Dornier Do 18 - Design and Development

Design and Development

In 1934, the Dornier Flugzeugwerke started development of a new twin engined flying boat to replace the Dornier Do J "Wal" (Whale) in both military and civil roles. The resultant design, Do 18 retained the layout of the Wal, with a metal hull fitted with distinctive stabilising sponsons, and powered by two engines above the wing in a push-pull layout, but was aerodynamically and hydrodynamically more efficient. It was planned to be powered by two of the new Junkers Jumo 205 diesel engines. Although heavy, these promised to give much lower fuel consumption than conventional petrol engines of similar power.

The first prototype, the Do 18a, registration D-AHIS (and named Monsun by Lufthansa) flew on 15 March 1935, powered by two of the earlier 410 kW (550 hp) Junkers Jumo 5c diesels as the planned Jumo 205s were not yet available. It was lost on 2 November 1935 over the Baltic during high-speed tests. Three further prototypes followed, two (the Do 18d and Do 18b) being prototype military aircraft, and the Do 18c (later redesignated Do 18 V3), a civil prototype.

The Do 18c was delivered to Lufthansa as a Do 18E civil transport (D-ABYM Aeolus), quickly followed by a further two aircraft, (D-AANE Zyklon and D-ARUN Zephir) with a final Do 18E (D-AROZ Pampero) being built in 1938.

A further civil Do 18 was the Do 18F, a modified aircraft with longer wingspan and higher weights built for extended-range flights. The sole Do 18F, D-ANHR, first flew on 11 June 1937. It was later modified with 656 kW (880 hp) BMW 132N radial engines to test a possible upgrade for the Luftwaffe's aircraft, flying in this form on 21 November 1939 as the Do 18L. It suffered cooling problems, however, and further development of the radial powered Do 18 was abandoned.