The Curtiss H-1 'America' was a long range biplane seaplane, originally designed to fly across the Atlantic, and that became the basis of the wartime H-4, H-12 and H-16 in the US and the British Felixstowe F boats.
Two H-1s were ordered by Rodman Wanamaker, a department store owner with stores in New York and Philadelphia who wanted to win the Daily Mail’s £10,000 for the first trans-Atlantic flight, in August 1913. It was Wanamaker who gave it the name ‘America’.
The H-1 had much in common with earlier Curtiss flying boats, with two Curtiss OX inline engines powering pusher propellers carried between the wings. However in order to make the long flight more comfortable, it was given an enclosed cabin with space for two pilots and one mechanic. There was no attempt to streamline the canopy, which had simple vertical windows and a flat roof.
The H-1’s flying surfaces were designed by B. Douglas Thomas, a British designer who had worked for Sopwith before being hired by Curtiss to help develop successful tractor aircraft. He produced uneven span wings, with floats close to the tips of the shorter lower wings and ailerons on the upper wings. The ailerons had a tapering trailing edge, so the wings were widest at their tips. Thomas’s wings were a great success, and these or very similar wings were used across the Curtiss H and Felixstowe F boats. The tail had a large triangular fin with a curved rudder. The horizontal tail surfaces had a curved front and were mounted high on the tail. They also had a fixed forward section and moving control surfaces at the rear.
A second British contribution came from Lt John Porte of the Royal Navy who helped influence the design of the hull and acted as pilot. Porte would later go on to design the Felixstowe F boats, a series of flying boats that were directly descended from the H-1.
The controls were somewhat awkward, as Curtiss was attempting to avoid copying the Wright control system. As a result the ailerons were set up so that only one would move at a time, using foot controls instead of the more standard system where both ailerons were controlled by a wheel, and moved in opposite directions. The H-1 used a wheel to control the rudder.
When it was completed the H-1 America was the largest flying boat that had ever been built.
The H-1 was completed by June 1914, given a naming ceremony on 22 June and underwent flight tests that revealed the need for hull sponsons to improve buoyancy near the bow, which tended to submerge as full power was applied. Tests with 2,200lb of sandbags onboard revealed that it couldn’t take off with enough fuel for the trans-Atlantic flight. A series of alterations were made in an attempt to solve this problem. Sponsons or side fins were added to the side of the forward planing area. Hydrofoils were installed, but they proved to be too effective and the hull lifted out of the water at 15mph, too slow for the flight controls to work. More power was added by installed a third engine on top of the upper centre-section of the wing, driving a tractor propeller. The three engined version made its made flight on 23 July 1914, and could take off at 6,203lb weight. However the extra weight of the engine and its associated stores was too much, and it was apparently soon removed.
The aircraft was ready to attempt the flight when the First World War broke out. A route had been selected, starting from St John’s, Newfoundland, with stops at Fayal and San Miguel in the Azores and in Portugal. The start date was set as 5 August 1914, and some of the ground crews were already in place. However on 4 August 1914 Britain declared war on Germany, and the flight was cancelled. Porte returned to Britain and despite his ill health rejoined the Royal Navy.
Porte convinced the Admiralty to purchase both examples of the H-1 (giving them the serial numbers 950 and 951). The British then ordered more aircraft, which were produced as the very similar H-4 ‘Small America’. This was followed by the H-12 ‘Large America’ and H-16 ‘Large America’ and the Felixstowe F boats.
The first H-1, no.950, was delivered to Felixstowe on 13 October 1914. It was originally powered by the standard pair of 90hp Curtiss OX engines.
The second H-1, no.951, was delivered to Felixstowe on 25 November 1914. It was used in a series of experiments. By 1 October 1915 it had been give two 125hp Anzanis engines. Early in 1916 it was used to test the installation of a Davis recoilless gun which was mounted in an improvised position in the centre section of the upper wing! Test flights with the gun installed were recorded on 24 January and 26 January, with a gunner in place on the first flight. The H-1 could carry the extra load, but the weight of the gun and gunner and the extra air resistance it created made the aircraft unstable. No.951 was deleted from charge on 2 May 1916.
The H-1 and H-4 didn’t live up to expectations. Although they performed well in the air, their hulls were found to be rather too fragile for the North Sea, and they struggled to take off with a full military load. Porte began work on a new hull, eventually producing the Felixstowe F.1. This combined the original Curtiss wings with a new hull designed by Porte, and was a great improvement on the H-4. Only one prototype was produced, before work moved onto the F.2. This used the wings from a new Curtiss aircraft, give the designation H.8 by the RNAS. Once again the H.8 proved disappointing, and Porte combined its wings with a new hull to produce the Felixstowe F.2. The H-8 was followed by the Curtiss H-12, some of which served in their original configuration, and by the Felixstowe F.2A, which used the F.2 hull and H-12 wings. The F.2A was the first production version of the famous Felixstowe F boats, and was followed by the larger but less agile F.3 and the post-war F.5. In American Curtiss produced the F.2A as the H-16, while the British F.5 was modified to become the Naval Aircraft Factory/ Curtiss F-5L.
Engine: Two Curtiss OX engines (as built)
Power: 90hp each
Span: 74ft (upper), 46ft (lower)
Length: 37ft 6in
Empty weight: 3,000lb
Gross weight: 5,000lb
Maximum take-off weight:
Max speed: 65mph
Range: 1,100 miles