The P-3C is a land-based, long range anti-submarine warfare (ASW) patrol aircraft. It has advanced submarine detection sensors such as directional frequency and ranging (DIFAR) sonobuoys and magnetic anomaly detection (MAD) equipment. The avionics system is integrated by a general purpose digital computer that supports all of the tactical displays, monitors and automatically launches ordnance and provides flight information to the pilots. In addition, the system coordinates navigation information and accepts sensor data inputs for tactical display and storage. The P-3C can either operate alone or supporting many different customers including the carrier battlegroup and amphibious readiness group. The aircraft can carry a variety of weapons internally and on wing pylons, such as the Harpoon anti-surfacemissile, the MK-50 torpedo and the MK-60 mine.

Each Maritime Patrol Aviation (MPA) squadron has nine aircraft and is manned by approximately 60 officers and 250 enlisted personnel. Each 11-person crew includes both officer and enlisted personnel. The MPA squadrons deploys to sites outside the United States for approximately six months, and generally spends one year training at home between deployments.

In February 1959, the Navy awarded Lockheed a contract to develop a replacement for the aging P-2 Neptune. The P-3V Orion entered the inventory in July 1962, and over 30 years later it remains the Navy's sole land-based antisubmarine warfare aircraft. It has gone through one designation change (P-3V to P-3) and three major models: P-3A, P-3B, and P-3C, the latter being the only one now in active service. The last Navy P-3 came off the production line at the Lockheed plant in April 1990.

Since its introduction in 1969, the P-3C has undergone a series of configuration changes to implement improvements in various mission and aircraft systems through updates to the aircraft. These changes have usually been implemented in blocks referred to as "Updates." Update I, introduced in 1975, incorporated new data processing avionics and software, while Update II in 1977 featured an infrared detection system, a sonobuoy reference system, the Harpoon antiship missile and a 28-channel magnetic tape recorder/reproducer.

Technical Evaluation (TECHEVAL) for P-3C Update III Aircraft began in March 1981, and was completed in second quarter 1982. Force Warfare Test Directorate, Naval Air Warfare Center Aircraft Division (NAVAIRWARCENACDIV), at Patuxent River, Maryland, conducted the TECHEVAL. Air Test and Evaluation Squadron One (VX-1) began Operational Test and Evaluation (OT&E) of the P-3C Update III Aircraft at NAVAIRWARCENACDIV Patuxent River in September 1981, and completed this phase of testing in January 1982. Provisional approval for service use was granted in July 1982. Approval for full production was received in January 1986 following Follow-on Operational Test and Evaluation (FOT&E). The Update III Program was enhanced by a Channel Expansion (CHEX) Program. CHEX doubled the number of sonobuoy channels that can be processed and has been installed in all P-3C Update III Aircraft. The CHEX Program began in 1983 and the tested aircraft was delivered in April 1986. CHEX TECHEVAL was accomplished from March through June 1988.

The P-3C Update III Aircraft is manned by an 11-man crew composed of five officers and six enlisted. Enlisted crewmembers are selected from the following aviation ratings: Aviation Machinist's Mate (AD), Aviation Electrician's Mate (AE), Master Chief Aircraft Maintenanceman (AF), Senior Chief Aviation Structural Mechanic (AM), Aviation Structural Mechanic (Safety Equipment) (AME), Aviation Structural Mechanic (Hydraulics) (AMH), Aviation Structural Mechanic (Structures) (AMS), Aviation Electronics Technician (AT), and Aviation Warfare Systems Operator (AW). The operational concept for the P-3C Update III and P-3C Update III AIP Aircraft remains the same as previous updates to the P-3C Aircraft, to provide tactical surveillance, reconnaissance, strike support, fleet support and warning, and monitoring of electromagnetic signals of interest for intelligence analysis. Patrol squadrons operate with nine aircraft from established Naval Air Stations (NASs) world wide. The P-3C Update III and P-3C Update III AIP Aircraft continue the P-3C's capability of operating one or more aircraft from remote airfields with no organizational or intermediate support for short periods of time.