Blackburn G.P. from the front-right |
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The Blackburn G.P. was a general purpose seaplane designed in 1915 and which didn’t enter production, but which did lead to the land based Blackburn Kangaroo.
Blackburn’s previous design had been the unusual twin fuselage Blackburn T.B., designed as an anti-Zeppelin aircraft but an unsuccessful design. As a result Blackburn decided to produce a more conventional design for their next aircraft. This was the Blackburn G.P. or General Purpose, a twin engined three man seaplane intended for use as a long range anti-submarine patrol bomber.
The G.P. had a long slim fuselage with a small cross-section. The wings used a modified RAF 3 section. The upper wing was much longer than the lower wing, as on the T.B. The wings could fold back, reducing its width from nearly 75ft to 27ft 10in. Power came from two water cooled engines carried in nacelles on the lower wing. It had a large twin ruddered biplane tail unit. The two pontoons of the float undercarriage were carried under the engines, putting them unusually far apart. The pontoons were divided into twelve watertight compartments.
Two prototypes of the G.P. were built.
The first (serial number 1415) appeared in July 1916. It was powered by two 150hp Sunbeam Nubian engines rotating in opposite directions, each powering a four bladed propeller and with a vertical radiator block clamped to struts at the rear of the nacelle. It carried a crew of three, all in open cockpits, The bomb-aimer/ gunner was in the nose. The pilot was just in front of the wing centre section. The rear gunner was just behind the wings. A bomb sight was carried on the outside of the starboard side of the forward cockpit. It was armed with two Scarff mounted Lewis guns and could carry four 230lb bombs under the wings or a single torpedo under the fuselage. However this aircraft probably never carried a torpedo. The aircraft was sent to the Isle of Grain for tests, where it made its maiden flight in July 1916. It was then moored in rough seas for several days to test its robustness which appears to have ended its active career.
The second (serial number 1416) was completed late in 1916. It was powered by two 190hp Rolls Royce Falcon engines, again rotating in opposite directions. It had the same radiators as the first aircraft, and four bladed propellers. It used heavier gauge metal fittings that the first aircraft making it stronger. It had ailerons on the upper and lower wings. This aircraft made its maiden flight on the Humber at Brough late in 1916, in a old winter when there was drift ice on the river. The first flight was a success but getting the aircraft back on show was difficult. It then went to the Great Yarmouth Air Station for service trials. No orders followed for the seaplane G.P., but a landplane version was ordered as the Blackburn Kangaroo.
Engine: Two Sunbeam Nubian or Two Rolls Royce engines
Power: 150hp each or 190hp each
Crew: 3
Span: 74ft 10.25in (upper)
Length: 46 ft 0in
Height: 16ft 10in
Tare weight: 5,840lb (Rolls-Royce)
All-up weight: 8,600lb (Rolls-Royce), 8,100lb (Sunbeam)
Maximum take-off weight:
Max speed: 97mph at sea level (Rolls Royce)
Climb Rate: 10min to 5,000ft (Rolls Royce)
Service ceiling: 11,000ft (Rolls Royce)
Endurance: 8 hours (Rolls Royce)
Armament:
Bomb load:
Blackburn G.P. from the left