Felixstowe F.5

The Felixstowe F.5 was a British First World War flying boat designed by Lieutenant Commander John Cyril Porte RN of the Seaplane Experimental Station, Felixstowe.
Design and development.
Porte designed a better hull for the larger Curtiss H-12 flying boat, resulting in the Felixstowe F.2A, which was greatly superior to the original Curtiss boat. This entered production and service as a patrol aircraft. In February 1917, the first prototype of the Felixstowe F.3 was flown. This was larger and heavier than the F.2, giving it greater range and a heavier bomb load but inferior manoeuvrability. The Felixstowe F.5 was intended to combine the good qualities of the F.2 and F.3, with the prototype (N90) first flying in November 1917. The prototype showed superior qualities to its predecessors but the production version was modified to make extensive use of components from the F.3, in order to ease production, giving a lower performance than either the F.2A or F.3.
Operational history.
The F.5 did not enter service until after the end of the First World War, but replaced the earlier Felixstowe boats (together with the Curtiss machines), to serve as the Royal Air Force's (RAF) standard flying boat until being replaced by the Supermarine Southampton in 1925.
Variants.
Saunders hull.
S. E. Saunders were awarded a contract in 1922 to investigate the merits of a tunnel type wooden hull in comparison with an all-metal hull built by Short Brothers.
The new 'hollow bottom' ventilated hull was patented by Saunders and fitted to F.5 (N178), the aircraft delivered to the Marine Aircraft Experimental Establishment in September 1924, however trials were brief and it was dismantled and scrapped by mid 1925. The Short Brothers' design proved the merit of metal hulls.
Short S.2.
In 1924 the Air Ministry invited tenders for two hulls of modern design to suit the wings and tail surfaces of the F.5. Short Brothers submitted a proposal for an all-metal hull developed from the Short Silver Streak.
Built of duralumin, then a largely untried and untrusted material, the aircraft was first flown on 5 January 1925 and delivered to the Marine Aircraft Experimental Establishment at Felixstowe on 14 March where it was subjected to a series of strenuous tests, including dropping the aircraft onto the water by stalling it at a height of 30 ft (9 m): the aircraft withstood all trials, and after a year an inspection revealed only negligible corrosion.
Thereafter, all Short flying boats were of metal construction and other manufacturers pursued the same practice following development of their own construction methods. The trials succeeded in overcoming official resistance to the use of duralumin, and led to the order for the prototype Short Singapore (N179).
Operators.
 – (Post-war)
References.
Notes
Bibliography