In a flying boat, the main source of buoyancy is the fuselage, which acts like a ship's hull in the water. Most flying boats have small floats mounted on their wings to keep them stable. All large seaplanes have been flying boats, their great weight supported on their hull.
The Curtiss Models F made up a family of early flying boats developed in the United States in the years leading up to World War I. Widely produced, Model Fs saw service with the United States Navy under the designations C-2 through C-5, later reclassified to AB-2 through AB-5. Several examples were exported to Russia, and the type was built under licence in Italy.
In configuration, these were biplane flying boats powered by a single engine mounted amongst the interplane struts and driving a pusher propeller. The pilot and a single passenger sat side-by-side in an open cockpit. The wing cellule was derived from the Model E landplane and was of two-bay, unstaggered, equal-span construction with large ailerons mounted on the interplane struts and extending past the span of the wings themselves. The earliest examples of this design were built and sold by Curtiss in 1912 without any designation applied to them; the Model F name only coming into use the following year. Confusingly, Curtiss also used the designation Model E to refer to some early machines in this family, although these were quite distinct from Curtiss landplanes that bore this same designation and all but identical to the Model Fs.
Model Fs built from 1918 featured a revised, unequal-span wing that incorporated the ailerons into the upper wing and sponsons on the sides of the hull to improve the aircraft's handling in water. These were known as the Model MF (for Modernised-F), and years later as the Seagull in the post-war civil market.
The US Navy initially purchased four of these aircraft in addition to the Freak Boat (C-1/AB-1) that it had already obtained and which was retrofitted to approximately the same design as the others. One of these, the C-2 became the first aircraft to fly under automatic control on 30 August 1913 when fitted with a gyroscopic stabiliser designed by Elmer Sperry. The same aircraft (by now redesignated AB-2) then became the first aircraft to be launched by catapult from a warship while underway when it took off from USS North Carolina on 5 November 1915. Her sister, AB-3, became the first US heavier-than-air aircraft to see military action when launched from USS Birmingham on 25 April 1914 on a scouting mission over Veracruz during the United States Occupation of Veracruz.
The US Navy bought another eight aircraft before the end of 1916, but orders in quantity only came following the type's selection as the Navy's standard flying-boat trainer in April 1917. An initial batch of 144 of the basic F model were ordered, followed by 22 MFs in 1918. Another 80 MFs were produced under license by the Naval Aircraft Factory. A small number of Model Es and Fs were also purchased by the US Army.
The Russian Navy purchased two batches of Model Fs in 1913-14 and operated them as part of the Black Sea and Baltic Sea fleets until replaced by the Model K shortly thereafter. In Italy, the Curtiss representative Enea Bossi secured rights for local licence-production of the Type F by the Zari brothers, who built eight examples at their workshop in Bovisia, near Milan. The first of these was demonstrated to the Italian Navy on Lake Como on 22 September 1914.
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 trans-Atlantic 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.
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 in 1913 put up a $10,000 prize for the first non-stop aerial crossing of the Atlantic, 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 two aircraft capable of making the flight. The Mail's offer of a large monetary prize for "an aircraft with transoceanic range" (in an era with virtually no airports) galvanized air enthusiasts world wide, and, in America, prompted a collaboration between the American and British air pioneers: Glenn Curtiss and Lt-Cdr Porte, spurred financially by the nationalistically motivated financing of air enthusiast Rodman Wanamaker. The class, while commissioned by Wanamaker, was actually a scaled-up version of Curtiss' work for the United States Navy and his Curtiss Model E. With Royal Navy Lt-Cdr Cyril Porte as Chief Test Pilot, development and testing of the two prototypes proceeded rapidly, despite the inevitable surprises and teething troubles inherent in new engines, hull and fuselage. Both prototypes, once fitted with sponsons, were then called Model H-2s and were incrementally updated alternating in succession, and were successfully fully tested by the late summer of 1914, when they were shipped to England. At this time they were scheduled for a transatlantic flight in August 1914, attempting to cross the North Atlantic Ocean by air — a trial canceled because of the outbreak of World War I.
The resulting Model H 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 Model H 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.
Christened America, trials of the first Model H began in June 1914 and 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. These sponsons would remain a prominent feature of flying boat hull design in the decades to follow. With the problem resolved, preparations for the crossing resumed, and 5 August 1914 was selected as the date.
These plans were interrupted by the outbreak of war, which also saw Porte, who had been selected to pilot the America, recalled to service with the British Royal Navy. Impressed by the capabilities he had witnessed, Porte urged the Admiralty to commandeer (and later, purchase) the America and her sister from Curtiss. This was followed by a decision to order a further 12 similar aircraft, one Model H-2 and the remaining as Model H-4s, four examples of the latter actually being assembled in the UK by Saunders. All of these were essentially identical to the design of the America, and indeed, were all referred to as "Americas" in Royal Navy service. This initial batch was followed by an order for another 50.
