US Navy designation: S-3
TYPE: Carrier-borne ASW aircraft.
PROGRAMME: Production of 187 S-3As for US Navy ended mid-1978, tooling then stored at Burbank pending further orders; US-3A (COD) and KS-3A (dedicated tanker) demonstrators evaluated by US Navy early 1980; three earlier S-3As modified to US-3A 1982; KS-3A also converted to US-3A late 1983; S-3A fitted with Sargent-Fletcher buddy pack under port wing (to transfer fuel from internal tanks) and external tank under starboard wing; tested 1984 and adopted (ASW capability not affected).
VARIANTS: S-3A: Initial production ASW version.
S-3B: Lockheed defined Weapon System Improvement Program under US Navy contract 1980; full-scale development ordered 18 August 1981 and designated S-3B; first flight of first of two development S-3Bs 13 September 1984; flight testing completed August 1985 and six months' operational evaluation 1986; 22 kits plus spares and support ordered 28 April 1986 for installation at Cecil Field NAS, Florida; two prototype S-3B kits delivered 1987; 24 more kits ordered December 1988 for delivery by August 1992; first S-3B delivery to VS-27 17 December 1987; 42 S-3Bs completed for Atlantic Fleet by January 1990; VS-27, 30 and 32 re-equipped at Cecil Field, Florida, plus VS-28 and 31 in prospect; Lockheed has proposed kits for Pacific Fleet.
ES-3A: Contract for development of electronic reconnaissance E-3A awarded March 1988; S-3A for conversion (159401) delivered to Lockheed March 1988, scheduled to fly in Summer 1990 and be re-delivered May 1991; second YS-3A (157993) with 60 aerials and domes completed aerodynamic testing January 1990; original ES-3A development contract allowed for 15 production systems; nine modification kits ordered early 1989 for delivery by August 1991; airframe modification at Burbank and kit installation at LASG Aeromod Center at Greenville, South Carolina; two new squadrons, VQ-5 and VQ-6. formed at Agana NAS, Guam, 15 April 1991 and Cecil Field, Florida, August 1991; ES-3A will supplement, but not replace, EA-3B Skywarrior in US Navy Battle Group Passive Horizon Extension System for long-range signals monitoring.
Weapons bay used for avionics as well as rear fuselage; starboard dual controls replaced by displays and controls for electronic warfare co-ordinating officer. Operational system, simplified from that of EP-3E Orion, includes AN/ALR-76 ESM, possibly AN/ALR-52 frequency measuring radar and AN/ALR-60 communications analysis system; other avionics include three AN/AYK-14 computers replacing one AN/AYK-10, MIL-STD-1553 databus, Navstar GPS and Omega navigation, Link 11 data link, AN/APX-76 IFF interrogator, AN/APS-137 radar, OR-236 FLIR and avionics cooling system; suppliers include Sanders Associates (cockpit display screens), Lockheed Missiles & Space (wiring and electronics racks).
COSTS: $66 million for prototype development of electronic reconnaissance installation awarded March 1988; $56.2 million for nine modification kits ordered early 1989.
AVIONICS (S-3B): AN/AYS-1 Proteus acoustic signal processor; modified Sanders AN/OL-320/AYS data processing memory group integrated with IBM AN/UYS-1; updated Honeywell AN/AYK-10A(V) air data computer, interfaced with Harpoon anti-ship missile and other new systems; improved electronic support measures (ESM); Hazeltine AN/ARR-78 sonobuoy receiver system; Precision Echo AN/AQH-7 analog tape recorder, Cubic AN/ARS-4 sonobuoy reference system; Texas Instruments AN/APS-137(V)1 radar, incorporating inverse synthetic aperture radar (ISAR) techniques; modified Goodyear AN/ALE-39 chaff/flare dispensing system; IBM AN/ALR-76 ESM, and provision for future advanced navigation and communications systems including GPS and JTIDS.
ARMAMENT: S-3A/B weapon options include four Mk 46/50 torpedoes, two B57 nuclear depth charges, four Mk 82 560 lb bombs or four Mk 36 destructors all stowed internally; plus underwing armament of six Mk 82/86s, two Mk 52/55/56 mines, two Mk 60 torpedoes, two AGM-84 Harpoon anti-ship missiles, or six LAU-10C/-68A/-69A rocket pods/SUU-44A flare pods.