lockheed p2v-1 neptune

Even before the United States’ entry into World War Two, it had become apparent that the US Navy would need a land-based patrol bomber with greater performance than the Lockheed Hudson, a light bomber and coastal reconnaissance aircraft, and the Ventura a the follow up to the Hudson, which was larger, heavier, with more powerful engines. Both aircraft designs were based on earlier Lockheed passenger transports. What the Navy needed was an aircraft designed specifically for the primary mission of day and night ASW and anti-shipping operations. Although no official requirement was issued, preliminary work on V-135 was begun in September 1941 by chief engineer John B. Wassall and his Vega team.

 
The initial V-135 design concept called for an aircraft with a gross weight of 25,000 to 35,000 lb., having power operated turrets, tricycle landing gear and the ability to carry two torpedoes, bombs and depth charges internally. The preferred powerplants were a pair of Wright R-3550s producing 2000 hp. Mac V. F. Short, Vice President Engineering of the Vega Airplane Company authorized the first internal work order for design studies of a new aircraft on December 6, 1941, the day before the Japanese attack on Pearl Harbor.

Progress on the new patrol plane was slow as the Navy needed proven aircraft during the months following the Japanese attack on Pearl Harbor. By early 1943 the Navy switched its procurement attention from acquiring immediately available aircraft, to supporting the development of newer and more capable types. The Navy issued a letter of intent on February 19, 1943, to the Vega Airplane Corporation for two XP2V-1 prototypes based on the V-146 design study. The V-146 was itself a development of the V-135 with a revised tail, a lowered wing and a relocated dorsal turret. Contact NOa(s)-375 was awarded on April 4, 1944 for the construction of the two prototypes, and ten days later, Contact NOa(s)-3297 for fifteen production P2V-1s. 

During this time, the PV-2 Harpoon still had a higher priority than the XP2V-1 in both engineering staff and floor space allocation. It was not until the summer of 1944 that project engineer R. A. Baily was able to get the project into high gear. 

Through the use of new designs and improved production techniques, Lockheed was able to meet the design’s need for long range, short takeoff and easy maintenance. This design philosophy would a provide easier production and decrease the manufacturing cost of each individual aircraft.

One design feature was the major portion of the fuselage contour was curved in only one direction permitting the use of uniformed metal skins. Expensive forming was eliminated by producing the center wing and mid fuselage sections, including the bomb bay door area, as a continuous cross section. This allowed multiple use of numerous parts and assemblies. The wing and fuselage intersection was unfilleted, the wing box running continuously through the fuselage. This also allowed the entire bomb bay load to be directly distributed throughout the wings.

The Neptune was designed to be manufactured into easily accessible sub-assemblies, keeping mating and final assembly time to a minimum. With all these design considerations, the Neptune became much more serviceable. A complete engine change could be accomplished in 30 minutes, a propeller in 22 minutes and an outer wing panel in 79 minutes. The attention to production and tooling details ensured that Lockheed would set economic standards that would set a precedent in the aerospace industry.

In the spring of 1945, thirteen months after the initial contract was awarded, the XP2V-1 Neptune prototype was ready to fly.

 The XP2V-1 (43237) was first flown on 17 May 1945 at Burbank, CA, three months before the end of WWII. The second prototype After extensive testing of both prototypes during the summer and fall of 1945 the XP2V-1 was delivered to the Navy in July of 1946. the Neptune prototype was a good performer, Handling characteristics were smooth — with directional stability, maneuverability, and good single-engine control. The only major change dictated by the trial program was the elimination of the prototypes' dorsal fin on subsequent production aircraft.

At the time of the XP2V-1s maiden flight, Lockheed had received contracts for two prototypes and 116 production aircraft. However, following the end of the war, orders were reduced from by 100 aircraft to two XP2V-1s. fourteen production P2V-1s.

Fifteen P2V-1 Neptunes were built for the US Navy the first of which reached Fleet service with VPML-2 at NAS Miramar on 13 March 1947.   All fifteen P2V-1s had been delivered to the US Navy by the end of May 1947.  VPML-2 was was redesignated Patrol Squadron TWO (VP-2) on 1 September 1948, the second squadron to be assigned the VP-2 designation.  By November 1948, the squadron's P2V-1 were replaced by the P2V-3/3W. 

Looking to set a new world record, the third production P2V-1 (89082) was modified to carry an enormous amount of fuel. By removing all armament and combat equipment and the addition of a new streamlined nose, the "Turtle's" empty weight was reduced to 29,240lbs. With additional fuel tanks including wing tip tanks, and fuel, the "Turtle" grossed out at 85,240lbs. Piloted by Commander Thomas D Davies with a full air crew aboard, "The Truculent Turtle" flew a record setting unrefueled non-stop flight from Perth, Australia to Columbus, OH, short of its intended destination of Washington, DC.  A new absolute world record of 11,235-6 miles (18,081-98 km) in 55 hr 17 min had been established.   When the aircraft was taken out of service years later, it was placed on display at NAS Norfolk, Va. This historic aircraft is now on display at the National Museum of Naval Aviation, Pensacola, Fla.

Much has been written over the years recounting the Turtles famous flight.  Award-winning author Jim Leeke has crafted a well-researched and expertly written history of the Turtle's record-breaking flight.  Order a copy from your favorite bookseller!

The Turtle and the Dreamboat: The Cold War Flights That Forever Changed the Course of Global Aviation

By Jim Leeke. 

University of Nebraska Press, 2022

The fifth P2V-1 airframe (BuNo 89086) was modified during construction to serve as prototype for the P2V-2 version.  Powered by 2,800 hp Wright R-3350-24Ws with water injection, it was first flown on 7 January 1947.