The Lockheed S-3 Viking is a 4-crew, twin-engine turbofan-powered jet aircraft that was used by the U.S. Navy (USN) primarily for anti-submarine warfare. In the late 1990s, the S-3B's mission focus shifted to surface warfare and aerial refueling. The Viking also provided electronic warfare and surface surveillance capabilities to a carrier battle group. A carrier-based, subsonic, all-weather, long-range, multi-mission aircraft, it carried automated weapon systems and was capable of extended missions with in-flight refueling. Because of its characteristic sound, it was nicknamed the "War Hoover" after the vacuum cleaner brand. The S-3 was phased out from front-line fleet service aboard aircraft carriers in January 2009, with its missions taken over by aircraft like the P-3C Orion, P-8 Poseidon, Sikorsky SH-60 Seahawk, and Boeing F/A-18E/F Super Hornet. Several aircraft were flown by Air Test and Evaluation Squadron Thirty (VX-30) at Naval Base Ventura County / NAS Point Mugu, California, for range clearance and surveillance operations on the NAVAIR Point Mugu Range until 2016 and one S-3 was operated by the National Aeronautics and Space Administration (NASA) at the NASA Glenn Research Center until 2021. The S-3 is a conventional monoplane with a cantilever shoulder wing, very slightly swept with a leading edge angle of 15° and an almost straight trailing edge. Its 2 GE TF-34 high-bypass turbofan engines mounted in nacelles under the wings provide excellent fuel efficiency, giving the Viking the required long range and endurance, while maintaining docile engine-out characteristics. The aircraft can seat 4 crew members (3 officers and 1 enlisted) with pilot and copilot/tactical coordinator (COTAC) in the front of the cockpit and the tactical coordinator (TACCO) and sensor operator (SENSO) in the back. Entry is via a hatch/ladder folding down out of the lower starboard side of the fuselage behind the cockpit, in between the rear and front seats on the starboard side. When the aircraft's anti-submarine warfare (ASW) role ended in the late 1990s, the enlisted SENSOs were removed from the crew. In tanker crew configuration, the S-3B typically flew with a pilot and co-pilot/COTAC. The wing is fitted with leading edge and Fowler flaps. Spoilers are fitted to both the upper and the lower surfaces of the wings. All control surfaces are actuated by dual hydraulically boosted irreversible systems. In the event of dual hydraulic failures, an Emergency Flight Control System (EFCS) permits manual control with greatly increased stick forces and reduced control authority. For more details of development, design, operational history and variants, click here.
