The Lockheed P-2 Neptune (originally designated P2V until September 1962) was a Maritime patrol and ASW

Anti-submarine warfare

Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....

 aircraft. It was developed for the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 by Lockheed

Lockheed Corporation

The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...

 to replace the Lockheed PV-1 Ventura and PV-2 Harpoon

Lockheed Ventura

The Lockheed Ventura was a bomber and patrol aircraft of World War II, used by United States and British Commonwealth forces in several guises...

, and being replaced in turn with the Lockheed P-3 Orion. Designed as a land-based aircraft, the Neptune never made a carrier landing, although a small number of aircraft were converted and deployed as carrier launched stop-gap nuclear bombers which would have to ditch or recover at land bases.