In British service The prototype two seater flew in December 1915 and production deliveries started to reach the RNAS in February 1916. The
War Office had ordered the type for the RFC in March but because Sopwith's production capacity was contracted to the navy, the RFC orders had to be placed with Ruston Proctor and
Vickers. Sub-contract production from these manufacturers did not get into its stride until August. Since the
Battle of the Somme was planned for the end of June and with the RFC having a shortage of modern aircraft, it was agreed that a number of Sopwiths would be transferred from one service to the other, allowing
70 Squadron to reach the front by early July 1916 with Sopwith-built Strutters, originally intended for the Navy. At first, 70 Squadron did very well with their new aircraft. The period of German
ascendency known as the
Fokker scourge was over and the Strutter's long range and excellent armament enabled offensive patrolling deep into German-held territory. By the time
45 Squadron reached the front in October, the new
Albatros fighters were arriving at the . By January 1917, when
43 Squadron arrived in France, the Strutter was outclassed as a fighter; a more powerful Clerget 9B improved performance slightly but too late to reverse the situation. It was still a useful long-range reconnaissance aircraft when it could be provided with adequate fighter escort but was one of the types to suffer severely during "
Bloody April", 43 squadron alone suffering 35 casualties, from an officer establishment of 32. Like other early Sopwith types, the Strutter was very lightly built and its structure did not stand up very well to arduous war service. It was far too stable to make a good
dogfighter and the distance between the pilot and the observer's cockpits impeded their communication. The last operational Strutters in the RFC were replaced by
Sopwith Camels in late October 1917. The type's long range and stability were good qualities for a home defence fighter and it served with
37,
44 and
78 squadrons. Most of the Strutters supplied to home defence units had been built as two-seaters but many were converted locally to single-seaters to improve performance. Some of these single-seaters were similar to the bomber variant but others were of a different type, known (like similarly adapted Sopwith Camels) as the
Sopwith Comic. The cockpit was moved back behind the wings and one or two Lewis guns, either mounted on
Foster mountings or fixed to fire upwards, outside the arc of the propeller, replaced the synchronised Vickers. The RNAS used most of their Strutters as bombers (in the Aegean and Macedonia as well as in France) and as shipboard aircraft, where it was known as the '''Ship's Strutter''' and flew from
aircraft carriers, other warships of the
Royal Navy, and the battlecruiser . It had been planned to use them on the
Tondern raid, but Sopwith Camels were used instead. The RNAS and the RFC (and after April 1918 the
Royal Air Force [RAF]) used the type as a trainer after it had been withdrawn from operational service and like the
Sopwith Pup, it proved a popular personal aircraft for senior officers.
In French service The largest user of the Sopwith was actually the French . By May 1916 it was obvious that the
pusher Farman and
Breguet bombers and reconnaissance aircraft were obsolete and with the failure of their
tractor aircraft replacements, particularly the
Nieuport 14, the Sopwith was ordered in large numbers from French manufacturers in three versions, the SOP. 1A.2 (two-seat reconnaissance), SOP. 1B.2 (two-seat bomber) and SOP. 1B.1 (single-seat bomber). supplemented by large numbers delivered directly from Britain and France. The Strutter remained in large scale use by both the Soviet forces and
White Russians during the
Russian Civil War and
Polish-Soviet war. Three were captured during this war and used by the Poles in 1919–1920. Other captured ones were used by Baltic states. The American Expeditionary Force purchased 384 two-seat Strutter observation aircraft and 130 single-seat bombers from France in 1917–18. While mainly used for training, they were used operationally by the
90th Aero Squadron as an interim measure, due to a shortage of later types. The
U.S. Navy used a number of the two-seat Sopwiths, along with
Nieuport 28s and
Hanriot HD.1s and
2s as ships' aircraft in the early postwar years, testing the use of aircraft from platforms mounted on the turrets of battleships. The Strutter also served with the
Imperial Japanese Army Air Force – some examples serving in the Japanese expeditionary force in Siberia during 1918. Around 1,500 Strutters were built for the Royal Flying Corps and the
Royal Naval Air Service and between 4,200 and 4,500 were built in
France. ==Variants and designations==