The Curtiss Model H was a family of classes of early long-range flying boats, the first two of which were developed directly on commission in the United States in response to the £10,000 prize challenge issued in 1913 by the London newspaper, the Daily Mail, for the first non-stop aerial crossing of the Atlantic. As the first aircraft having transatlantic range and cargo-carrying capacity, it became the grandfather development leading to early international commercial air travel, and by extension, to the modern world of commercial aviation. The last widely produced class, the Model H-12, was retrospectively designated Model 6 by Curtiss' company in the 1930s, and various classes have variants with suffixed letters indicating differences.
Design and development
Having transatlantic range and cargo carrying capacity by design, the first H-2 class (soon dubbed "The Americans" by the Royal Navy) was quickly drafted into wartime use as a patrol and rescue aircraft by the RNAS, the air arm of the British Royal Navy. The original two "contest" aircraft were in fact temporarily seized by the Royal Navy, which later paid for them and placed an initial follow-on order for an additional 12 – all 14 of which were militarized (e.g. by adding gun mounts) and designated the "H-4" (the two originals were thereafter the "H-2" Models to air historians). These changes were produced under contract from Curtiss' factory in the last order of 50 "H-4s", giving a class total of 64, before the evolution of a succession of larger, more adaptable, and more robust H-class models. This article covers the whole line of nearly 500 Curtiss Model H seaplane flying boat aircraft known to have been produced, since successive models – by whatever sub-model designation – were physically similar, handled similarly, essentially just being increased in size and fitted with larger and improved engines – the advances in internal combustion engine technology in the 1910s being as rapid and explosive as any technological advance has ever been.
When London's Daily Mail newspaper put up a £10,000 prize for the first non-stop aerial crossing of the Atlantic in 1913, American businessman Rodman Wanamaker became determined that the prize should go to an American aircraft and commissioned the Curtiss Aeroplane and Motor Company to design and build an aircraft capable of making the flight. The Mails offer of a large monetary prize for "an aircraft with transoceanic range" (in an era with virtually no airports) galvanized air enthusiasts worldwide, and in America, prompted a collaboration between the American and British air pioneers: Glenn Curtiss and John Cyril Porte, spurred financially by the nationalistically motivated financing of air enthusiast Rodman Wanamaker. The class, while commissioned by Wanamaker, was designed under Porte's supervision following his study and rearrangement of the flight plan and built in the Curtiss workshops. The outcome was a scaled-up version of Curtiss' work for the United States Navy and his Curtiss Model F. With Porte also as Chief Test Pilot, development and testing of two prototypes proceeded rapidly, despite the inevitable surprises and teething troubles inherent in new engines, hull and fuselage.
The Wanamaker Flier was a conventional biplane design with two-bay, unstaggered wings of unequal span with two tractor engines mounted side by side above the fuselage in the interplane gap. Wingtip pontoons were attached directly below the lower wings near their tips. The aircraft resembled Curtiss' earlier flying boat designs, but was considerably larger in order to carry enough fuel to cover 1,100 mi (1,770 km). The three crew members were accommodated in a fully enclosed cabin.
Named America and launched 22 June 1914, trials began the following day and soon revealed a serious shortcoming in the design: the tendency for the nose of the aircraft to try to submerge as engine power increased while taxiing on water. This phenomenon had not been encountered before, since Curtiss' earlier designs had not used such powerful engines. In order to counteract this effect, Curtiss fitted fins to the sides of the bow to add hydrodynamic lift, but soon replaced these with sponsons to add more buoyancy. Both prototypes, once fitted with sponsons, were then called Model H-2s incrementally updated alternating in succession. These sponsons would remain a prominent feature of flying boat hull design in the decades to follow. With the problem resolved, preparations for the transatlantic crossing resumed, and 5 August 1914 was selected to take advantage of the full moon.