Lockheed P-2V Neptune

The Lockheed P-2 Neptune (designated P2V by the United States Navy prior to September 1962) was a Maritime patrol and anti-submarine warfare (ASW) aircraft. It was developed for the US Navy by Lockheed to replace the Lockheed PV-1 Ventura and PV-2 Harpoon, 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. The type was successful in export and saw service with several armed forces.

Lockheed P-2V Neptune
Class Aircraft
Type Utility
Manufacturer Lockheed Martin
Origin United States of America
Country Name Origin Year
United States of America 1945
Country Name Operational Year Retirement Year
Argentina View
Australia View
Brazil View
Canada View
China View
France View
Japan View
Netherlands View
Portugal View
United Kingdom - UK (Great Britain) View
United States of America 1947 View
ManufacturerName Production From Production To Quantity
Lockheed Martin 1162 View

Development of a new land-based patrol bomber began early in World War II, with design work starting at Lockheed's Vega subsidiary as a private venture on 6 December 1941. At first, the new design was considered a low priority compared to other aircraft in development at the time, with Vega also developing and producing the PV-2 Harpoon patrol bomber. On 19 February 1943, the U.S. Navy signed a letter of intent for two prototpe XP2Vs, which was confirmed by a formal contract on 4 April 1944 with a further 15 aircraft being ordered 10 days later. It was not until 1944 that the program went into full swing. A major factor in the design was ease of manufacture and maintenance, and this may have been a major factor in the type's long life and worldwide success. The first aircraft flew in May 1945. Production began in 1946, and the aircraft was accepted into service in 1947.

Beginning with the P2V-5F model, the Neptune became one of the first aircraft in operational service to be fitted with both piston and jet engines. The Convair B-36, several Boeing C-97 Stratofreighter, Fairchild C-123 Provider, and Avro Shackleton aircraft were also so equipped. To save the weight and complexity of two separate fuel systems, the jet engines on the P2Vs did not burn jet fuel- they burned the same fuel as the piston engines: 115–145 Avgas. The jet pods were fitted with intake doors that were kept closed when the J-34s were not running to prevent them from windmilling, allowing for economical piston-engine-only long-endurance search and patrol operations. In normal U.S. Navy operations, the jet engines were run at full power (97%) to expedite and assure all takeoffs, then shut down when the aircraft reached a safe altitude. Also, the jets were started and kept running at flight idle during low-altitude (500 feet during the day and 1,000 feet at night) anti-submarine and/or anti-shipping operations at sea as a safety measure in case one of the radials developed problems.

Normal crew access was via a ladder on the aft bulkhead of the nosewheel well to a hatch on the left side of the wheel well, then forward to the observer nose or up through another hatch to the main deck. There was also a hatch in the floor of the aft fuselage, near the sonobuoy chutes.

Variants

Lockheed produced seven main variants of the P2V. In addition, Kawasaki built the turboprop-powered P-2J in Japan.

  • XP2V-1
  • XP2V-2
  • P2V-2
  • P2V-2N "Polar Bear"  
  • P2V-2S
  • P2V-3
  • P2V-3B
  • P2V-3C
  • P2V-3W
  • P2V-3Z
  • P2V-4
  • P2V-5 
  • P2V-5F
  • P2V-5FD
  • P2V-5FE
  • P2V-5FS
  • AP-2E   
  • NP-2E
  • OP-2E
  • P2V-6
  • P2V-6B
  • P2V-6F
  • P2V-6T
  • P2V-7
  • P2V-7B   
  • P2V-7LP
  • P2V-7S
  • P2V-7U
  • AP-2H
  • AP-2H of Heavy Attack Squadron VAH-21    
  • DP-2H
  • EP-2H
  • NP-2H
  • RB-69A
  • Neptune MR.1
  • CP-122 Neptune
  • Kawasaki P-2J (P2V-Kai)



Early Cold War

Prior to the introduction of the P-3 Orion in the mid-1960s, the Neptune was the primary U.S. land-based anti-submarine patrol aircraft, intended to be operated as the hunter of a '"Hunter-Killer" group, with destroyers employed as killers. Several features aided the P-2 in its hunter role:

    Sonobuoys could be launched from a station in the aft portion of the fuselage and monitored by radio

    Some models were equipped with "pointable" twin .50 caliber machine guns in the nose, but most had a forward observation bubble with an observer seat, a feature often seen in images.