These aircraft were soon of great interest to the British Admiralty as anti-submarine patrol craft and for air-sea rescue roles. The initial Royal Navy purchase of just two aircraft eventually spawned a fleet of aircraft which saw extensive military service during World War I in these roles, being extensively developed in the process (together with many spinoff or offspring variants) under the compressed research and development cycles available in wartime. Consequently, as the war progressed, the Model H was developed into progressively larger variants, and it served as the basis for parallel developments in the United Kingdom under Cyril Porte which led to the "Felixstowe" series of flying boats with their better hydrodynamic hull forms, beginning with the Felixstowe F.2 — a hull form which thereafter became the standard in seaplanes of all kinds, just as sponsons did for flying boats.
Curtiss next developed an enlarged version of the same design, designated the Model H-8, with accommodation for four crew members. A prototype was constructed and offered to the United States Navy, but was ultimately also purchased by the British Admiralty. This aircraft would serve as the pattern for the Model H-12, used extensively by both the Royal Navy and the United States Navy. Upon their adoption into service by the RNAS, they became known as Large Americas, with the H-4s receiving the retronym Small America.
As built, the Model H-12s had 160 hp (118 kW) Curtiss V-X-X engines, but with these engines they were underpowered, so in Royal Naval Air Service (RNAS) service they were re-engined with the 275 hp (205 kW) Rolls-Royce Eagle I and then the 375 hp (280 kW) Eagle VIII. Porte redesigned the H-12 with an improved hull; this design, the Felixstowe F.2, was produced and entered service. Some of the H-12s were later rebuilt with a hull similar to the F.2, these rebuilds being known as the Converted Large America. Later aircraft for the U.S. Navy received the Liberty engine (designated Curtiss H-12L).
Curiously, the Curtiss company designation Model H-14 was applied to a completely unrelated design (see Curtiss HS), but the Model H-16, introduced in 1917, represented the final step in the evolution of the Model H design. With longer-span wings, and a reinforced hull similar to the Felixstowe flying boats, the H-16s were powered by Liberty engines in U.S. Navy service and by Eagle IVs for the Royal Navy. These aircraft remained in service through the end of World War I and remained in U.S. Navy service for some years after the war, most receiving engine upgrades to more powerful Liberty variants.
With the RNAS, H-12s and H-16s operated from flying boat stations on the coast in long-range anti-submarine and anti-Zeppelin patrols over the North Sea. A total of 71 H-12s and 75 H-16s were received by the RNAS, commencing patrols in April 1917, with 18 H-12s and 30 H-16s remaining in service in October 1918.
U.S. Navy H-12s were kept at home and did not see foreign service, but ran anti-submarine patrols from their own naval stations. Twenty aircraft were delivered to the U.S. Navy. Some of the H-16s, however, arrived at bases in the UK in time to see limited service just before the cessation of hostilities.
The Curtiss NC (Navy Curtiss, nicknamed "Nancy boat" or "Nancy") was a flying boat built by Curtiss Aeroplane and Motor Company and used by the United States Navy from 1918 through the early 1920s. Ten of these aircraft were built, the most famous of which is the NC-4, the first airplane to make a transatlantic flight. The NC-4 is preserved in the National Museum of Naval Aviation, at NAS Pensacola, Florida.
Manufacture of the "NCs" began in 1918 during World War I. The U.S. Navy wished for an aircraft capable of long ocean flights, both for Anti-submarine warfare patrol, and if possible with capability to fly across the Atlantic Ocean under their own power to avoid having to be shipped through ocean waters menaced by German submarines. This was very ambitious given the state of aviation at the time.
The Navy and Curtiss came up with one of the largest biplane designs yet produced, equipped with sleeping quarters and a wireless transmitter/receiver. It was originally powered by three V12 Liberty engines, of 400 hp (298 kW) each; during the testing phase a fourth engine was added, arranged as three tractors and one pusher. Maximum speed was 90 mph (144 km/h) the estimated maximum range was 1,500 mi (2,400 km).
On 4 October 1918, the first of these planes, the NC-1, made its first test flight with the early three-engine configuration. On 25 November, it flew again, with a world record 51 people on board. Armistice Day, signaling the end of the war in Europe, came before testing of the first NC and construction of the other three of the Navy's initial order had been completed.
The other three NCs, NC-1, NC-3, and NC-4, set out on what was intended as the first demonstration of transatlantic flight, via Newfoundland and the Azores, on 8 May 1919, with Marc Mitscher in the NC-1 in command. The group encountered severe weather off the Azores, and only the NC-4 made it through. The crew of NC-1 was rescued at sea and attempts to tow the aircraft to the Azores failed; NC-3 was forced to land some 205 mi (330 km) distance from the Azores, but the crew, led by Commander John Henry Towers, managed to sail her to Ponta Delgada unaided.
The Navy had two more sets of NCs constructed, numbered NC-5 through NC-8, and NC-9 and NC-10, through 1921.