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Dornier Do-17 / Do-215
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.
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 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.
 Dornier Do.17Z
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.
 Do 17Z
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.
 Do 17Z bombardier station
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 reconnaissance 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.
 D0 17Z-2
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.
 Dornier Do17/Z testbed for Lorin ramjet
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.
Do 17Z
 Do.215B-1
 Do.215
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.
 Hauptmann Becker in his Do 17Z-6
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.
Do-17
Dornier Do 17
Dornier Do 215
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