Air Ministry Specification B.19/27 of 1927 was eventually fulfilled (more or less) by two competing products - the Handley Page Heyford and the Fairey Hendon. The requirement called for a heavy, twin-engined night-bomber capable of 115 mile per hour speeds while carrying a 1,546lb war load out to 920 miles. While the Hendon was officially declared the winner (beating out submissions from Avro, Bristol and Vickers), delays in the product forced the Air Ministry to also accept the Handley Page Heyford - the Heyford went on to be produced in greater numbers than the winning Hendon.
The Fairey Hendon offered the RAF their first all-metal, low-wing monoplane bomber (the Heyford was a biplane, the last such aircraft adopted by the service). Design work resulted in a true interwar design with a mix of modern qualities and those taken from a by-gone era of flight - open-air cockpits, fixed, spatted main landing gear legs, etc... Each wing was given an engine installation and the tail unit incorporated a twin-rudder approach. Internally, a steel tube framework was constructed and covered over in fabric. The crew number five and included a pilot, radioman/navigator and three dedicated machine gunners - single 7.7mm guns were fitted to a nose, dorsal and tail position. The bomb load totaled 1,660lb and held in a centrally-located bay.
The prototype aircraft was designated "K1695" and operated under the internal name of "Fairey Night Bomber" during a portion of its development. A first-flight was had on November 25th, 1930 over Heathrow and this example carried Bristol "Jupiter VIII" series air-cooled radial piston engines of 460 horsepower each. However, on a March 1931 test flight, the prototype crashed which severely hampered development - prompting officials to look at bringing the competing Handley Page Heyford to fruition. Heavily damaged, the prototype was rebuilt and now flew with 2 x Rolls Royce Kestrel VI engines in place of the Bristol fits seen earlier.
In this form, the bomber passed its testing phase and an order for fourteen of the type was formulated. As the prototype was recognized as "Hendon Mk.I", the production models became "Hendon Mk.II" and appeared from 1936 until 1937 (these finally featured enclosed crew positions). By this time attention had turned to the more modern Armstrong Whitworth Whitley heavy bomber then in development and set to outshine both the Hendon and Heyford in their roles. As such, an order for sixty Hendons was cancelled and these rerouted to the purchase of the Heyfords as interim measures.
No.38 Squadron became the sole operator of Hendons in November 1936, succeeding the Heyford stock. As with the Heyford, the Hendon was declared obsolete before World War 2 and were themselves succeeded by Vickers Wellington bombers from late-1938 onward. Formal retirement met the line in early 1939 at which point the Hendons joined the Heyfords as training / instructional instruments.