G.Duval British Flying-Boats and Amphibians 1909-1952 (Putnam)
Norman Thompson N.1B (1917)
The Air Board Specification N.1B called for a high-performance single-engined flying-boat of the fighting scout category. Several companies produced designs in accordance with this specification in the last two years of the war, including Norman Thompson.
The Norman Thompson N.1B, built in early 1917, retained several features of earlier designs, notably the boat-built hull with the characteristic narrow after-part, with the wing-tip floats attached directly to the undersurface of the lower wing, but the usual dorsal fin was replaced by a more normal fin and rudder of generous area, and the machine was smaller than its predecessors. The crew of two were housed in separate open cockpits, and the wings were arranged to fold forward. The machine was powered by a 200 h.p. Hispano-Suiza pusher engine, driving a four-bladed propeller, a portion of the upper wing trailing edge being cut away to clear the propeller. Launched in September 1917, the N.1B performed well on initial test flights, but on its service trials at R.N.A.S. Isle of Grain its performance was not judged to show any great advance on existing types, and it was not adopted.
Power Plant: One 200 h.p. Hispano-Suiza
Span: 34 feet 3 inches
Folded - 13 feet 2 inches
Length: 26 feet 5 inches
Folded - 32 feet 8 inches
Weight Loaded: 2,673 pounds
Total Area: 357 square feet
Max. Speed: 93 m.p.h.
Endurance: 3 1/2 hours
Armament: One free-mounted .303-inch Lewis gun
J.Bruce British Aeroplanes 1914-1918 (Putnam)
Norman Thompson N.1B
EARLY in 1917 work began on the contruction of a small two-seat flying-boat which was intended to be a high-performance fighting machine. In the Norman Thompson works it was known as the T.N.T., or Tandem Norman Thompson, in view of its seating arrangement; as an aircraft it fell into the Admiralty category N.1B.
The T.N.T. was a remarkably compact little machine in which considerable attention was paid to detail in order to reduce drag. The hull was a boat-built structure with two open cockpits in the deep forebody. The two-bay wings were unusual (on a flying-boat of that period) in two respects: they were of equal span, and ailerons were fitted to upper and lower wings. The ailerons were originally connected by light struts, but these were replaced by cables. Interplane bracing was by cables; the duplicated flying wires were carefully faired together. The wings were arranged to fold forwards, as on the A.D. Flying Boat.
The fin and rudder assembly were quite different in appearance from any other Norman Thompson design, for they were of comparatively high aspect-ratio. The base of the rudder was plywood-covered.
Power was provided by a 200 h.p. Hispano-Suiza engine which drove a four-bladed pusher airscrew. The trailing portion of the upper wing was cut away to allow the airscrew to revolve.
The Norman Thompson N.1B was launched in September, 1917, and performed well. The machine underwent makers’ trials until the end of the year, when it was turned over to the R.N.A.S. at the Isle of Grain for Service trials. The Norman Thompson company were optimistic about the outcome, because they claimed to have achieved a speed of 108 m.p.h. and a climb of 20,000 feet in 18 1/5 minutes with the N.1B: these were quite prodigious performances for a flying-boat at that time.
It seems doubtful that these results could have been obtained with a worthwhile load, for the official test figures fell a long way short of them. In particular, it was obvious that the machine could never have reached 20,000 feet on its official trial.
The N.1B was not officially adopted, presumably because its performance did not represent much of an advance over existing types.
Manufacturers: The Norman Thompson Flight Co., Ltd., Bognor Regis, Sussex.
Power: 200 h.p. Hispano-Suiza.
Dimensions: Span: 34 ft 3 in. (folded, 13 ft 2 in.). Length: 26 ft 5 in. (folded, 32 ft 8 in.). Height: 9 ft 7 in.
Areas: Wings: 357 sq ft.
Weights and Performance: No. of Trial Report: N.M. 173. Date of Trial Report: May 18th, 1918. Weight empty: 1,895 lb. Military load: 20 lb. Crew: 360 lb. Fuel and oil: 398 lb. Loaded: 2,673 lb. Maximum speed at 2,000 ft: 93 m.p.h.; at 6,500 ft: 92 m.p.h.; at 10,000 ft: 86-5 m.p.h. Climb to 2,000 ft: 3 min 30 sec; to 6,500 ft: 14 min 20 sec; to 10,000 ft: 27 min 35 sec. Service ceiling: 12,600 ft. Endurance: 3 1/2 hours at 6,000 ft.
Armament: Uncertain. Presumably one Lewis machine-gun fired by the observer.
Serial Number: N.37.