The forerunner of the Spartan Cruiser was the Mailplane, designed by Edgar Percival and built by Saunders-Roe as the Saro A.24 Mailplane, but redesignated the Spartan Mailplane before its first flight on 1 June 1931. In 1932 the single tailfin was replaced by a twin unit. Two passenger seats and windows, still missing here, were added and the aircraft was named Blackpool for a flight to Karachi by Neville Stack in June 1932. G-ABLI reportedly scrapped in February 1933.