In May 1916, the RNAS received its first Pups for operational trials with "A" Naval Squadron. The first Pups reached the Western Front in October 1916 with No. 8 Squadron RNAS, and proved successful, with the squadron's Pups claiming 20 enemy machines destroyed in operations over the Somme battlefield by the end of the year. The first RFC Squadron to re-equip with the Pup was No. 54 Squadron, which arrived in France in December. The Pup quickly proved its superiority over the early Fokker, Halberstadt and Albatros biplanes. After encountering the Pup in combat, Manfred von Richthofen said, "We saw at once that the enemy aeroplane was superior to ours."
The Pup's light weight and generous wing area gave it a good rate of climb. Agility was enhanced by installing ailerons on both wings. The Pup had half the horsepower and armament of the German Albatros D.III, but was much more manoeuvrable, especially over 15,000 ft (4,500 m) due to its low wing loading. Ace James McCudden stated that "When it came to manoeuvring, the Sopwith [Pup] would turn twice to an Albatros' once ... it was a remarkably fine machine for general all-round flying. It was so extremely light and well surfaced that after a little practice one could almost land it on a tennis court." However, the Pup was also longitudinally unstable.
At the peak of its operational deployment, the Pup equipped only four RNAS squadrons (Nos. 3, 4, 8 and 9), and three RFC squadrons (Nos. 54, 46 and 66). By the spring of 1917, the Pup had been outclassed by the newest German fighters. The RNAS replaced their Pups, first with Sopwith Triplanes, and then with Sopwith Camels. The RFC soldiered on with Pups, in spite of increasing casualties, until it was possible to replace them with Camels in December 1917.
Home Defence duties
The raids on London by Gotha bombers in mid-1917 caused far more damage and casualties than the earlier airship raids. The ineffective response by British interceptor units had serious political repercussions. In response, No. 66 Squadron was withdrawn to Calais for a short period, and No. 46 was transferred for several weeks to Sutton's Farm airfield near London. Two new Pup squadrons were formed specifically for Home Defence duties, No. 112 in July, and No. 61 in August.
The first Pups delivered to Home Defence units utilised the 80 hp Le Rhône, but subsequent Home Defence Pups standardised on the more powerful 100 hp Gnome Monosoupape, which provided improved rate of climb. These aircraft were distinguishable by the addition of vents in the cowling face.
Sopwith Pups were also used in many pioneering carrier experiments. On 2 August 1917, a Pup flown by Sqn Cdr Edwin Dunning became the first aircraft to land aboard a moving ship, HMS Furious. Dunning was killed on his third landing when the Pup fell over the side of the ship. The Pup began operations on the carriers in early 1917; the first aircraft were fitted with skid undercarriages in place of the standard landing gear. Landings utilised a system of deck wires to "trap" the aircraft. Later versions reverted to the normal undercarriage. Pups were used as ship-based fighters on three carriers:
HMS Campania, Furious and Manxman. A number of other Pups were deployed to cruisers and battleships where they were launched from platforms attached to gun turrets. A Pup flown from a platform on the cruiser HMS Yarmouth shot down the German Zeppelin L 23 off the Danish coast on 21 August 1917.
The U.S. Navy also employed the Sopwith Pup with famed Australian/British test pilot Edgar Percival testing the use of carrier-borne fighters. In 1926, Percival was catapulted in a Pup off the battleship USS Idaho at Guantanamo Bay, Cuba.
The Pup saw extensive use as a trainer. Student pilots completing basic flight training in the Avro 504k often graduated to the Pup as an intermediate trainer. The Pup was also used in Fighting School units for instruction in combat techniques. Many training Pups were in fact reserved by senior officers and instructors as their personal runabouts while a few survived in France as personal or squadron 'hacks' after the type was withdrawn from combat.
The Pup was officially named the Sopwith Scout. The "Pup" nickname arose because pilots considered it to be the "pup" of the larger two-seat Sopwith 1½ Strutter. The name never had official status as it was felt to be "undignified," but a precedent was set, and all later Sopwith types apart from the Triplane acquired animal names (Camel, Dolphin, Snipe etc.), which ended up with the Sopwith firm being said to have created a "flying zoo" during the First World War.