page_title: Blackburn Dart
section_title: Design and development
hierarchical_section_title: Blackburn Dart / Design and development
caption_attribution_description: English: Blackburn T.2 Dart, serial N955?, probably N9557 as this was at Martlesham in early 1925. Incorrectly identified as N139, the first Swift, in the source book.
context_page_description: The Blackburn Dart was a British carrier-based torpedo bomber biplane, manufactured by Blackburn Aircraft, which first flew in 1921. The Dart was the standard single-seat torpedo bomber used by the Fleet Air Arm from 1923 until 1933. A modified variant was also sold to Greece, where they served with the Greek Navy.
context_section_description: In 1919, Blackburn commenced the design of a private venture, carrier-based torpedo-bomber to replace the Sopwith Cuckoos which were the existing torpedo bombers flying from the Royal Navy's carriers. The Blackburn aircraft, the product of their chief designer, Major Frank Arnold Bumpus, was named T.1 Swift.  Although mainly conventional, the large biplane featured two-bay, equal-span wings that were staggered and could fold for storage aboard ship.  The wing centre section structure was steel with wooden outer sections, all fabric covered. Ailerons were mounted on all four wings. The fuselage was mounted on the lower wing, and also consisted of a metal structure with fabric covering. The tail unit had a braced tailplane and fin with a balanced rudder. The divided landing gear had mainwheels on oleo legs that allowed the fitting of a standard torpedo below the fuselage.
  The prototype Swift first flew in September 1920, almost crashing owing to a miscalculated centre of gravity. This was resolved by sweeping back the wings, while a revised rudder was fitted to improve directional control. Following this, the Swift proved satisfactory, and an order was placed against Specification 3/20 for a further three aircraft for service trials. These were renamed the Blackburn Dart.
  The Dart was powered by either a Napier Lion IIB or V engine that was mounted with a thrustline angled upward; the fuselage also dropped sharply downwards from the cockpit.
  The prototype Dart was first flown in October 1921, and despite its size handled well, exhibiting a remarkable 43 mph (69 km/h) stalling speed. 
  An export model of the Dart retained the name Swift and used the 450 hp (340 kW) Napier Lion engine. Seven were built as the Swift Mk II, two for the Japanese Navy, three for the Spanish Navy, and two for the United States Navy. The U.S. Navy aircraft were designated Swift F by Blackburn and Blackburn BST-1 by the U.S. Navy but following competitive trials in 1921, the U.S. Navy decided not to proceed with an order and purchased the Douglas DT-2 instead.
caption: Dart at Martlesham Heath
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