HMS "Pegasus" was fitted with a flying-off deck forward, intended for aircraft with wheeled undercarriages, and a prominent hangar aft. Two electric cranes were fitted aft and a twin-boom derrick forward to handle her aircraft. The smaller forward hangar was built under the ship's bridge and the aircraft were raised to the flight deck overhead by one of the first lifts in the Royal Navy. The forward hangar could fit five single-seat fighters and the rear hangar had a capacity of four floatplanes. The ship could lower them into the water while steaming at and recover the floatplanes at . When "Pegasus" commissioned in 1917 she was assigned four Short Type 184 torpedo bombers and four Beardmore W.B.III fighters. In late 1918 she carried four Sopwith Camel 2F.1, one Type 184 and three Fairey Campania reconnaissance aircraft. In 1919 she began to operate various models of the Fairey III.