Blackburn T.1 Swift, T.2 Dart and T.3 Velos

Single seat private venture carrier based torpedo bomber, designed by Major Frank Arnold Bumpus. Of conventional construction, the large biplane featured two-bay, equal-span wings that were staggered and could fold for storage aboard ship. The fuselage was built in three sections : the engine mounting with cowling, etc., followed by the fuselage centre portion, incorporating the cockpits, undercarriage attachments, etc., along with the wing centre section. Both of these were of fabric covered, steel-tube construction, the upper longerons sloping down ahead of the pilot’s cockpit to improve the forward view for deck-landing. The rear fuselage was a fabric covered wooden structure, braced with tie-rods. The outer wings were also a fabric covered wooden construction, with spruce spars spindled out from the solid to form an I-section. Ailerons were mounted on all four wings. 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 fuel tank was located within the fuselage, just aft of the engine fireproof bulkhead. One 450 h.p. Napier Lion IB powerplant.

As Mk.I with repositioned radiator, modified cowling, silencer and redesigned tail surfaces, slightly enlarged and fitted with horn balances.

Mk.II as delivered to U.S. Navy for evaluation - would have been designated the BST-1 if ordered.

Swift derivative to meet the requirements of Specification 3/20. As the Swift, but with reduced span and the claw arrestor gear that had been fitted experimentally to the Swift prototype fitted as standard. One 450 h.p. Napier Lion IIB or (later aircraft) 465 h.p. Napier Lion V powerplant.

T.2 Dart Specification
Span	Length	Height	Wing Area	Empty Wt	Max AUW	Cruise Speed	Maximum Speed	Range	Service Ceiling
45 ft 6 in	35 ft 4.5 in	12 ft 11 in	654 sq ft	3599 lb	6383 lb	100 mph/ 87 kn	107 mph/ 93 kn	410 mi	12700 ft
13.87 m	10.78 m	3.94 m	60.76 m2	1632 kg	2895 kg	161 km/h	172 km/h	660 km	3871 m

Two seat Dart seaplane/landplane derivative to meet a Greek requirement for a coastal defence aircraft. The Velos differed from the standard Dart in having a two-seat cockpit with a rear-mounted .303 in Lewis Gun, an increased weapons load with four 230 lb bombs mounted under the wings and provisions to fly as either a seaplane with floats or with a conventional undercarriage. One 465 h.p. Napier Lion V powerplant.

Greek built variant featuring raised gunners position.