07/12/1929: First Flight of the Dornier Do X

DALLAS — Today, in 1929, the German flying boat Dornier Do X, a semi-cantilever monoplane powered by twelve engines mounted in six tower nacelles on the wing, performed its maiden flight with a crew of 14.

On October 21 of that same year, the Flugschiff, or "flying ship," carried 169 people: 150 passengers (mainly factory workers and their families, plus a few journalists), ten aircrew, and nine stowaways.

For 20 years, the flight would stand as the record for most people carried on a single aircraft in history.

Development

In 1929, the German manufacturer Dornier developed the largest, heaviest, and most powerful flying boat ever made: the Dornier Do X. Claude Dornier had the initial idea for the project in 1924. Planning began in late 1925, and it took more than 240,000 work hours to complete by June 1929.

The only landplane that was physically larger between the two World Wars was the Soviet Tupolev ANT-20 Maksim Gorki, which came out a few years later. However, with 53 tonnes maximum takeoff weight, it was not as hefty as the Do X, weighing 56 tons.

The German Transport Ministry provided funding for the Do X. To get around the terms of the Treaty of Versailles, which prohibited Germany from building any aircraft over certain speed and range restrictions following World War I, a specially created plant was constructed at Altenrhein, on the Swiss side of Lake Constance.

Do X Design

The Do X's hull was entirely made of duralumin, while its wings were made of a steel-reinforced structure wrapped in thick linen fabric and painted with aluminum.

12 Siemens-built Bristol Jupiter radial engines, rated at 391 kW (524 hp), were first installed in tandem push-pull arrangement, with six tractor propellers and six pushers positioned atop six strut-mounted nacelles above the wing.

To stabilize the mountings, an auxiliary wing was added to the nacelles. Sick of overheating, the air-cooled Jupiter engines could hardly get the Do X up to 425 m (1,394 ft).

Fuel tanks and nine watertight compartments—only seven of which were required for complete flotation—were located on the lower deck.

Passenger Experience

With the aircraft boasting three decks, the opulent guest accommodations were on par with those of transatlantic cruise ships.

The main deck included a dining salon, a smoking area with a wet bar, and seating for all 66 passengers, some of which could be turned into sleeping beds for night flights.

The cargo hold, restrooms, and all-electric galley were located aft of the passenger sections. On the upper deck were the radio rooms, engine control, navigational office, and cockpit.

The public liked this design, but more than three Do X could not be produced due to a lack of business interest and several non-fatal incidents.

A Notable Operation

On November 3, 1930, the Do X, piloted by Friedrich Christiansen, set out from Friedrichshafen, Germany, for a transatlantic test trip to New York, with the goal of introducing the airliner to the prospective U.S. market.

The Do X traveled through the Netherlands, the UK, France, Spain, and Portugal on its way to the U.S.

Following delays in Lisbon, the flying boat experienced a number of more disasters and delays as it traveled along Africa's western coast. By June 5, 1931, it had arrived in the Cape Verde islands, from where it crossed the Atlantic to reach Natal in Brazil.

Following its departure from Friedrichshafen, the flight continued northward via San Juan to the United States, arriving in New York on August 27, 1931, nearly 10 months later.

While its engines were being refurbished, the Do X and its crew spent the next nine months there, and thousands of tourists traveled to Glenn Curtiss Airport (now LaGuardia Airport [LGA]) for sightseeing excursions.

Final Years

The bankrupt Dornier corporation was unable to continue operating Germany's original Do X, therefore it was given to flag carrier Deutsche Luft Hansa.

Luft Hansa scheduled a Do X flight to Vienna, Budapest, and Istanbul for 1933 following a fruitful tour of German coastal cities in 1932.

Nine days into the journey, the flying boat's tail portion broke off following a poorly executed, extremely steep landing on a reservoir lake close to Passau.

Only with the Boeing 747 and the Airbus A380 would we see again aircraft with the top and middle deck used to accommodate passengers, and the bottom cargo deck used to carry luggage and any other form of cargo.

Article source: Dornier Museum