Lockheed S-3 Viking

The Lockheed S-3 Viking is a four-crew, twin-engine turbofan-powered subsonic anti-submarine jet aircraft designed and produced by the American aerospace manufacturer Lockheed Corporation. Because of its characteristic sound, it was nicknamed the "War Hoover" after the vacuum cleaner brand.

The S-3 was developed in response to the VSX program conducted by the U.S. Navy (USN) to procure a successor anti-submarine warfare (ASW) aircraft to the Grumman S-2 Tracker. It was designed, with assistance from Ling-Temco-Vought (LTV), to be a carrier-based, subsonic, all-weather, long-range, multi-mission aircraft.

On 21 January 1972, the prototype YS-3A performed the type's maiden flight. Upon entering regular service during February 1974, it proved to be a reliable workhorse. In the ASW role, the S-3 carried automated weapons and in-flight refueling gear. Further variants, such as the ES-3A Shadow carrier-based electronic intelligence (ELINT) platform, and the US-3A carrier-based utility and cargo transport, arrived during the 1980s and 1990s. In the late 1990s, the S-3B's mission focus shifted to surface warfare and aerial refueling a carrier battle group. It saw combat during the Gulf War of the early 1990s, the Yugoslav Wars of the mid-to-late 1990s, and the War in Afghanistan during the 2000s.

The S-3 was removed from front-line fleet service aboard aircraft carriers in January 2009, its missions having been taken over by the P-3C Orion, P-8 Poseidon, SH-60 Seahawk, and F/A-18E/F Super Hornet. For more than a decade after that, some S-3s 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 at the NAVAIR Point Mugu Range. These final examples in U.S. Navy service were retired in early 2016. The last operational S-3 was used by the National Aeronautics and Space Administration (NASA) at its Glenn Research Center until NASA retired it in mid-2021. Most retired S-3s were placed into storage while options for their future were investigated. During the 2010s, Lockheed Martin proposed to refurbish them for carrier onboard delivery. The Republic of Korea Navy also had plans to operate revived S-3s for ASW; these plans were cancelled in 2017.

Development

alt=|thumb|YS-3A prototype

thumb|S-3 escape system testing

In the mid-1960s, the United States Navy (USN) formulated the VSX (Heavier-than-air, Anti-submarine, Experimental) requirement, which sought a dedicated anti-submarine aircraft capable of flying off of its aircraft carriers as a replacement for its existing inventory of piston-engined Grumman S-2 Trackers. The service issued a request for proposals to industry. During August 1968, a team led by Lockheed, as well as a rival team comprising Convair and Grumman, were requested to further develop their proposals to meet this requirement.

At this stage, Lockheed recognised that it had little experience in designing carrier based aircraft, thus the company reached out to the industrial conglomerate Ling-Temco-Vought (LTV), which joined the team. LTV assumed responsibility for the design of various elements of the airframe, such as the folding wings and tail, the engine nacelles, and the landing gear, some of which had been derived from the earlier LTV A-7 Corsair II and Vought F-8 Crusader. Sperry Univac Federal Systems was assigned the task of developing the aircraft's onboard computers which integrated input from sensors and sonobuoys.

On 4 August 1969, Lockheed's design was selected as the winner of the VSX contest; an order for eight prototypes, designated YS-3A, was promptly received by the company. very slightly swept with a leading edge angle of 15° and an almost straight trailing edge. Its twin GE TF-34 high-bypass turbofan engines mounted in nacelles under the wings provide excellent fuel efficiency, providing the Viking with the required long range and endurance, while also maintaining relatively docile engine-out characteristics.

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. 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.

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.

Starting in 1987, the majority of S-3As were progressively upgraded to the improved S-3B standard; this involved the addition of several new sensors, avionics, and weapons systems, which included the capability to launch the AGM-84 Harpoon anti-ship missile.

As a consequence of the collapse of the Soviet Union and the breakup of the Warsaw Pact in the early 1990s, the Soviet-Russian submarine threat was perceived as much reduced, and the Vikings had the majority of their antisubmarine warfare equipment removed. The aircraft's mission subsequently changed to sea surface search, sea and ground attack, over-the-horizon targeting, and aircraft refueling. It was commonly deployed to hunt for Scud missile launcher. The Vikings also identified and targeted numerous Iraqi naval vessels, and even destroyed anti-aircraft gun emplacements and coastal radars.

Final years and retirement

thumb|[[VX-30's S-3B, callsign "Bloodhound 700", in 2010.]]

thumb|S-3B N601NA was operated by [[NASA from 2009 to 2021.]]

