Dec 21

The God of the Sea’s Namesake

Monday, December 21, 2015 12:01 PM

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The Lockheed Neptune was the first U.S. aircraft designed from the outset for the land-based maritime patrol role, and it was the first U.S. Navy aircraft that could carry a nuclear weapon. All previous U.S. land-based maritime patrol aircraft were adapted from bomber or transport designs. Among them were Lockheed’s highly successful PBO-1 Hudson and PV-series Harpoon and Ventura aircraft. Those planes— flown by Navy and Marine Corps pilots—made major contributions to Allied victory in the Atlantic and Pacific during World War II. The Neptune was a natural progression from the twin-engine PV series.

The P-2E Neptune would later see service with the Argentine navy.

The P-2E Neptune would later see service with the Argentine navy.

In February 1943, the Navy issued Lockheed a letter of intent for the aircraft, and in April 1944, it awarded the company a contract for two XP2V-1 prototypes plus 15 production aircraft. A conventional, straight-wing plane with
a distinctive tall tail fin, the Neptune was powered by twin radial engines. Most Neptune variants were fitted with 400-gallon wingtip tanks. The initial P2V design provided for nose, dorsal, and tail turrets with twin .50-caliber machine guns. But some early P2V-1s had six 20-mm cannon in a solid nose structure plus twin .50-caliber or 20-mm guns in a tail turret. Later aircraft had various combinations of dorsal and tail turrets, most with a clear plastic nose.

Variants had the tail turret replaced by a magnetic anomaly detector (MAD) antenna. Like its predecessors, the Neptune had an internal weapons bay that could accommodate antisubmarine torpedoes, depth charges, and mines. In later aircraft, rockets could be carried on eight wing pylons. Maximum weapons payload—internal and external—was 12,000 pounds.

The first of the two XP2V-1 prototypes flew on 17 May 1945. The aircraft was an immediate success. On 29 September 1946, with Commander Thomas D. Davies at the controls,
the first production P2V-1—named Truculent Turtle—took off from Perth, Australia, to fly 11,235.6 nautical miles, landing in Columbus, Ohio, after a flight of 55 hours, 17 minutes. The aircraft was overloaded with an estimated 8,592 gallons of fuel and carried a crew of three and a kangaroo, the latter to jokingly prove the plane had taken off from Australia. Aided
by four JATO rockets, the aircraft, at 85,575 pounds, was the heaviest twin-engine plane to take off up to that time. Davies had planned to land at Naval Air Station Anacostia in Washington, D.C., but bad weather caused the flight to end at Columbus. Still, it established an unrefueled distance record that stood until 16 years later when bettered by an Air Force B-52H Stratofortress. (Neptunes were not configured for in-flight refueling.)

The first P2V-1 entered the fleet in March 1947.

The Neptune’s outstanding design
led to the decision to modify one P2V-2 and 11 P2V-3 aircraft to the P2V-3C configuration for carrier takeoff— carrying a nuclear weapon. That was a limited, interim nuclear-strike capability until aircraft designed to carry a nuclear weapon from carriers became available. The Neptunes were to be flown to overseas bases and lifted by crane aboard Midway-class carriers, loaded with Mark 8 atomic bombs, and launched against targets in the Soviet Union. In preparation for such operations, after scores of practice takeoffs from airfields ashore, on 28 April 1948, two P2V-2 Neptunes, with JATO assistance, took off from the carrier Coral Sea (CVB-
43) off the Virginia coast. More carrier launches followed, establishing the feasibility of such ad hoc operations. Although Neptune landings aboard Midway CVBs were proposed, and practiced ashore, no such trials were undertaken.

