The Dornier Do17 („Flying Pencil”) made its first flight in November 1934 and was intended as a fast mail-carrier for Deutsche Lufthansa. Rejected by that airline after three machines (all with single fins) had been completed, it was taken up as a high speed bomber by the Reichsluftfahrtministerium (RLM, Ministry of Aviation) the following year and made a spectacular public debut, now with a twin tail assembly, at Zurich in the 1937 International Military Aircraft Competitions. By this time, bomber squadrons of the Luftwaffe were already being equipped with the first two production models, the Do 17E and Do 17F, and in 1938 both of these versions were seeing service in the Spanish Civil War. Also in 1938 the next major series, the Bramo 323 powered Do 17M-l, entered production, closely followed by the reconnaissance Do I7 P with BMW 132N engines. After small numbers of the Do 17 S (reconnaissance version) and Do 17 U (pathfinder) had been built with DB 600A inline engines, a return to the radial Bramo 323 engineswas made in 1939 with the Do 17Z.
On the outbreak of war the Luftwaffe had in service the Do 17 M and Do 17 Z bombers, and the Do I7 P and a handful of Do 17Fs
Production: 2139 aircrafts.