C.Barnes Bristol Aircraft since 1910 (Putnam)
The Bristol T.T.A. and F.3A
When Frank Barnwell returned to Filton in August 1915 he sought a technical assistant to work with him on new projects. He interviewed Leslie G. Frise, who had just graduated from Bristol University, and persuaded him to resign his R.N.A.S. commission to join the Company; together in September 1915 they laid out the preliminary design of a twin-engined local defence two-seater to a War Office requirement. Four R.A.F.4a engines of 150 h.p. were promised for two aircraft, and the aim was to design a compact biplane with a fuselage of the minimum size that would accommodate a pilot and gunner, giving the latter a maximum field of fire. Although both the crew could not be given equally good fields of vision, the pilot's location aft of the trailing edge gave a good view forward and downward. The gunner in the nose had an unobstructed field of fire in the forward hemisphere for two free-mounted Lewis guns and had five spare drums of ammunition, also a vertical camera. The pilot had a single Lewis gun firing aft, with three spare drums. Dual controls were fitted for emergency use only, with pedals in the front cockpit because the nose was too narrow for a normal rudder bar. The wings were of equal span and designed to fold back. Two sets of ailerons were designed, those actually constructed being of high aspect ratio. The tail unit comprised a single balanced rudder and flat tailplane of Scout D shape. The engine nacelles were midway between the wings and their rear fairings enclosed the oil and gravity fuel tanks. Below each nacelle was a small two-wheeled chassis of low drag, while the fuselage was protected by a fixed skid under the nose and a sprung tail-skid. The biplane, designated T.T. (Twin Tractor), promised to fulfil all the requirements, and was smaller than the F.E.4 designed at Farnborough to do the same job, which had a span of 75 ft.
After tendering, the Company was informed that all R.A.F.4a engines were earmarked for the B.E.12 and R.E.8 programmes, and that 160 h.p. or 120 h.p. Beardmores would be issued instead. At length the smaller engines materialised, and in January 1916 the amended design was finished as T.T.A., two prototypes being ordered on 15 February 1916 at a price, less engines, of ?2,000 each. These identical aircraft, Nos. 1375 and 1376 (7750 and 7751), were test flown and accepted on 26 April and 27 May, respectively, by Capt. Hooper, Commanding Officer of the R.F.C. Acceptance Park at Filton. The first T.T.A. was flown to Upavon on 11 May for trials by A.LD. pilots and achieved a top speed of 87 m.p.h., and an initial rate of climb of nearly 400 ft. per minute, which was better than the F.E.4's performance in spite of the reduced power available, but the design was adversely criticised on other grounds and not recommended for squadron service.
Concurrently with the building of the T.TA.'s the Admiralty released to the War Office a few 250 h.p. Rolls-Royce engines for experimental use, and the Company was invited to tender for an escort and anti-Zeppelin fighter using this power unit. Many firms submitted designs and Armstrong Whitworth, Bristol, Sopwith and Vickers all received orders for two prototypes each. The Bristol design, F.3A, was ordered on 16 May 1916 and sequence Nos. 1485 and 1486 were reserved, the corresponding R.F.C. serials being A612 and A613. The F.3A utilised many of the TTA.'s components, including wings, tail unit and rear fuselage with pilot's cockpit, but the contract was cancelled soon after being awarded, so it was never built. The landing gear was unorthodox and consisted of one T TA. chassis unit, suitably strengthened, under the fuselage with a small-wheeled outrigger under each wing-tip. Two gunners' nacelles were provided above the top wing, with a forward and a rearward gun in each, mounted on telescopic pillars swinging through 90 degrees to fire on the beam. Probably it was intended to install the Davis gun if this had developed satisfactorily. Duration of seven hours for night-fighting against Zeppelins was specified, but the project was abandoned as soon as reliable gun-synchronising gear became available.
SPECIFICATIONS AND DATA
Types: T.T.A. and F.3A.
Manufacturers: The British & Colonial Aeroplane Co. Ltd., Filton, Bristol
Type T.T.A. F.3A
Power Plant Two 120 hp Beardmore One 250 hp Rolls-Royce
Span 53 ft 6 in 53 ft 6 in
Length 39 ft 2 in 36 ft 5 in
Height 12 ft 6 in 12 ft 11 in
Wing Area 817 sq ft 817 sq ft
Empty Weight 3,820 lb 3,400 lb
All-up Weight 5,100 lb 5,300 lb
Maximum Speed 87 mph -
Accommodation 2 3
Production 2 nil (2 cancelled)
Sequence Nos. 1375, 1376 (1485 1486)
H.King Armament of British Aircraft (Putnam)
T.T.A. This large two-seat fighter was first flown in the same month (May 1916) as the Avro Pike and there can be little doubt that it was initially intended to have been similarly armed. The 'one large gun' which was on one occasion mentioned as an alternative to the two Lewis guns with which the T.T.A. is generally associated may well have been of the Hotchkiss type, by then becoming established in French service. The pilot sat behind the wings, from which position he could sec little and probably accomplish less, for he was responsible for a rearward-firing free Lewis gun. For this he had three spare 47-round drums. The gunner, remote in the nose, had five drums for his Lewis gun.
W.Green, G.Swanborough The Complete Book of Fighters
BRISTOL T.T.A. UK
Designed by Frank Barnwell assisted by Leslie G Frise, the T.T.A. (Twin Tractor Model A) was intended to meet a requirement for a two-seat twin-engined local defence fighter, the gunner in the nose having an unobstructed field of fire for two free-mounted 0.303-in (7,7-mm) Lewis guns. Dual controls were fitted and the intended power plant comprised two 150 hp R.A.F.4a engines. In the event, non-availability of these engines resulted in the installation of two 120 hp six-cylinder Beardmore water-cooled engines in the two prototypes ordered. The first T.T.A. was flown in April 1916, but displayed poor lateral control and was adversely criticised on the grounds of poor pilot view. As by this time synchronising mechanisms for guns were becoming available, no further development of this category of aircraft was pursued.
Max speed, 87 mph (140 km/h) at sea level.
Time to 6,000 ft (1830 m), 21 min.
Empty weight, 3,820 lb (1 733 kg).
Loaded weight, 5,100 lb (2 313 kg).
Span, 53 ft 6 in (16,30 m).
Length, 39 ft 2 in (11,94 m).
Height, 12 ft 6 in (3,81 m).
Wing area, 817 sq ft (75,90 m ).