In retrospect, the Handley Page H.P.50 Heyford had the appearance of something that only a mother (or perhaps designer) could love, its heavy-looking biplane structure and spatted main landing gear units suggesting low speed or inefficiency. This impression was heightened by the fact that the fuselage was mounted to the upper wing, strut bracing filling a large gap between the fuselage and lower wing. This layout had a purpose, of course, the lower wing centre-section being of almost double the normal aerofoil thickness to allow bombs to be stowed internally, and brought close to the ground to speed the business of re-arming after a bombing sortie. Other features of the configuration included wings of basic metal structure with fabric covering, a fuselage which was half metal- and half fabric-covered, accommodation for a crew of four, robust tailwheel landing gear, and a braced tailplane carrying twin fins and rudders. Power was provided by two Rolls-Royce Kestrel engines, mounted in nacelles beneath the upper wing, outboard of the fuselage and directly above the main landing gear units. The armament had one more unusual feature to add to the appearance of the Heyford, one of its three defensive machine-guns being mounted in a ventral 'dustbin' turret that could be lowered beneath the fuselage, aft of the wing.
The prototype H.P.38 was flown for the first time during June 1930, and successful service testing resulted in the type being ordered, initially as the Heyford Mk I. A total of 124 had been supplied to the RAF by the time that production ended in July 1936, these comprising 15 Heyford Mk I, 23 Heyford Mk IA, 16 Heyford Mk II and 70 Heyford Mk III aircraft; they differed primarily in installed powerplant. Entering service first with No. 99 Squadron at Upper Heyford, Oxon, they eventually equipped also Nos 7, 9, 10, 38, 78, 97, 102, 148, 149 and 166 Squadrons until the last of them were displaced by Vickers Wellingtons in 1939. However, they continued in use for some time, especially in training units, until finally declared obsolete in July 1941 as the last biplane bomber to serve with the RAF.