg).