Staff Writer (Updated: 10/7/2015):
The P2V Neptune was a twin engine high-wing monoplane design. Sporting various Wright-brand powerplants throughout its production run, the aircraft featured outstanding range. A most identifiable feature being the single large rudder on the empennage, though the overall gangly design of the nose was another memorable feature. The Neptune split time between the United States Navy and the United States Air Force, though it is widely remembered for its service with the Navy branch.
The Neptune got its start as early as 1944, where two XP2V-1 prototypes are delivered with 15 production P2V-1 models. Initial models featured an impressive armament of cannons and heavy caliber machine guns of which 6 x 20mm cannons were mounted in a battery in the nose while 2 x 20mm cannon sat in a tail turret. 2 x 12.7mm machine guns are also part of the early arsenal though many of these weapons were later removed as needs for the platform changed. Internally, the Neptune was geared for military success with specialized equipment and anti-surface vessel weaponry. Chief among these weapons were the ability to carry torpedoes, mines, bombs of various weights and even externally-held high-explosive rockets (underwing).
Aircraft personnel amounted to ten in most versions. The P2V-2 was the first to do away with the nose turret armament, and instead, extended the nose assembly. The P2V-2S was an anti-submarine specialized variant while the P2V-2-2N was a cold weather derivative that was fielded with skis. The P2V-3 series brought about an early warning variant while the P2V-4 saw new and improved turbo-compound engines installed along with wingtip tanks and an APS-20 radar as standard. The P2V-5 was the first model offered up for export while the P2V-6 saw a revision to the series' defensive armament. The P2V-7 proved to be the ultimate incarnation for the P2V series featuring the MAD boom installation in place of the rear tail turret. This variant proved to be the final production variant and saw many -5's and -6's brought up to this standard. Designation of the system was then changed to SP-2H after 1962.
The United States Air Force maintained the Neptune as the RB-69A while other designations existed for specialized Southeast Asia-operating systems. The Neptune was also license-produced in Japan. Over 75% of all produced Neptunes went into service with the United States Navy and would later be replaced by another Lockheed product - the P-3 - throughout the 1970's. relegating the P2V series to supporting roles until complete withdrawal from active service.
One of the more well known Neptune aircraft remains the P2V-1 Neptune known as the "Truculent Turtle" which set a world's distance record in 1946 by flying non-stop from Australia to Ohio (Columbus). The distance for this specially-modified aircraft covered some 11,236 miles.