De Havilland DH.54 Highclere

The de Havilland DH.54 Highclere was a single-engined biplane airliner designed to replace the DH.34, built to Air Ministry specification 40/22 as a larger version of that successful aircraft. Compared with the DH.34 its passenger complement rose from nine to twelve, its all-up weight by 56 percent and its wing area by 70 percent, and full-span flaps were fitted in response to criticism of the earlier type's high landing speed. For safety over water the undercarriage could be jettisoned and the fuselage was watertight. A 650 hp Rolls-Royce Condor IIIA engine drove a four-bladed propeller. It was first flown by H.S. Broad on 18 June 1925 and received its certificate of airworthiness on 23 April 1926, but Imperial Airways had decided to carry passengers only in multi-engined types. The sole aircraft was used for experimental work and as a freighter before a hangar collapsed on it in heavy snow at Croydon on 1 February 1927.