Dornier Do J The Dornier Do J " Wal " ( " whale " ) was a twin - engine German flying boat of the 1920s designed by " Dornier Flugzeugwerke " . The Do J was designated the Do 16 by the Reich Air Ministry ( " RLM " ) under its aircraft designation system of 1933 . Design and development . The Do J was a fairly modern ( compared to those models of World War I ) , design with a high - mounted strut - braced monoplane wing . Two piston engines were mounted in tandem in a nacelle above the wing and in line with the hull ; one engine drove a tractor and the other drove a pusher propeller . The Do J made its maiden flight on 6 November 1922 . The flight , as well as most production until 1932 , took place in Italy because of the restrictions on aviation in Germany after World War I under the terms of the Treaty of Versailles . Dornier began to produce the " Wal " in Germany in 1931 , production went on until 1936 . In the military version ( " Militärwal " in German ) , a crew of two to four rode in an open cockpit near the nose of the hull . There were one MG - position in the bow in front of the cockpit and one to two amidships . Beginning with Spain , military versions were delivered to Argentina , Chile and the Netherlands for use in their colonies ; examples were also sent to Yugoslavia , the Soviet Union and to the end of production Italy and Germany . The main military users , Spain and the Netherlands , manufactured their own versions under licence . Several countries , notably Italy , Norway , Portugal , Uruguay , Great Britain and Germany , employed the " Wal " for military tasks . The civil version ( " Kabinenwal " or " Verkehrswal " ) had a cabin in the nose , offering space for up to 12 passengers , while the open cockpit was moved further aft . Main users of this version were Germany , Italy , Brazil and Colombia . The Do J was first powered by two 265 kW ( 355 hp ) Rolls - Royce Eagle IX engines . Later versions used nearly every available engine on the market from makers like Hispano - Suiza , Napier & Son , Lorraine - Dietrich , BMW , and even the US - built Liberty Engine . The " 10 to - Wal " used by " Deutsche Lufthansa " for their mail service across the South Atlantic from 1934 to 1938 had a range of , and a ceiling of 3 , 500 m ( 11 , 480 ft ) . Over 250 " Wals " were built by CMASA and Piaggio in Italy , CASA in Spain , Kawasaki in Japan , Aviolanda in the Netherlands and Dornier in Germany . Numerous airlines operated " Wals " on scheduled passenger and mail services with great success . The source Robert L . Gandt , in 1991 , ( pages 47 – 48 ) lists the following carriers : SANA and Aero Espresso of Italy ; Aero Lloyd and Deutsche Luft Hansa of Germany ; SCADTA of Columbia ; Syndicato Condor of Brazil ; Nihon Koku Yuso Kaisha of Japan . According to " Nicolaou , 1996 " the Dornier " Wal " was " easily the greatest commercial success in the history of marine aviation " . The Colombian Air Force used " Wals " in the Colombia - Peru War in 1932 - 1933 . Pioneering flights . The Norwegian polar explorer Roald Amundsen accompanied by Lincoln Ellsworth , pilot Hjalmar Riiser - Larsen , and three other team members used two Dornier seaplane s in his unsuccessful attempt to reach the North Pole in 1925 . His two aircraft , " N - 24 " and " N - 25 " , landed at 87° 44 ' north . It was the northernmost latitude reached by any aircraft up to that time . The planes landed a few miles apart without radio contact , yet the crews managed to reunite . One of the aircraft , the N - 24 , was damaged . Amundsen and his crew worked for over three weeks to prepare an airstrip to take off from the ice . They shoveled 600 tons of ice while consuming only one pound ( 454 g ) of daily food rations . In the end , six crew members were packed into the N - 25 . Riiser - Larsen took off , and they barely became airborne over the cracking ice . They returned triumphant when everyone thought they had been lost . On 18 August 1930 , Wolfgang von Gronau started on a transatlantic flight in the same Dornier " Wal " ( D - 1422 ) Amundsen had flown , establishing the northern air route over the Atlantic , flying from Sylt ( Germany ) - Iceland - Greenland - Labrador - New York ) in 47 flight hours . In 1932 von Gronau flew a Dornier " Wal " ( D - 2053 ) called the " Grönland Wal " ( Greenland Whale ) on a round - the - world flight . In 1926 Ramón Franco became a national Spanish hero when he piloted the " Plus Ultra " on a trans - Atlantic flight . His co - pilot was Julio Ruiz de Alda Miqueleiz ; the other crew members were Teniente de Navio ( Navy Lieutenant ) Juan Manuel Duran and the mechanic Pablo Rada . The ' Plus Ultra ' departed from Palos de la Frontera , in Huelva , Spain on 22 January and arrived in Buenos Aires , Argentina on 26 January . It stopped over at Gran Canaria , Cape Verde , Pernambuco , Rio de Janeiro and Montevideo . The 10 , 270 km journey was completed in 59 hours and 39 minutes . The event appeared in most major newspapers world wide , although some of them underlined the fact that the airplane itself , plus the technical expertise were foreign . Throughout the Spanish - speaking world , the Spanish aviators were wildly acclaimed , particularly in Argentina and Spain where thousands gathered at Plaza de Colón in Madrid . ( Wikimedia Commons has media related to " Plus Ultra " - see below . ) In 1929 Franco attempted another trans - Atlantic flight , this time crashing the airplane in the sea near the Azores . The crew was rescued days later by the aircraft carrier HMS " Eagle " of the British Royal Navy . The Portuguese military aviator Sarmento de Beires and his crew made the first night aerial crossing of the South Atlantic in a Dornier J named " Argos " . The crossing was made on the night of 17 March 1927 from Portuguese Guinea to Brazil . Two Dornier " Wals " ( D - ALOX " Passat " and D - AKER " Boreas " ) also played an important role in the Third German Antarctic Expedition of 1939 . South Atlantic air mail . The biggest and last versions of the " Wal " , the eight and ten tonne variants ( both versions also known as " Katapultwal " ) , were operated by " Lufthansa " on their South Atlantic airmail service from Stuttgart , Germany to Natal , Brazil . On route proving flights in 1933 , and a scheduled service beginning in February 1934 , " Wals " flew the " trans - ocean " stage of the route , between Bathurst , the Gambia in West Africa and Fernando de Noronha , an island group off South America . At first , there was a refueling stop in mid - ocean . The flying boat would land on the open sea , near a converted merchant ship . This vessel was equipped with a " towed sail " on to which the aircraft taxied . From there it was winched aboard by a crane , refueled , and then launched by catapult back into the air . However , landing on the big ocean swells tended to damage the hull of the flying boats , especially the smaller " 8 - tonne Wal " . From September 1934 a second merchantman was available , so that " Lufthansa " now had a support ship at each end of the trans - ocean stage , providing radio navigation signals and catapult launchings . When they did not have to take off from the water under their own power , the flying boats could carry more fuel . Once the incoming mail from Europe had arrived in West Africa ( also by " Wal " from the Canary Islands ) , the support ship would chug out to sea in the direction of South America for 36 hours , before launching the airplane with its catapult . On the return trip a " Wal " would fly the stage from Natal to Fernando de Noronha , and then be carried out to sea overnight . The same airplane was then catapulted off to fly to West Africa the following morning , i . e . after twelve hours travel on the ship . From April 1935 the ships no longer carried the flying boats out to sea . The " Wal " was launched off shore , and flew the entire distance across the ocean . This cut the time it took for mail to get from Germany to Brazil from four days down to three . The first ship converted to a mid - Atlantic refueling stop was the " SS Westfalen " , a freight and passenger liner which became out - dated for carrying mail and passengers shortly after World War I due to its small size and low cruising speed . The second vessel was the MS " Schwabenland " . In 1936 a new support ship went into service , the MS " Ostmark " , which Lufthansa had purpose - built as a seaplane tender . " Wals " made over 300 crossings of the South Atlantic in regular mail service ( Gandt , 1991 , pages 47 – 48 ) . The " 8 - tonne Wal " was not a success , only two being built . The six " 10 - tonne Wals " flew the South Atlantic from 1934 until late 1938 , although aircraft of more recent design began replacing them from 1937 . From 1925 the French airline " Compagnie Générale Aéropostale " operated an airmail service on much the same route , from France to Brazil . The mail was flown only as far as Dakar in Senegal , West Africa , and then shipped across the South Atlantic to Natal aboard converted destroyer s . The ocean crossing alone took five days , the whole trip eight days . From 1930 " Aéropostale " began trying to make the ocean crossing by air , but kept on losing planes and crews . " Air France " , which " Aéropostale " had become a part of , only began operating an " all air " service between Europe and South America in January 1936 , nearly two years after " Lufthansa " . That the Germans had succeeded in establishing the world ' s first regular intercontinental airline service where " Aéropostale " had failed , was due in no small part to the sturdy and seaworthy " Wal " and its reliable BMW engines . Variants . " Data from :