Dornier Do X

Template:Infobox Aircraft The Dornier Do X was the largest, heaviest and most powerful flying boat in the world when it was produced by the Dornier company of Germany in 1929. The aircraft was conceived by Dr. Claudius Dornier and took seven years to design and another two years to build. In the design process, a one-to-one wooden mock-up, the first in aviation history, was built.

It was financed by the German Transport Ministry and was manufactured in a specially designed plant at Altenrhein, on the Swiss portion of Lake Constance, in order to circumvent the Treaty of Versailles, which forbade aircraft to be built in Germany after World War I.

While popular with the public, a lack of commercial interest and a number of (non-fatal) accidents prevented more than three models from being built.

Design

The Do X had an all-duralumin hull, with wings comprised of a steel-reinforced duralumin framework covered in heavy linen fabric, covered with aluminum paint.

It was initially powered by twelve 525 horsepower Siemens Jupiter radial engines (6 tractor propellers and 6 pushers), mounted in six tower nacelles on the wing. The air-cooled Jupiter engines were prone to overheating, and only able to lift the plane to an altitude of 425 m (1,400 feet), preventing it from making trans-Atlantic crossings. After completing 103 flights in 1930, the Do X was refitted with 610 horsepower Curtiss Conqueror water-cooled 12-cylinder inline engines. Only then was it able to reach the altitude of 500 m (1,650 feet) necessary to cross the Atlantic.

The plane was designed to carry 66 passengers long distance or 100 on shorter flights. The luxurious accommodation approached the standards of transatlantic liners. On the main deck was a smoking room with its own wet bar, a dining salon, and seating for the 66 passengers, which could be converted to sleeping berths for night flights. Aft of the passenger spaces was an all-electric galley, lavatories, and cargo hold. The cockpit, navigational office, engine control and radio rooms were on the upper deck. The lower deck held fuel tanks and nine watertight compartments, only seven of which were needed to provide full flotation.

Operation

The Flugschiff (flying ship), as it was called, was launched for its first test flight on 12 July, 1929. On 21 October, the plane made a test flight carrying 169 people; 150 passengers (mostly production workers and their families, and a few journalists), 10 crew and 9 'stowaways', who had not received tickets for the already very popular plane. The flight broke the world record for the number of people aboard an airplane, not to be beaten for another fifteen years. The plane taxied for 50 seconds before slowly ascending to an altitude of only 200 m (650 feet). As a result of the ship's size, passengers were asked to crowd together on one side or the other to help the aircraft make turns. It flew for 40 minutes at a maximum speed of 170 km/h (105 mph) and finally landed back on Lake Constance.

The Do X took off from Friedrichshafen, Germany on 3 November 1930, piloted by Friedrich Christiansen, commencing a transatlantic test flight. The route took the Do X to the Netherlands, England, France, Spain, and Portugal. The journey was interrupted at Lisbon on 29 November 1930, when a tarpaulin made contact with a hot exhaust pipe and started a fire that consumed most of the portside wing. After sitting in Lisbon harbor for six weeks while new parts were fabricated and the damage repaired, the flying boat continued (with several further mishaps and delays) along the Western African coast, across the Atlantic to South America (where the crew were greeted as heroes by the local German émigré communities).

The aircraft then went north to the United States, finally reaching New York on 27 August 1931. Here the plane and crew spent the next nine months as the Do X's engines were overhauled, and thousands of sightseers made the trip to Glenn Curtiss Airport (now LaGuardia Airport) to tour the leviathan of the air. The return trip began on 21 May 1932 from New York to Newfoundland, on to the Azores, and finally to Berlin on 24 May, where the Do X was met by a cheering crowd of 200,000.

Final fate

Germany's original Do X was turned over to Lufthansa, the national airline, after the financially strapped Dornier Company could no longer operate it. After a successful 1932 tour of German coastal cities, Lufthansa planned a Do X flight to Vienna, Budapest, and Istanbul for 1933. The voyage ended after nine days when the plane's tail section tore off during a botched, over-steep landing on a reservoir lake near the city of Passau. While the fiasco was successfully covered up and the plane repaired, it was then flown to Berlin, where it became the centerpiece of Germany's new aviation museum in 1934.

It remained an exhibit until it was destroyed in a RAF air raid during World War II in late November 1943. While never a commercial success, the Dornier Do X was the largest aeroplane of its time, a pioneer in demonstrating the potential of an international passenger air service and one of the most impressive aircraft built. A successor, the Do-XX, was envisioned by Dornier but never advanced beyond the design study stage.

Further models

Three Do Xs were constructed in total: the original operated by Dornier, and two other machines based on orders from Italy - the X2 (named Umberto Maddalena) and X3 (named Alessandro Guidoni). The Italian variants were essentially identical to the original with the exception of the powerplant and engine mounts. Each craft was powered by Fiat A-22R V12 water-cooled engines, with the six motor mounts being covered by a streamlined fairing. The Do X2 entered service in August, 1931, and the X3 followed in May, 1932. Both ships were based at the seaplane station at La Spezia, on the Ligurian Sea.

Italy's Do X3 Alessandro Guidoni, one of the three Do X's built.

Both orders originated with SANA, then the Italian state airline, but the aircraft were requisitioned and used by the Italian Air Force primarily for prestige flights and public spectacles. After plans for a first-class passenger service (Genoa-Gibraltar) were deemed unfeasible, the X2 and X3 may have been used for training and transport flights (one rumor has it that a Do X even ferried troops to Ethiopia in February, 1935). No evidence exists of their fate; presumably they were quietly broken up for scrap around 1935.

Operators

• Germany : Lufthansa
• Italy : Regia Aeronautica; SANA (state airline)

Specifications (Do XIa)

General characteristics

• Crew: 10-14
• Capacity: 66-100 passengers

Performance

Appearances in fiction

• Author Michael Moorcock featured the aircraft in his alternate universe fiction as a symbol of power and style emblematic of the lost era of the 1930's.
• The 1934 movie, The Perils of Pauline, features historic footage of the flight of the Do X.
• The 1985 Alphaville pop group music video "Jet Set" shows footage of the Dornier Do X.
• A Do X used as a mobile weapons lab appears in Albatross: Wings of Death, an episode of Lupin III. The plane depicted has a twin tail and only five engines.

External links

• Dornier Do X: Legendary Flying Boat

See also

• Short Sarafand - largest biplane flying boat

Aircraft of comparable role, configuration, and era

• Blohm & Voss BV 238
• Latécoère 521
• Hughes H-4 Hercules
• Bristol Brabazon
• Boeing Pelican