A proposed airframe known as the Common Support Aircraft was advanced as a successor to the S-3, E-2, and C-2, but this initiative failed to materialize. In 1998, the U.S. Navy awarded a $40 million contract for Lockheed Martin to perform a full-scale Fatigue testing of the existing S-3s; these tests, which commenced in June 2001, were aimed at extending the viable service life of each remaining aircraft, which had originally been certified for a structural life of 13,000 flight-hours. It was hoped that this could be extended to as much as 17,750 hours.

The final carrier-based S-3B squadron, VS-22, was decommissioned at NAS Jacksonville on 29 January 2009. Sea Control Wing Atlantic was decommissioned the following day, along with the last S-3s in frontline fleet service. These S-3Bs are flown by Air Test and Evaluation Squadron Thirty (VX-30) based out of NAS Point Mugu, California. By late 2015, the U.S. Navy were operating a total of three Vikings in support roles. One was relocated to The Boneyard in November 2015, while the final two were retired, one being stored and the other transferred to NASA, on 11 January 2016, officially retiring the S-3 from Navy service.

During 2004, NASA acquired four of the withdrawn S-3Bs for use at its Glenn Research Center. In 2009, one of these aircraft (USN BuNo 160607) was given the civil registration N601NA, it was involved in numerous tests conducted by the agency. For over a decade, this aircraft was flying almost every day in support for various research programs; However, a lack of spare parts and increasing difficulty supporting the type meant their use could not continue in the long term. The last of the NASA's S-3Bs, which were the final working members of the type in existence with any operator at that point, were retired on 13 July 2021.

Potential revival and proposals

In October 2013, the Republic of Korea Navy expressed its interest in acquiring up to 18 ex-USN S-3s to augment their fleet of 16 Lockheed P-3 Orion aircraft. In August 2015, a military program review group approved a proposal to incorporate 12 mothballed S-3s to perform ASW duties; the Viking plan was sent onto the Defense Acquisition Program Administration for further assessment before final approval decision by the national defense system committee. Although the planes are relatively old, being in storage has supposedly kept them serviceable, and using them is an affordable means of fulfilling short-range airborne ASW capabilities that were vacated by the retirement of the S-2 Tracker. Refurbished S-3s could have been returned to use by 2019.

During April 2014, Lockheed Martin announced that they would offer refurbished and remanufactured S-3s, dubbed the C-3, as a replacement for the Northrop Grumman C-2A Greyhound for carrier onboard delivery. The requirement for 35 aircraft would be met from the 91 S-3s currently in storage. In February 2015, the Navy announced that the Bell Boeing V-22 Osprey had been selected to replace the C-2 for the COD mission. A SV-22 was a proposed anti-submarine warfare variant the U.S. Navy studied in the 1980s to replace S-3 Viking and late model SH-2 Seasprite ASW helicopters.

Variants

thumb|US-3A of [[VRC-50 in 1987]]

thumb|ES-3As of VQ-5

thumb|S-3B with D-704 [[buddy store]]

thumb|ES-3A Shadow of [[VQ-6]]

;S-3A

:First production version, 187 built.

;S-3B

:Upgraded avionics, AN/APS-137 inverse synthetic aperture radar, Joint Tactical Information Distribution System, AGM-84 Harpoon launch capability, first flight 13 September 1984, 119 converted from S-3As.

;ES-3A Shadow

:Designed as a carrier-based, subsonic, all-weather, long-range, electronic reconnaissance (ELINT) aircraft. 16 aircraft were modified to replace the EA-3B Skywarrior, entering fleet service in 1993. The ES-3A carried an extensive suite of electronic sensors and communications gear, replacing the S-3's submarine detection, armament, and maritime surveillance equipment with avionics racks accommodating the ES-3A's sensors. These modifications had minor impact on airspeed, reducing its top rated speed from but had no noticeable impact on the aircraft's range and actually increased its rated loiter time. Because these aircraft were standoff indications and warnings platforms and were never intended to be part of an ingress strike package, this new speed limitation was considered insignificant.

;KS-3A

:Proposed dedicated air tanker with fuel capacity of 4,382 US gal (16,600 L), one converted from YS-3A, later converted to US-3A.

Operators

;

United States Navy (former)
VS-21 Red Tails (1975-2005)
VS-22 Checkmates (1976-2009)
VS-24 Scouts (1977-2007)
VS-27 Seawolves/Grim Watchdogs (1987-1994)
VS-28 Hukkers/Gamblers (1976-1992)
VS-29 Dragonfires (1976-2004)
VS-30 Diamond Cutters (1977-2007)
VS-31 Topcats (1977-2008)
VS-33 Screwbirds (1977-2006)
VS-35 Boomerangers/Blue Wolves (1986-88/1991-2005)
VS-37 Sawbucks (1978-1995)
VS-38 Red Griffins (1978-2004)
VS-41 Shamrocks (1974-2006)
VQ-5 Sea Shadows (1991-1999)
VQ-6 Black Ravens (1991-1999)
VX-1 Pioneers (Unknown)
NASA (former)

Aircraft on display

thumb|S-3 on display at the [[Air Zoo]]

;YS-3A

157993 – NAS Jacksonville Aircraft Heritage Park, NAS Jacksonville, Jacksonville, Florida.

