rocket projectiles; other equipment included 100 gallon external fuel tanks. The primary search apparatus was the Air-to-Surface Vessel (ASV) radar, which made use of a retractable radome positioned underneath the rear fuselage just to the aft of the bomb bay. The Armstrong Siddeley Double Mamba engine consisted of two Mamba engines that were mounted in a side-by-side arrangement and coupled through a common gearbox to coaxial contra-rotating propellers. Each engine drove its own propeller, and power was transmitted by a torsion shaft which was engaged through a series of sun, planet, epicyclic and spur gears to give a suitable reduction ratio and correct propeller-shaft rotation. The ASMD.1 engine (2,950 hp/2,200 kW) was used in the Gannet AS.1; ASMD.3 (3,145 hp/2,345 kW) in the AS.4; and ASMD.4 (3,875 hp/2,889 kW) in the AEW.3 variant. The Double Mamba engine could be run with one Mamba stopped and its propeller feathered, to conserve fuel and extend endurance when cruising; stopping one engine on a conventional twin-engined plane would normally create thrust asymmetry, whereas the centerline-mounted propeller arrangement avoided this. The Mamba exhausts were situated on each side of the fuselage, at the root of the wing trailing edge. The gas-turbine engine could run on kerosene, "wide-cut" turbine fuel or diesel fuel, allowing the Admiralty to eliminate the dangerous high-octane petroleum spirit required to operate piston-engined aircraft from carriers. In FAA service, the Gannet generally wore the standard camouflage scheme of a Sky (duck-egg blue) underside and fuselage sides, with Extra Dark Sea Grey upper surfaces, the fuselage demarcation line running from the nose behind the propeller spinner in a straight line to then curve and join the line of the fin. Code numbers were typically painted on the side of the fuselage ahead of the wing; roundel and serial markings were behind the wing. The T.2 and T.5 trainers were finished in silver overall, with a yellow "Trainer band" on rear fuselage and wings. Operational history During April 1954, initial deliveries of the Gannet AS.1, the initial variant, formally commenced. On 17 January 1955, the 826 NAS became the RN's first operational Gannet squadron, which promptly embarked on the newly modernised aircraft carrier . During its initial at-sea deployment in the Mediterranean, no serious issues were encountered with the Gannet aside from the standard teething issues. Later that same year, the Royal Australian Navy (RAN) stood up their first two Gannet squadrons. The