Blackburn Ripon

The Blackburn T.5 Ripon was a carrier-based torpedo bomber and reconnaissance biplane designed and produced by the British aircraft manufacturer Blackburn Aircraft. It was the basis for both the license-produced Mitsubishi B2M and the improved Blackburn Baffin.

The Ripon was designed as a successor to the Blackburn Dart torpedo bomber as well as a long-range reconnaissance aircraft to fulfil Air Ministry Specification 21/23. The first prototype made its maiden flight on 17 April 1926, it was subsequently redesigned with a more effective engine installation, an enlarged rudder and increased wing sweepback. It was originally ordered into production for the Fleet Air Arm (FAA), which primarily operated the type as a torpedo bomber.

The Ripon was operated by the FAA between 1930 and 1935, after which point it was withdrawn in favour of the Blackburn Baffin, which was an improved derivative of the Ripon. It was also produced overseas in Finland; many of the Ripons in service with the Finnish Air Force saw extensive use in both the Winter War and the Continuation War, typically flying nighttime reconnaissance missions.

The origins of the Ripon can be traced back to the mid-1920s and the issuing of Air Ministry Specification 21/23, which sought a replacement for the Fleet Air Arm's (FAA) single-seat Dart that could operate both as a torpedo bomber and a reconnaissance aircraft. It was stipulated that it should have a two-man crew, comprising a pilot and navigator/gunner to facilitate long-range reconnaissance missions; for the same reason, the aircraft was to have a maximum endurance of at least 12 hours. A further requirement was that it should have an interchangeable undercarriage between wheeled and float-equipped configurations, facilitating its operation from both land and sea.

Blackburn begin work on its response to the specification during 1925, directed by F. A. Bumpus. The resulting aircraft, which was designed around the Napier Lion V engine, drew heavily on the preceding Blackburn Velos coastal defence seaplane, having a broadly similar structure with the exception of its use of single-bay wings and the anhedral on the bottom central section. The lower mainplane was of a slightly larger span than the lower, while an atypical feature in the form of a lower wing root fairing. A single Lewis gun fitted on a rotating mounting around the rear cockpit formed the defensive armament. Offensive armaments consisted of six 230lb bombs, or three 520lb bombs, or a single 18-inch torpedo.

A pair of prototypes were built. On 17 April 1926, the first prototype made its maiden flight in a landplane configuration, flown by P. W. S. Bulman. On 26 August of that year, the second prototype made its first flight as a seaplane, piloted by J. D. Rennie. During December 1926, the Marine Aircraft Experimental Establishment at Felixstowe commenced a formal evaluation of the aircraft. Initial trials against its competitors, the Handley Page Harrow and the Avro Buffalo, showed that none of the competitors were adequate, so the Ripon was redesigned with an improved engine installation, an enlarged rudder and increased sweepback on the wings. The revised aircraft was evaluated and declared to be the winner, after which Blackburn was awarded a production contract for the type.

The first production aircraft made its first flight in late 1927. Referred to as the Ripon II, design changes from the prototypes gave it a distinctly different appearance, such as its more pointy nose as a consequence of the new cowling and retractable radiators for engine cooling. The undercarriage had been drastically redesigned as well, featuring telescopic oleo struts fitted to the outboard ends of the bottoms centre front spar. Structurally the aircraft was largely unchanged and continued to conform with established Blackburn practices of the era, The gun ring was redesigned for a lower positioning, along with a slot in the rear decking for it to be locked into when not in use; the cockpit was also extended rearwards to house more apparatus.

On 15 May 1928, the first production aircraft made its public debut, performing a flying demonstration that included a practice torpedo deployment over the Humber along with some aerobatic manoeuvres in front of the assembled press. During 1928 and 1929, Blackburn received contracts for a combined 20 Ripon IIs. In early 1930, more substantial orders for 40 of the improved Ripon IIA were placed; this variant made greater use of duralumin in its wings and provided a mildly raised all-up weight. The production rate reached two aircraft per week around this time, which was facilitated by the subcontracting of some component manufacturing to the competing British aviation manufacturer Boulton Paul Aircraft.