;S-3A

159417 – Celebrity Row, Davis-Monthan AFB (North Side), Tucson, Arizona.

;ES-3A

159404 – Celebrity Row, Davis-Monthan AFB (North Side), Tucson, Arizona.

;S-3B

thumb|S-3B on display at the Patuxent River Naval Air Museum

159387 – Navy One National Naval Aviation Museum, NAS Pensacola, Pensacola, Florida.
159412 – NAS North Island, San Diego, California.
159731 – at the Patriot's Point Naval and Maritime Museum, Charleston, South Carolina.
159743 – Aviation History & Technology Center, Dobbins ARB (formerly Atlanta NAS), Marietta, Georgia.
159755 – NAS Pensacola, Pensacola, Florida.
159766 – at San Diego, California.
159770 – Patuxent River Naval Air Museum, Lexington Park, Maryland.
160123 – Air Zoo at Kalamazoo, Michigan.
160599 – at the former NAS Alameda, Alameda, California.
160604 – Pima Air and Space Museum (adjacent to Davis-Monthan AFB), Tucson, Arizona.
N601NA (160607) - NASA Viking San Diego Air & Space Museum, San Diego, California.

|prime units?= kts

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General characteristics

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|crew= 4 (pilot, co-pilot, TACCO, sensor operator)

|length ft= 53

|length in= 4

|length note=

|span ft= 68

|span in= 8

|span note=

|width ft= 29

|width in= 6

|width note= folded

|height ft= 22

|height in= 9

|height note=

Height tail folded:

|wing area sqft= 598

|wing area note=

|aspect ratio= 7.73

|airfoil= root: NACA 0016.3-1.03 32.7/100 mod; tip: NACA 0012-1.10 40/1.00 mod

|empty weight lb= 26,581

|empty weight note=

|gross weight lb= 38,192

|gross weight note=

|max takeoff weight lb= 52,539

|max takeoff weight note=

|fuel capacity=

Internal fuel capacity: of JP-5 fuel
External fuel capacity: 2 × drop tanks

|more general=

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Powerplant

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|eng1 number= 2

|eng1 name= General Electric TF34-GE-2

|eng1 type= turbofan engines

|eng1 lbf= 9,275

|eng1 note=

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Performance

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|max speed kts= 429

|max speed note= at sea level

|max speed mach= 0.79

|cruise speed kts= 350

|cruise speed note=

|stall speed kts= 97

|stall speed note=

|never exceed speed kts=

|never exceed speed note=

|minimum control speed kts=

|minimum control speed note=

|range nmi= 2,765

|range note=

|combat range nmi= 460.5

|combat range note=

|ferry range nmi= 3,368

|ferry range note=

|endurance=

|ceiling ft= 40,900

|ceiling note=

|g limits=

|roll rate=

|climb rate ftmin= 5,120

|climb rate note=

|time to altitude=

|wing loading lb/sqft= 68.5

|wing loading note=

|fuel consumption lb/mi=

|thrust/weight= 0.353

|more performance=

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Armament

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|armament=

Up to on 4 internal and 2 external hardpoints, including:
10 × Mark 82 bombs
2 × Mark 83 bombs
2 × Mark 84 bombs
6 × CBU-100 cluster bombs
2 × Mark 50 torpedoes
4 × Mark 46 torpedoes
6 × mines or depth charges
2 × B57 nuclear bombs (depth charges)
2 × AGM-65E/F Maverick missiles
2 × AGM-84D Harpoon missiles
1 × AGM-84H/K SLAM-ER missile
The underwing hardpoints can also be fitted with unguided rocket pods or 300 US gal (1,136 L) fuel tanks.

|avionics=

CPU-175/A Central air data computer
AN/APS-116 sea search radar, maximum range
Upgraded on S-3B to AN/APS-137 inverse synthetic aperture radar (ISAR)
OR-89 forward looking infrared (FLIR) camera with 3× zoom
AN/ARS-2 sonobuoy receiver with 13 blade antennas on the airframe for precise buoy location (sonobuoy reference system)
AN/ASQ-81 magnetic anomaly detector (MAD)
AN/ALR-47 electronic support measures (ESM) emitter-location system, with boxy receiver pods fitted to the wingtips, to locate adversary communications and radar transmitters
AN/ASN-92 inertial navigation system (INS) with Doppler radar navigation and TACAN
Up to 60 sonobuoys (59 tactical, 1 search and rescue)

Lockheed S-3 Viking

Development

Final years and retirement

Potential revival and proposals

Variants

Operators

Aircraft on display

See also

References

Citations

Bibliography

External links