There was a steady progression of improvements to the Neptunes. The ultimate variant to enter service was the P2V-7, which was additionally fitted with two Westinghouse J34- WE-34/36 turbojet engines mounted in pods for “burst speed” when closing with submarine contacts as well as for increased takeoff power. In addition to the standard antisubmarine sensors of surface-search radar and droppable sonobuoys, the P2V-7 introduced the AN/ASQ-8 MAD antenna fitted in a large tailcone “stinger.” MAD as well as the jet pods subsequently were fitted to earlier P2V-5 and P2V-6 aircraft. (The 1962 redesignation of U.S. military aircraft saw the P2V changed to P-2.) Some variants were optimized for aerial minelaying, and the P2V-6M (later MP-2F) was fitted to carry the Petrel air-to-surface missile. The P2V-3W and later aircraft had the large AN/APS-20 search radar intended primarily for detecting submarine snorkels—air intake devices. The P2V-3Z was an armored VIP transport. The small number of P2V- 7LP (LP-2J) aircraft were fitted with skis and other equipment for Arctic photo reconnaissance and mapping.

Several Neptunes carrying additional electronic intercept equipment flew
spy missions along the coasts of Siberia, North Korea, and China. Some of those flights were made under the aegis of the Central Intelligence Agency by seven P2V-7U aircraft—designated rB-69A— and flown by Taiwanese crews. These spy flights became tempting targets for Soviet and Chinese fighter aircraft. The Soviets shot down three Neptunes flying over international waters, while another fell to Chinese antiaircraft fire. Other planes were damaged by Chinese and Soviet fighters, with Neptune gunners fighting off some attackers.

Several Neptunes were extensively modified for special attack operations in the Vietnam War, the naval aircraft being designated OP-2E with the Army flying the AP-2H variant. But most of the Neptunes spent their careers flying over endless miles of ocean, searching out surface ships of interest and seeking enemy submarines. Those roles became especially important during the Cuban Missile Crisis in the fall of 1962, when Neptunes and the new P-3A Orion patrol aircraft monitored merchant ships traveling to and from Cuba. And they searched out the Soviet submarines that were detected in the western Atlantic during the crisis.

In August 1963, this Lockheed SP-2H Neptune of Patrol Squadron 56 Dragons was deployed to South America for Exercise Unitas IV.

In August 1963, this Lockheed SP-2H Neptune of Patrol Squadron 56 Dragons was deployed to South America for Exercise Unitas IV.

The Neptune remained in active Navy patrol squadrons until 1970; the last flight by an active antisubmarine Neptune, in February 1970, was piloted by rear Admiral Tom Davies. They continued in service with the Naval Air reserve up to 1979, with specialized EP-2H electronic and DP-2H Firebee drone variants being flown until 1980.

A total of 1,099 P2Vs were produced by Lockheed from 1945 through 1962; 89 additional aircraft were produced in Japan by Kawasaki through 1979 (designated P-2J). This effort marks one of the longest aircraft production runs in history.

Lockheed proposed a lighter variant of the Neptune, designated P2V-8, but it was not pursued because of the advent of the firm’s very capable P-3 Orion.

Ten other nations flew Neptunes: Argentina, Australia, Brazil, Canada, Chile, France, Great Britain, Japan, the Netherlands, and Portugal. The 25 P2V-7 aircraft flown by Canada could carry U.S. B57 nuclear depth bombs, as could the 12 P2V-5 aircraft flown by the Netherlands; the latter aircraft were replaced by 15 improved P2V-7/ SP-2H aircraft in 1962. The 52 P2V-5 Neptunes provided to the royal Air Force for maritime patrol did not have a nuclear capability.

Japan was the last nation to operate Neptunes, those being flown by the Maritime Self-Defense Force until 1994. Thus ended the career of a remarkable and effective—and historic—aircraft.

 

SOURCES:

A detailed history of the design and development of the Neptune is found in René J. Francillon, Lockheed Aircraft since 1913 (Annapolis, MD: Naval Institute Press, 1987), pp. 261–80.

See N. Polmar, “The First Nuclear Bomber,” Naval History (February 2003), p. 14.

See N. Polmar and Peter B. Mersky, “Neptunes Over the Jungle,” Naval History (December 1998), p. 68.