    The AN/ASQ-8 Magnetic Anomaly Detector was fitted in an extended tail, producing a paper chart. Unmarked charts were not classified, but those with annotations were classified as secret.

    A belly-mounted AN/APS-20 surface-search radar enabled detection of surfaced and snorkeling submarines at considerable distances.

As the P-2 was replaced in the US Navy by the P-3A Orion in active Fleet squadrons in the early and mid-1960s, the P-2 continued to remain operational in the Naval Air Reserve through the mid-1970s, primarily in its SP-2H version. As active Fleet squadrons transitioned to the P-3B and P-3C in the mid- and late-1960s and early 1970s, the Naval Air Reserve P-2s were eventually replaced by P-3As and P-3Bs and the P-2 exited active U.S. naval service. VP-23 was the last active duty patrol squadron to operate the SP-2H, retiring its last Neptune on 20 February 1970, while the last Naval Reserve patrol squadron to operate the Neptune, VP-94, retired its last SP-2H in 1978.

Nuclear bomber

At the end of World War II, the US Navy felt the need to acquire a nuclear strike capability to maintain its political influence. In the short term, carrier-based aircraft were the best solution. Nuclear munitions at that time were bulky and required a large aircraft to carry them. The U.S. Navy improvised a carrier-based nuclear strike aircraft by modifying the P2V Neptune for carrier takeoff using jet assisted takeoff (JATO) rocket boosters, with initial takeoff tests in 1948. However, the Neptune could not land on a carrier, therefore the crew had to either make their way to a friendly land base after a strike, or ditch in the sea near a U.S. Navy vessel. It was replaced in this emergency role by the North American AJ Savage, the first nuclear strike aircraft that was fully capable of carrier launch and recovery operations; it was also short-lived in that role as the US Navy was adopting fully jet powered nuclear strike aircraft.

Covert operations P2V-7U/RB-69A variants

In 1954 under Project Cherry, the US Central Intelligence Agency (CIA) obtained five newly built P2V-7 and converted these into P2V-7U/RB-69A variants by Lockheed's Skunk Works at Hangar B5 in Burbank, California, for the CIA's own private fleet of covert ELINT/ferret aircraft. Later, to make up for P2V-7U/RB-69A operational losses, the CIA obtained and converted two existing US Navy P2V-7s, one in September 1962, and one in December 1964 to P2V-7U/RB-69A Phase VI standard, and also acquired an older P2V-5 from the US Navy as a training aircraft in 1963. Test flights were made by lead aircraft at Edwards AFB from 1955 to 1956, all the aircraft painted with dark sea blue color but with USAF markings. In 1957 one P2V-7U was sent to Eglin AFB for testing aircraft performance at low level and under adverse conditions.

The initial two aircraft were sent to Europe, based at Wiesbaden, West Germany, but were later withdrawn in 1959 when the CIA reduced its covert aircraft assets in Europe. The CIA sent the other two P2V-7U/RB-69As to Hsinchu Air Base, Taiwan, where by December 1957, they were given to a "Black Op" unit, the 34th Squadron, better known as the Black Bat Squadron, of the Republic of China Air Force (|ROCAF/Taiwan); these were painted in ROCAF/Taiwan markings. The ROCAF/Taiwan P2V-7U/RB-69A's mission was to conduct low-level penetration flights into mainland China to conduct ELINT/ferret missions including mapping out China's air defense networks, inserting agents via airdrop, and dropping leaflets and supplies. The agreement for plausible deniability between US and Republic of China (ROC) governments meant the RB-69A would be manned by ROCAF/Taiwan crew while conducting operational missions, but would be manned by CIA crew when ferrying RB-69A out of Taiwan or other operational area to US.

