[5] Many aspects of the aircraft echoed nautical arrangements of the time, including the flight deck, which bore a strong resemblance to the bridge of a vessel.

On the main deck was a smoking room with its own wet bar, a dining salon, and seating for the 66 passengers which could also be converted to sleeping berths for night flights.

[1] To satisfy skeptics, on its 70th test flight on 21 October there were 169 on board of which 150 were passengers (mostly production workers and their families, and a few journalists), ten were aircrew and nine were stowaways.

To introduce the airliner to the potential United States market[1] the Do X took off from Friedrichshafen, Germany, on 3 November 1930, under the command of Friedrich Christiansen for a transatlantic test flight to New York.

The journey was interrupted at Lisbon on 29 November, when a tarpaulin made contact with a hot exhaust pipe and started a fire that consumed most of the left wing.

[8] The flight continued north via San Juan to the United States, reaching New York on 27 August 1931,[8] almost ten months after departing Friedrichshafen.

[1] The Do X and crew spent the next nine months there as its engines were overhauled, and thousands of sightseers made the trip to Glenn Curtiss Airport (now LaGuardia) for sightseeing tours.

The Great Depression dashed Dornier's marketing plans for the Do X, and it departed from New York on 21 May 1932 via Newfoundland and the Azores to Müggelsee, Berlin, where it arrived on 24 May and was met by a cheering crowd of 200,000.

After plans for a first-class passenger service (Genoa–Gibraltar) were deemed unfeasible, the X2 and X3 were used for officer training cruises, aeronaval manoeuvres, and publicity flights.

Germany's original Do X was turned over to Deutsche Luft Hansa, the German national airline, after the financially strapped Dornier company could no longer operate it.

The voyage ended after nine days when the flying boat's tail section tore off during a botched, overly-steep landing on a reservoir lake near Passau.

While never a commercial success, the Dornier Do X was the largest heavier-than-air aircraft of its time, and demonstrated the potential for an international passenger air service.