The Blackburn Aircraft Company RB2 Sydney was a large, three-engine monoplane flying boat that was developed using as (a starting point) the hull lines of the successful Blackburn Iris
The Blackburn Sydney was a 100 ft wingspan monoplane with the wings being of all-metal construction with fabric covering. The wing was mounted on a pylon, providing propellor clearance above the fuselage for the central engine.
The type was offered against Specification R.5/27, which sought a long-range reconnaissance flying boat with five crew. The five crew roles were Captain, Second Pilot / Navigator, Bow-gunner / Bomb-aimer, Midships gunner / Wireless operator and Rear gunner / engineer. The two pilots sat side-by-side in an enclosed cockpit.
A single prototype (N241) was ordered, powered by three 525 hp Rolls-Royce Falcon XIIMS engines.
Because the type was considered to have strong potential as a commercial aircraft, Blackburn Aircraft designed a parallel civil variant, the Bristol Jupiter-powered Blackburn CB2 Nile. This was schemed around three crew / fourteen passengers and was intended for use on the route from Alexandria to Capetown. The Blackburn Nile was to be operated by a new airline Cobham-Blackburn Airlines.
Blackburn completed construction and furnishing of the fuselage for the Blackburn Nile but the project was abandoned following the formation of Imperial Airways, which was granted a monopoly on long-distance air services. The redundant and unfinished Blackburn Nile hull was subsequently decommissioned and used as a structural test specimen.
The Blackburn Sydney carried three defensive machine guns fitted in the bow, amidships and in tail positions. It s offensive armament comprised of two 550 lb or four 250 lb, bombs carried under the wings. Provision was also made for the carriage of two 1,850 lb Mk VIII or Mk X torpedoes. its maximum endurance was around 7.5 flying hours with a fuel capacity of 560 gallons contained in a tank in the wing pylon.
The Sydney prototype was initially painted silver and was first flown on 18th July 1930.
After three flights it was repainted into a grey scheme similar to that of the in-service Iris II aircraft.
Tests at the Blackburn Works at Brough were completed at the end of November 1930 prior to it being delivered to the Marine Aircraft Experimental Establishment (MAEE) at Felixstowe on 9th December of that year.
The aircraft suffered from reliability problems and was eventually struck off RAF charge during 1934.
Variants & Number Built
|Blackburn RB2 Sydney||One only (N241)|
|Blackburn CB2 Nile||Hull only completed and used as a structural test article in 1935|
|Powerplant||Three 525 hp Rolls-Royce Falcon XIIMS engines|
|Span||100 ft 0 in|
|Maximum Weight||23,350 lb|
|Capacity & Armament||Five crew; three defensive Lewis guns, up to 1,100 lb bomb load , provision for carriage of two 1,850 lb torpedoes.|
|Maximum Speed||117 mph sea level, 123 mph at 5,000 ft|
|Econ cruise speed||100 mph|
|Endurance||Maximum 7.5 hours|