The P2V-7U/RB-69A flew with ROCAF/Taiwan Black Bat Squadron over China from 1957 to November 1966. All five original aircraft (two crashed in South Korea, three shot down over China) were lost with all hands on board. In January 1967, two remaining RB-69As flew back to NAS Alameda, California, and were converted back to regular US Navy P2H/P2V-7 ASW aircraft configurations. Most of the 34th Squadron's Black Op missions still remain classified by the CIA, although a CIA internal draft history, Low-Level Technical Reconnaissance over Mainland China (1955–66), reference CSHP-2.348, written in 1972 that covers CIA/ROCAF/Taiwan 34th Squadron's Black Op missions is known to be in existence but will not be declassified by the CIA until after 2022.

Vietnam War

During the Vietnam War, the Neptune was used by the US Navy as a gunship, an overland reconnaissance and sensor deployment aircraft, and in its traditional role as a maritime patrol aircraft. The Neptune was also utilized by the US Army's 1st Radio Research Company (Aviation), call sign "Crazy Cat", based at Cam Ranh Bay in South Vietnam, as an electronic "ferret" aircraft intercepting low-powered tactical voice and morse code radio signals. The US Army operated the P-2 from 1967 until 1972, flying 42,500 hours with no accidents. Observation Squadron 67 (VO-67), call sign "Lindy", was the only P-2 Neptune aircraft squadron to ever receive the Presidential Unit Citation, flying Igloo White missions sowing seismic and acoustic sensors over the Ho Chi Minh Trail. VO-67 lost three OP-2E aircraft and 20 aircrew to ground fire during its secret missions into Laos and Vietnam in 1967–68. The ROCAF/Taiwan's secret 34th Squadron's RB-69A/P2V-7U ELINT/SIGINT aircraft flew a low level electronic reconnaissance from Da Nang, flying over Thanh Hóa Province on 20 August 1963 to investigate an air resupply drop zone that turned out to be a set trap for a Republic of China Air Force (ROCAF) C-123B airdrop mission 10 days earlier due to the air-inserted agents having been captured and turned. Next year, an air defense radar mapping mission was also flown by 34th Squadron's RB-69A/P2V-7U aircraft into North Vietnam and Laos on the night of 16 March 1964. The RB-69A took off from Da Nang, flew up the Gulf of Tonkin before coasting in near Haiphong, then flew down North Vietnam and the Laos border. The mission was requested by SOG for helping plan the insert or resupply of agents. Seven AAA sites, 14 early warning radar sites and two GCI radar signals were detected.

Falklands War

The Argentine Naval Aviation had received at least 16 Neptunes in different variants since 1958 including eight former RAF examples for use in the Escuadrilla Aeronaval de Exploración (Naval exploration squadron). They were intensively used in 1978 during the Operation Soberania against Chile including over the Pacific Ocean.

During the Falklands War (Spanish: Guerra de las Malvinas) in 1982, the last two airframes in service (2-P-111 and 2-P-112) played a key role of reconnaissance and aiding Dassault Super Étendards, particularly on 4 May attack against HMS Sheffield. The lack of spare parts, caused by the US having enacted an arms embargo in 1977 due to the Dirty War, led to the type being retired before the end of the war; Argentine Air Force Lockheed C-130 Hercules took over the task of searching for targets for strike aircraft.

In 1983, the unit was reformed with Lockheed L-188 Electras modified for maritime surveillance; in 1994 these were replaced with P-3B Orions.

Other military operators

The Canadian version of the Lockheed Neptune (P2V-7) served as an anti-submarine, anti-shipping and maritime reconnaissance aircraft in the RCAF Maritime Air Command from 1955, being fitted with just piston engines initially. In 1957, the Neptunes had two underwing Westinghouse J34 jet engine pods installed. This conversion provided additional thrust for an improved takeoff, increased endurance by allowing higher weights of fuel and generally improved the overall performance of the aircraft. (These pods were fitted with inlet shutters for drag reduction when not in use; similar pods were fitted to US Navy variants.) Armament included two torpedoes, mines, depth charges, bombs carried internally plus unguided rockets mounted externally underwing. A total of 25 Neptunes served with nos. 404, 405 and 407 squadrons. Upon unification of the Canadian Forces in 1968, the Neptune was re-designated the CP-122 and was replaced by the Canadair CP-107 Argus the same year.

The Royal Air Force Coastal Command operated 52 P2V-5s, designated Neptune MR.1s as a stop-gap modern maritime patrol aircraft until the Avro Shackleton could enter service.They were used from between 1952 and March 1957, being used for Airborne Early Warning experiments as well as for maritime patrol.

