P-3C Orion Aircraft History

                    In February 1959, the Navy awarded Lockheed a agreement to build up a replacement for the aging P2V Neptune. The P3V Orion, derived from Lockheed's successful L188 Electra airliner, entered the inventory in July 1962, and more than 30 years later it remains the Navy's sole land-based antisubmarine warfare aircraft. It has gone through one designation change (P3V 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 making line at the Lockheed plant in April 1990.