Two generations of wooden aircraft: the Felixstowe F-5L, built by the Naval Aircraft Factory, next to the Mosquito B-35, modified to target tug TT-35.
The Felixstowe was at a British naval base (N.A.F.) to which Curtiss flying boats were shipped and subsequently modified under Lt John Cyril Porte, RN. Porte to have flown first attempt at a trans-Atlantic crossing, in Curtiss-Wanamaker Model H Boat, America. Boat built for Rodman Wanamaker to compete for $50,000 prize from the London Daily Mail for first such flight. Flight to have commemorated 100th anniversary of peace between US and UK. Crew was to consist of 1 British (Porte) and 1 US crew member, but Porte recalled to active duty upon Britain's entry into WWI. Flight never made. (In retrospect, proposed US pilot, George E. A. Hallett--later MAJ, USA (Ret)- -felt their chances would have been slim because of absence of engine carburetor heat; he attributed this as cause of later failures in attempted trans-Atlantic flights). Porte convinced of flying boat utility--especially for sub patrols and reconnaissance from British bases. As result, 1 Curtiss H-1 and 3 H-2s ordered. Additional 8 H-4s ordered from Aircraft Manufacturing Co. in UK (licensed by Curtiss). Jun 15, 12 more H-4s ordered, known as Small America. Curtiss eventually delivered 62. Porte experimented with first fewH-4s to incorporate features called for by increasing operational experience. Changes strictly empirical, chop-and-change. Steps added/ subtracted or moved fore/aft, sponsons added to increase beam, shapes variously modified, deadrise varied to meet shock-absorbing or spray conditions. H-4 became less Curtiss and more Porte--became Felixstowe F-1. Basically an H-4, had good service record. On the basis of information provided from these tests, Curtiss designed H-12, known as the Big America. By same process of changes, became F-2 and later evolved into F-3 and F-5. H- 4 was designed for weight carrying and seaworthiness. Had endurance of up to 17 hours, although at relatively low airspeeds of 40-60 mph. Gross weight 4650 pounds with 1400 pounds of useful load. Takeoff distance 1100- 2200 feet with lift-off at about 50 mph. Curtiss and Felixstowe designs set basic formula for all British maritime aircraft up to 1930s.