Lockheed S-3 Viking
The S-3 is a carrier-based, subsonic, all-weather, long-range, multi-mission aircraft. It operates primarily with carrier battle groups in anti-submarine warfare roles. It carries automated weapon systems and is capable of extended missions with in-flight refueling.
The Viking's primary flight controls are fully powered and are integrated with the automatic flight-control system to relieve the pilot of routine anti-submarine-warfare manoeuvring. Primary flight controls are servo-operated by dual hydraulic systems, the loss of either hydraulic system results in the loss of half the available hinge moment. Reversion to manual control is automatic if both hydraulics are lost. In normal powered operation series inputs to the elevator and rudder servos compensate for pitching moments and provide turn co-ordination and yaw damping. During autopilot operation parallel inputs to the power servos permit the pilot to, anticipate automatic manoeuvres.
The roll axis is controlled by short-span ailerons aug-mented by differential spoilers mounted on the upper and lower surfaces of each wing. The servo actuators have artificial feel built in to minimise variations in manoeuvring forces throughout the flight envelope. Ailerons and spoilers act together for rolling, with the spoilers acting alone as airbrakes when required. During emergency manual operation when there is no hydraulic power the spoilers are inhibited and the control column operates only the ailerons.
The pitch axis is controlled by a hydraulically powered elevator servo; trim is via an electrically powered actuator. The elevator servo can be operated in normal powered, series or parallel modes. In the emergency manual mode, and in the normal powered mode, the servo is controlled by the pilot. In the series mode-during manual approach with the approach power compensator on the servo is under the joint control of the pilot and the automatic flight-control system.
Rudder control allows an engine failure to be coped with at low speed or following asymmetric stores release. The rudder servo, like that for the elevator, can operate: in normal power, series, parallel or emergency manual modes. During the fin-folding sequence rudder-pedal input to the rudder servo is disconnected to enable the pilot to continue steering the aircraft on the ground using the rudder pedals.
The first S-3A Viking was rolled out at Lockheed's Burbank, California factory on November 8 1971 and was first flown on 21 January 1972. The S-3A Viking replaced the piston-engined Grumman S-2 Tracker and entered fleet service in 1974. The last production S-3A was delivered in August 1978.
Used exclusively by the US Navy (firstly VS-41 in February 1974), a total of 187 were built before production ended in 1978, these being powered by two 9,275 lb thrust General Electric TF34-GE-2 turbofan engines.
Lockheed received an initial contract in April 1986 to supply 22 production conversion kits to modify S-3As to upgraded S-3B standard. Two S-3As were modified by Lockheed in 1984/85 to serve as S-3B prototypes, the first flying on 13 September 1984. The S-3B incorporates increased acoustic processing, expanded ESM coverage, improved radar processing, a new sonobuoy reference system, and Harpoon ASM capability. The S-3B version can be fitted with buddy stores, external fuel tanks that refuel other aircraft, to act as an airborne tanker.
Sixteen S-3As were converted to ES-3A Shadows for carrier-based electronic reconnaissance (ELINT) duties.
The Lockheed US-3A Viking carrier-on-board delivery development aircraft, a version of the S-3A Viking, was flown for the first time on 2 July1976. Four US-3As are used for COD. A few units were also converted for utility and limited cargo duty, known as the US-3B, all of which were retired by 1998.
Since the submarine threat has been perceived as reduced Vikings have had their antisubmarine warfare equipment removed and are now used primarily for sea and ground attack, sea surface search, over the horizon targeting, and aircraft refueling. As a result, crews are now usually limited to two people, but three people crews are not unusual with certain missions. Navy plans called for the retirement of all Vikings by 2009.
On May 1, 2003, US President George W. Bush rode in the co-pilot seat of a Viking that landed on the aircraft carrier USS Abraham Lincoln, where he delivered his "Mission Accomplished" speech announcing the end of major combat in the 2003 invasion of Iraq. That Navy flight is the only one to use the callsign "Navy One".
Engines: 2 x General Electric TF34-GE-2 turbofan, 9275 lb (4207 kgp) thrust.
Wing span: 68 ft 8 in (20.93 m).
Length: 53 ft 4 in (16.26 m).
Height: 22 ft 9 in (6.93 m).
Wing area: 55.6 sq.m / 598.47 sq ft
Max take-off weight: 19280 kg / 42505 lb
Empty weight: 12070 kg / 26610 lb
Max. speed: 815 km/h / 506 mph
Cruise speed: 650 km/h / 404 mph
Ceiling: 11000 m / 36100 ft
Range w/max.fuel: 5700 km / 3542 miles
Engines: 2 x General Electric TF-34-GE-400B turbofan engines rated at 9,275 lb thrust each
Length: 53 feet, 4 in
Wingspan: 68 ft, 8 in
Height: 22 feet, 9 in
Empty weight: 26,650 lb
Maximum takeoff weight: 52,539 lb
Speed: 518 mph
Ceiling: 40,000 ft
Range: 2,645 mi
Armament: Up to 3,958 lb
Unit Cost: US$27 million
Lockheed S-3 Viking