Editing Lockheed S-3 Viking (section)

==Design==
The Lockheed S-3 Viking is a conventional [[monoplane]] with a [[cantilever wing|cantilever]] [[shoulder wing]],<ref>Taylor, John W. R.: ''Jane's All The World's Aircraft, 1977–78''. Jane's Yearbooks, London 1977, p. 329.</ref> very slightly swept with a leading edge angle of 15° and an almost straight trailing edge. Its twin [[General Electric TF34/CF34|GE TF-34]] high-bypass [[turbofan]] engines mounted in [[nacelle]]s under the wings provide excellent fuel efficiency, providing the Viking with the required long range and endurance,<ref name="WAPJ34p54-5">Elward 1998, pp. 54–55.</ref> while also maintaining relatively docile engine-out characteristics.<ref name="WAPJ34p69">Elward 1998, p. 69.</ref>

[[File:S-3A MAD DN-SC-87-05743.JPEG|thumb|S-3A with extended MAD-sensor]]
The aircraft can seat four crew members (three officers and one 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.<ref name = "desertwarrior 2009"/> 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.<ref name="WAPJ34p54-5"/> 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.<ref name=":0">{{cite book |author1 = Petrescu, Dr. Relly Victoria |author2 = Petrescu, Dr. Florian Ion |title = Lockheed Martin |date = 23 December 2012 |publisher=Books on Demand GmbH |location = Norderstedt, Germany |isbn = 978-1481826884 |page = 101}}</ref>{{self-published inline|certain=y|date=May 2023}} The wing is fitted with leading edge and [[Flap (aircraft)|Fowler flaps]]. [[Spoiler (aeronautics)|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.<ref name="JAWA76p315-6">Taylor 1976, pp. 315–316.</ref>

Unlike many tactical jets which required ground service equipment, the S-3 was equipped with an [[auxiliary power unit]] (APU) and capable of unassisted starts. The aircraft's original APU could provide only minimal electric power and pressurized air for both aircraft cooling and for the engines' pneumatic starters. A newer, more powerful APU could provide full electrical service to the aircraft. The APU itself was started from a hydraulic accumulator by pulling a handle in the cockpit. The APU accumulator was fed from the primary hydraulic system, but could also be pumped up manually (with much effort) from the cockpit.<ref name=":0" />{{self-published inline|certain=y|date=May 2023}}

All crew members sit on forward-facing, upward-firing Douglas Escapac [[zero-zero ejection seat]]s. In "group eject" mode, initiating ejection from either of the front seats ejects the entire crew in sequence, with the back seats ejecting 0.5 seconds before the front in order to provide safe separation (this was to prevent the pilots, who were more aware of what was happening outside the aircraft from ejecting without the rest of the crew, or being forced to delay ejection to order the crew to eject in an emergency; ejection from either rear seat would not eject the pilots, who had to initiate their own ejections, to prevent loss of the aircraft if a rear crewmember ejected prematurely. If a pilot ejected prematurely, the plane was lost anyway, and automatic ejection prevented the crew from crashing with a pilot-less aircraft before they were aware of what had happened). The rear seats are capable of self ejection and the ejection sequence includes a pyrotechnic charge that stows the rear keyboard trays out of the occupants' way immediately before ejection. Safe ejection requires the seats to be weighted in pairs, and when flying with a single crewman in the back the unoccupied seat is fitted with ballast.<ref name=":0" />{{self-published inline|certain=y|date=May 2023}}

At the time it entered the fleet, the S-3 introduced an unprecedented level of systems integration. Previous ASW aircraft like the [[Lockheed P-3 Orion]] and S-3's predecessor, the [[Grumman S-2 Tracker]], featured separate instrumentation and controls for each sensor system. Sensor operators often monitored paper traces, using mechanical calipers to make precise measurements and annotating data by writing on the scrolling paper. Beginning with the S-3, all sensor systems were integrated through a single General Purpose Digital Computer (GPDC). Each crew station had its own display, the co-pilot/COTAC, TACCO and SENSO displays were Multi-Purpose Displays (MPD) capable of displaying data from any of a number of systems. This new level of integration allowed the crew to consult with each other by examining the same data at multiple stations simultaneously, to manage workload by assigning responsibility for a given sensor from one station to another and to easily combine clues from each sensor to classify faint targets. As a consequence of this integration, the four-crew S-3 was considered roughly equivalent in terms of capability to the much larger P-3, operated by a crew of 12.{{Citation needed|date=May 2022}}

The aircraft has two underwing hardpoints that can be used to carry fuel tanks, general purpose and cluster bombs, missiles, rockets, and storage pods.<ref name = "desertwarrior 2009"/> It also has four internal bomb bay stations that can be used to carry general-purpose bombs, [[aerial torpedo]]es, and special stores (B57 and B61 nuclear weapons). Fifty-nine [[sonobuoy]]s are carried, as well as a dedicated Search and Rescue (SAR) chute. The S-3 is fitted with the ALE-39 countermeasure system and can carry up to 90 rounds of [[Chaff (radar countermeasure)|chaff]], [[flare]]s, and expendable jammers (or a combination of all) in three dispensers. A retractable [[magnetic anomaly detector]] (MAD) Boom is fitted in the tail.<ref name = "desertwarrior 2009"/>

In the late 1990s, the S-3B's role was changed from anti-submarine warfare (ASW) to anti-surface warfare (ASuW). As a consequence of this role change, the MAD Boom was removed, along with several hundred pounds of submarine detection electronics. As there was no remaining sonobuoy processing capability, most of the sonobuoy chutes were faired over with a blanking plate.{{Citation needed|date=May 2022}}