Blackburn Blackburn from the left |
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The Blackburn Blackburn was a reconnaissance and gunnery fire control aircraft that served with the Fleet Air Arm from the mid 1920s to the early 1930s, and was a generally successful design despite being a rather ugly aircraft.
The Blackburn was developed in response to Specification 3/21 which called for a deck landing biplane to serve on reconnaissance and gunnery fire control duties. The Blackburn was designed by Major F. A. Bumpus, who decided to use as many components from the Blackburn Dart torpedo bomber so that both could use the same spare parts. The Blackburn thus used the same two bay biplane mainplanes, tail unit and control surfaces as the Dart (apart from the rudder). The central part of the fuselage was built around a network of steel tubes, fitting into joints that had been machined down from a solid block of metal. The rear part of the fuselage was of semi-monocoque construction. It was powered by a 450hp Napier Lion IIB twelve cylinder water cooled engine, mounted as a detachable power unit so any other similar engine could be used. The engine bay was similar to that of the Dart.
The most distinctive feature of the Blackburn was the shape of the fuselage. In order to fit in the crew of three it was much taller than that of the Dart. On the prototype and Blackburn Mk I filled the entire gap between the wings, an idea taken from the Swift IV (the Dart was the production version of the Swift I) and from a Blackburn ten seat civil airliner. It wasn’t very wide, giving the aircraft an usually tall but narrow fuselage. The pilot’s cockpit was at the top of the fuselage, in a cutout in the upper wing. The engine cowling sloped down steeply to give him a better view, important for carrier landings. The wireless-operator/ gunner and navigator/ observer’s positions were lower down, inside the fuselage. The wireless-operator/ gunner was at the forward end of the fuselage, with a folding table. The navigator/ observer was towards the rear of the wing, with an open section at the back of his position to allow him to use the sextant or range finder or take pictures. It carried two guns – one fixed forward firing Vickers gun on the left side of the fuselage below the pilot and one flexibly mounted Lewis gun behind the navigator’s position. It could carry 90 gallons of fuel, split between a main saddle tank under the centre section and two streamlined tanks on top of the upper wing. The prototype had a wheel-and-axle type undercarriage, with extra struts to provide more strength during carrier landings.
The three prototypes of the Blackburn were built alongside the first production Darts in 1922. The first prototype (N150) was tested at Brough, where Robert Blackburn was given his first ever flight! Handling tests at the Aeroplane and Armament Experimental Establishment at Martleshem were completed by 12 August 1922. On 19 August the prototype few to Gosport for deck landing trials on the carrier Argus. These began on 23 August.
The second prototype (N151) went to Martlesham on 5 September 1922 for performance tests. However it suffered from fuel surging and needed new undercarriage oleos, so the trials weren’t completed until 20 January 1923. The aircraft returned to Blackburn at Brough on 24 January. Martlesham liked the undercarriage but not the ‘draughty and uncomfortable’ pilot’s cockpit. At some point they tested the aircraft with a Dart rudder and recommended using that instead of the original design, in order to simply the spares situation even move. N151 was later used as a trials aircraft, before being flown from Brough to Farnborough on 19 September 1924.
The third prototype (N152) was forced to land in a field at Lowestoft while on its way from Blackburn at Brough to Martlesham on 30 September 1922. While on the ground at Lowestoft it was photographed by a local, and the pictures ended up in The Aeroplane of 15 November 1922. N151 and N152 were then used to investigate the fuel surge problem, and it was found that this could be cured by building up extra air pressure in the fuel tank before take-off. N152 was then destroyed in a hanger fire at Martlesham in October 1922.
The Blackburn was ordered into production in 1922. The first production aircraft were delivered to Gosport in April 1923, before moving to Farnborough to have short range radios installed.
Despite its rather ungainly appearance the Blackburn was a satisfactory design. It could take off in as little as 60ft from a carrier steaming into the wind,
Two flights in the Fleet Air Arm were equipped with the Blackburn.
No.422 Fleet Spotter Flight was given the Mk I in 1923, for service on HMS Eagle in the Mediterranean and from Hal Far on Malta. Many of these aircraft later returned to Brough to be brought up to Mk II standard. In 1929 No.422 was renumbered as No.450 Fleet Spotter Reconnaissance Flight, and served on HMS Argus on the China Station. She then moved to HMS Courageous in the Mediterranean in 1929-31.
No.420 Fleet Spotter Flight converted to the Mk II from the Westland Walrus in 1926 at Gosport, and then moved to HMS Furious to serve with the Home Fleet from 1926-28. In 1929 No.420 was renumbered as No. 449 Fleet Spotter Reconnaissance Flight and served on HMS Courageous in the Mediterranean in 1929-31. The flight took part in exercises off the Isle of Wight in September 1930.
In 1933 all of the Blackburn Blackburns in the fleet were replaced by the Fairey IIIF and they were declared obsolete in March 1933.
A number of Blackburns were converted into dual control deck landing trainers, for use at No.1 Flying Training School at Leuchars. A wider pilot’s cockpit was built, to allow the instructor and pupil to sit side by side. The change rather spoilt its limited performance, and it needed up to 600 yards to take off!
Two Mk Is were converted into twin-float Float Planes at Brough. Trials showed that although she flew perfectly well with the twin floats, she was unsuitable for use as a seaplane.
Work on a replacement for the Blackburn began as it was entering service. The resulting Blackburn Airedale had a central fuselage very similar to that of the Blackburn, with the same layout of crew compartments, but with an odd looking monoplane wing. Two prototypes were built but it never entered production.
Blackburn R.1 Blackburn Mk I
Production aircraft were all given large portholes in the side to let light into the large but otherwise dark interior. The original three prototypes were followed by three production orders. Twelve were ordered in 1922 (N9579-N9590), six in 1923 (N9681-N9686) and twelve in June 1924 (N9824-N9835)
The third production aircraft, N9581, went to Martlesham on 28 April 1923 for acceptance trials, which lasted in 23 June. On 30 June it was then displayed in the New Types Part at the Hendon RAF Display.
The Twelve Mk Is in the first production order (N9579-N9590) were built with the Dart style split undercarriage, possibly to allow them to be used to carry a torpedo. The remaining Mk Is had the axle type undercarriage.
Blackburn R.1A Blackburn Mk II
A series of orders for 29 Mk IIs, built to Specification 11/23 were placed between January 1925 and December 1926 (N9989-N9989, S1046-S1057 and S1154-S1158). The main visual difference on the Mk II was that the upper wing was raised by 22.5in to create a gap between the top of the fuselage and the wing. This was done because the Mk I suffered from elevator blanketing. It was powered by the Napier Lion V. The structure was cleaned up and the wing fuel tanks were removed. A new cross axle undercarriage was installed.
Mk I
Engine: Napier Lion IIB
Power: 450hp
Crew: 3
Span: 45ft 6.5in
Length: 36ft 2in
Height: 12ft 6in
Tare weight: 3,929lb
All-up weight: 5,962
Max speed: 122mph at 3,000ft; 112.5mph at 10,000ft
Climb Rate: 690ft/ min at take off, 566ft/ min at 3,000ft, 224ft/ min at 10,000ft
Max height reached in trials: 13,450ft in 49 minutes
Service ceiling: 12,950
Endurance: 4hr 15min at 103.5mph
Bomb load: Two machine guns
Mk II
Engine: Napier Lion V
Power: 465hp
Crew: 3
Span: 45ft 6.5in
Length: 36ft 2in
Height: 14ft 4.5in