Only two aircraft manufacturers produced tenders to match the 3/20 specification for a single-seat deck-landing torpedo-carrier. The first proposal was a modified Dart from Blackburns, one of the traditional manufacturers of naval aircraft, and the second proposal was the Type T Hanley from Handley Page.
The first of three Hanley prototypes, N143, flew on 3rd March 1922, powered by a 450 hp Napier Lion engine, the next consecutive serial numbers, N144 and N145, being allocated to the Mk II and Mk III proto types.
The Hanley was the first Handley Page aircraft to be designed specifically to incorporate slats, this high-lift feature being particularly useful on aircraft carriers, with their short decks. The slightly swept two-bay wing employed fixed full-span slats on both leading edges, but trailing edge flaps were not fitted. The wings folded to decrease the parking space required in the carriers hangars. A single Mk 8 or 9 torpedo was carried, slung between the well-braced undercarriage legs.
Neither of the two types proposed was ordered and the specification was cancelled by the 32/22 specification, for which the Blackburn Dart Mk II was ordered. N143 was exhibited by Handley Page at the Gothenburg Aircraft Exhibition, Sweden, in July 1923.