The Blackburn B-3 was one of three types ordered by the Air Ministry for evaluation as a torpedo-bomber against Specification M.1/30, which sought a replacement for the Blackburn Ripon.
Blackburn Aircraft, Handley Page and Vickers responded with prototypes being ordered from each company.
Of the two aircraft built by Blackburn, the first (S1640) was subject to the official contract and was known throughout its life as the M.1/30.
It comprised a pilot and observer/ gunner who were seated in tandem cockpits with the observer being able to access a prone bomb aiming position below the pilot’s cockpit floor. Construction was conventional, with a metal structure and fabric covering to both wings and fuselage. Unusually, the tailplane was mounted just above the top decking of the rear fuselage whilst the wings could be folded to the rear, being hinged around their rear spar attachments. A wide track undercarriage allowed for torpedo carriage beneath the fuselage and bomb racks were provided beneath the wings. It was powered by an 825 hp liquid-cooled Rolls-Royce Buzzard engine, driving a 15 ft diameter two blade propeller and flew for the first time at Brough on 8th March 1932.
After completion of Blackburn’s trials the M.1./30 was delivered to Martlesham Heath for official trials, commencing on 29th January 1933. Unfortunately, it suffered an accident on 30th June 1933 due to engine failure on take-off and was written off.
Meanwhile, Blackburn had decided to build a second prototype as a private venture, incorporating a number of improvements. This differed in having a metal semi-monocoque fuselage incorporating sealed compartments to provide buoyancy. It carried a Class B civil test registration (B-3) although it soon became known as the M.1/30A. It was flown for the first time on 24th February 1933.
Among the other changes introduced were a reduction in wing area of some 70 sq ft, achieved by reducing both the span and chord of the lower wings. The aircraft was also fitted with automatic slats and featured long-span ailerons that could also be lowered symmetrically to act as camber-changing flaps. A third cockpit was also introduced for a dedicated rear gunner whilst a sealed structural fuel compartment was also introduced within the fuselage ahead of the pilot.
Trials at Martlesham Heath commenced on 14th March 1933, where the type was condemned for having heavy controls and being overweight. The fuel filled fuselage compartment was also criticised although the sealed buoyancy compartments were regarded as favourable.
This resulted in the aircraft being taken on charge in May 1933 (as K3591) and in January 1934 it was transferred to the Marine Aircraft Experimental Establishment specifically for ditching trials. The aircraft was eventually salvaged after these trials and returned to the manufacturers for assessment of the effects of saltwater corrosion. Following this, the aircraft was sold as scrap.
Variants & Numbers Built
Two only: M.1/30 S1640, M.1/30A B-3 later taken on charge as K3591
|Powerplant||One 825 hp Rolls-Royce Buzzard IIIMS|
|Span||49 ft 6 in|
|Maximum Weight||10,393 lb|
|Capacity & Armament||Three crew; one forward-firing Vickers gun, rear MkIII Lewis gun in rear cockpit; One 1,900 lb Mk VIII or Mk X torpedo or equivalent (maximum 2,200lb) underwing bomb load|
|Maximum Speed||142 mph sea level; 130 mph 10,000 ft|
No Blackburn B-1 (M.1/30) aircraft survive.