Dornier Do-X was the largest and heaviest flying boat, having 157 feet of wingspan and a maximum takeoff weight of more than 16 tons. It was built in 1929 by the German Transport Ministry in Switzerland, on the shores of Lake Constance, in order to comply with terms of the Treaty of Versailles, which forbade Germany from building certain classes of aircraft.
12 engines were installed and mounted in tandem “push-pull” configuration atop the wing, which could just barely haul the hulking craft up to an altitude of 1,650 feet. Do-X engines were not directly controlled by the pilot. The captain in the cockpit had to send orders for throttle adjustments to a flight engineer in the engine room.
Do-X was the luxurious boat of that time, with a dining salon, smoking longue, wet bar and comfortable seating for 70 to 100 passengers. The Do-X made its first test flight on July 12, 1929. A few months later, it carried a world-record 169 passengers on a 40-minute flight.
