The DH.9 entered service with No 103 Squadron RFC at Old Sarum, Wiltshire, in December 1917, and became operational with No 6 Squadron in France in the following March. Fitted originally with a Beardmore engine, the
aircraft proved to be underpowered and its performance was inferior to that of the DH.4, on which its design was based and which it was intended to replace. Engine failures were rife, and fuel consumption above 3050m was a
staggering 15 gallons per hour. Once the DH.9 was re-engined with the Packard Liberty motor, however, it became an entirely different aircraft.
RAF squadrons in France began re-arming with the new variant -
designated DH.9A - in August 1918, and the type played an important part in the Allied bombing offensive until the end of World War I. Afterwards, RAF DH.9A squadrons performed a vital policing role in the British-
controlled territories in the Middle East and India throughout the 1920s. Many DH.9s were converted for civilian air transport use.