In Australia, the Netherlands, and the US Navy, its tasks were taken over by the larger and more capable Lockheed P-3 Orion, and by the 1970s, it was in use only by patrol squadrons in the US Naval Reserve and the Dutch Navy. The US Naval Reserve abandoned its last Neptunes in 1978, those aircraft also having been replaced by the P-3 Orion. By the 1980s, the Neptune had fallen out of military use in most purchasing nations, replaced by newer aircraft.

In Japan, the Neptune was license-built from 1966 by Kawasaki as the P-2J, with the piston engines replaced by IHI-built T64 turboprops. Kawasaki continued their manufacture much later than Lockheed did; the P-2J remained in service until 1984.

Civilian firefighting

P-2/P2Vs are currently employed in aerial firefighting roles by operators such as Minden Air Corp and Neptune Aviation Services. The fire fighters can carry 2,080 gal (7,874 l) of retardant and have a service life of 15,000 hours. Neptune proposes to replace them with British Aerospace 146 aircraft which are estimated to have a service life of 80,000 hours and carry upwards of 3,000 gallons of retardant.

"The Truculent Turtle"

The third production P2V-1 was chosen for a record-setting mission, ostensibly to test crew endurance and long-range navigation but also for publicity purposes: to display the capabilities of the US Navy's latest patrol bomber. Its nickname was "The Turtle", which was painted on the aircraft's nose (along with a cartoon of a turtle smoking a pipe pedaling a device attached to a propeller). However, in press releases immediately before the flight, the US Navy referred to it as "The Truculent Turtle".

 Loaded with fuel in extra tanks fitted in practically every spare space in the aircraft, "The Turtle" set out from Perth, Australia to the United States. With a crew of four (and a nine-month-old gray kangaroo, a gift from Australia for the National Zoo in Washington, D.C.) the aircraft set off on 9 September 1946, with a RATO (rocket-assisted takeoff). 2 1/2 days (55h, 18m) later, "The Turtle" touched down in Columbus, Ohio, 11,236.6 mi (18,083.6 km) from its starting point. It was the longest un-refueled flight made to that point – 4,000 mi (6,400 km) longer than the US Air Force's Boeing B-29 Superfortress record. This would stand as the absolute unrefueled distance record until 1962 (beaten by a USAF Boeing B-52 Stratofortress), and would remain as a piston-engined record until 1986 when Dick Rutan's Voyager would break it in the process of circumnavigating the globe. "The Turtle" is preserved at the National Museum of Naval Aviation at NAS Pensacola.

Role Maritime Patrol and Anti-Submarine Warfare
Manufacturer Lockheed
First flight 17 May 1945
Introduction March 1947
Retired 1984 From military use
Primary users United States Navy
Japan Maritime Self Defense Force
Royal Australian Air Force
Royal Canadian Air Force
Variants Kawasaki P-2J


General characteristics

  • Crew: 7-9
  • Length: 91 ft 8 in (27.9 m)
  • Wingspan: 101 ft 4 in (30.9 m)
  • Height: 29 ft 4 in (8.9 m)
  • Wing area: 1,000 ft (93 m)
  • Empty weight: 49,548 lb (22,475 kg)
  • Loaded weight: 73,139 lb (33,175 kg)
  • Max takeoff weight: 79,895 lb (36,240 kg)
  • Powerplant:
    • 2 x Westinghouse J34-WE-36 turbojets, 3,400 lbf (15 kN) each
    • 2 x Wright R-3350-32W Cyclone Turbo-compound radial engines, 3,700 hp (2,800 kW) each

Performance

  • Maximum speed: 403 mph (649 km/h)
  • Range:
  • Combat: 2,200 mi (3,500 km)
  • Ferry: 4,350 mi (7,000 km)
  • Service ceiling 22,000 ft (6,700 m)
  • Rate of climb: 1,760 ft/min (9 m/s)
  • Wing loading: 73 lb/ft (360 kg/m)

Armament

  • Rockets: 2.75" FFAR in removable wing-mounted pods
  • Bombs: 10,000 lb (4,500 kg) including free-fall bombs, depth charges, and torpedoes

End notes