First flown in October 1921, its performance quickly impressed officials and a production order was issued to Blackburn on behalf of the FAA.

Greece opted to procure a modified seaplane variant of the aircraft, the Blackburn Velos, which was operated by the Greek Navy as a torpedo bomber.

Around this time, the Air Ministry had reissued its requirement for a new carrier-based torpedo-bomber that would replace the Sopwith Cuckoo, the standard torpedo bomber of the era being flown from the aircraft carriers of the Royal Navy.

This structure provided sufficient strength to withstand the high stresses of carrier operations and carry a heavy concentrated payload, while also being relatively easy to maintain and repair.

The divided landing gear had main wheels on shock absorber (oleo) legs that allowed the fitting of a standard torpedo below the fuselage.

[5][6] A novelty was the detachable mounting for the engine, which facilitated its replacement as a complete power unit and enabled its swapping in a matter of hours.

[3] By July 1920, the prototype Swift was sufficiently complete as to permit it to go on be static display to the public at the Olympia Aero Show but without a radiator or controls.

[1] The aircraft had already been placed on the British Government's secret list, which meant that it could only be displayed without specialised naval equipment, such as its torpedo release apparatus.

Following this modification, the Swift proved largely satisfactory in flight; on 23 December 1920, it was brought to RAF Martlesham Heath for performance trials by the Aeroplane and Armament Experimental Establishment.

[8] Shortly thereafter, the type's first deck landing was performed by the Canadian pilot Gerald Boyce onboard HMS Argus.

[8] Having suitably impressed officials, Blackburn received an order for three aircraft to conduct service trials as per Air Ministry Specification 3/20.

[9][10] The Dart had its wingspan reduced by 2 ft 11 in (0.89 m), which brought the twin tips closer to the outboard interplane struts, was the most visually distinctive change.

[11] A series of competitive trials against the Handley Page Hanley were conducted at Gosport, during which the Dart emerged as the victor and became the new standard torpedo bomber of the Fleet Air Arm.

According to the aviation author Audrey Jackson, the Dart played an important role in the FAA's development and perfection of techniques for torpedo-bombing.

[16] Three Darts were converted into two-seat seaplanes to provide advanced training at Blackburn's RAF Reserve School on the River Humber between 1925 and 1929.