In 1952, the RCAF issued a requirement for an aircraft to replace the aging fleet of Lancaster search and patrol   aircraft. Realizing that the Lancasters could not be expected to soldier on until the arrival of their replacements, the Air Force ordered stock Lockheed P2V7 [1] Neptunes to act as a stand-in until newer aircraft could be delivered. It was an excellent choice since this aircraft was developed specifically for Anti-Submarine Warfare (ASW) service.

When the C-series designators (CTS Control Numbers) for Canadian military aircraft were approved around 1968, the Neptune was going to be assigned CP-122 and around the time it was going out of service. To the crews that flew it, the aircraft would only be known as the P2V7 so the CP-122 designator was retroactive and mainly academic. The designator system was not actually implemented until the May-June 1970 time frame when aircraft started to be repainted. There are also a number of web sites which incorrectly identify the Neptune as designator CP-127.

The Neptune’s arrival coincided with some critical developments in the maritime tactical environment.  One was the advent of the nuclear-powered submarine and the other was the establishment of the USN  SOund SUrveillance System  (SOSUS) which was comprised of a number of hydrophone arrays on the ocean floor off the Atlantic and Pacific coasts. Manning of the USN SOSUS system was augmented by RCN and RCAF personnel.  SOSUS revolutionized ocean surveillance for ASW by adding operations cued solely by shore-based SOSUS stations that used arrays of hydrophones to detect sound transmissions from surfaced or snorkeling submarines as well as surface ships.  SOSUS was comprised of a series of passive hydrophone arrays situated on the seabed along the continental shelf and capable of long-range (50-500 miles) detection of submarines and surface ships cruising in adjacent waters.

Contacts detected by the arrays were transmitted to shore stations, processed and transmitted to ships and aircraft such as the Neptune. Generally called  “pouncers”, they had to search the SOSUS probability area to acquire the contact.  If the submarine was partially or wholly surfaced, it could be spotted visually or by radar.  If submerged, a sonobuoy search pattern was sown by the aircraft to detect the sounds of the submarine’s engines, propellers and turbines.  Submerged boats had greater hull-to-water coupling and hence their sounds were transmitted better into the surrounding water.  Diesel submarines were much noisier when snorkeling because, in addition to their dived machinery running, their diesel engines were also operating to turn the generators that charged their batteries.  Ships could confirm their sonar contacts by directing a Magnetic Anomaly Detection (MAD) equipped aircraft such as the Neptune to overfly their sonar contacts; together they could track a diesel submarine to exhaustion or the ship could direct the aircraft to attack.  The aircraft attack was preferable as it allowed the warship to stay beyond the range of the submarine's torpedoes.  Continental defence was not the only facet of ASW in which the Neptunes were involved.

The annual NATO “New Broom” series of convoy protection exercises were conducted through the latter half of the 1950s, with the RCAF's P2V-7 Neptune squadrons providing part of Canada’s contribution.  Standard patterns flown by ASW aircraft of all services included barrier patrols back and forth along a constant bearing in front and on the flanks of the convoy or task force – variations on the "Adder" and "Crocodile" patrols of the War years.  With their enhanced sensor capability, the Neptunes were called upon to fly combined MAD/sonobuoy barriers to detect a submarine attempting to penetrate the barrier protecting a high value target. Initially, only MAD was used, but because the barrier was several miles long and MAD had a range of only several hundred yards, the submarine could pass through any point on the barrier path before the aircraft could revisit the point of penetration.  Accordingly, MAD only patrols were regarded by the crews as a procedure of last resort.

The Neptune era witnessed the commencement of work on a technique that can be said to have had revolutionary significance to the airborne ASW community. From the outset, sonobuoys used in anti-submarine warfare were passive only—they simply listened and passed on the acoustic information. In the mid-‘50s, the USN began experimenting with an active technique called “explosive echo ranging”, or EER. It was nicknamed “Julie” after a stripper whose on-stage performance made passive b(u)oys active.

EER involved dropping small explosive charges, known as practice depth charges, or PDCs, beside a passive sonobuoy.  If the explosive sound energy struck a submarine, the echo was reflected back to the sonobuoy and transmitted to the sonobuoy receivers in the ASW aircraft.  By modifying the MAD recorder, the time difference between the PDC detonation and receipt of the echo could be measured. By using simple time-distance arithmetic, the range of the submarine from the sonobuoy could be calculated. Intersecting range circles from two or more sonobuoys produced a fix on the submarine.

The RCAF and RCN were keenly interested in the EER concept, and in October of 1956 a Canadian contingent proceeded to Bermuda to conduct more advanced trials with the system.  Involved were a Neptune from the Summerside-based Maritime Proving and Evaluation Unit, a Navy Avenger AS 3M, an S2F Tracker that had been received on loan from the USN, and an RN submarine.  The two naval aircraft were with VX 10. Further developmental work was done, and EER went on to become part of the standard operating procedure on the Neptune.

Initially, all Neptunes came in a midnight-blue paint scheme. This was changed several years later to a grey and white scheme. The first operational squadrons to be equipped with the Neptune were No. 404 and No. 405 squadrons based in Greenwood, Nova Scotia. On May 5, 1958,  407 Squadron at Comox BC became operational with the  Neptune.

When originally acquired by the RCAF, Neptunes sported a dark blue colour scheme.  (DND photo from the collection of Patrick Martin)
There were special jobs that the Neptune performed during its stay in the RCAF. One was during the Suffield Alberta Blast Experiments conducted from 1966 to1967. A Neptune, specially fitted with high speed cameras, timing devices, G-meters, etc., was used as a high level laboratory over the explosion site to aid in the experiments conducted as a joint NATO project for the study of high intensity thermal explosions.

There were also missions in Canada's north where the Neptune was used in the collection of data and photo reconnaissance of vast desolate areas. The aircraft was used because of its long range and stability as well as its rugged dependability in severe climates.

Ray White was based at the Supplementary Radio System station in Frobisher Bay during the 1950's. It was located near the main runway. He recalls the noise from the Neptune. "In the spring of 1955, the USN flew piston engine only Neptunes out of Frobisher Bay for ice reconnaissance as part of the International Ice Patrol.  Their patrol area was the Coast of Labrador and Hudson Strait  and I don't believe they went any further south than Hopewell Cape. Of course, with the only runway located not far from our old HFDF shack,  we would go outside and watch the P2V taking off.  We could see the observer sitting in the nose of the aircraft and, just prior to takeoff one member of the crew would exit the plane to verify that JATO rockets were fitted correctly, re-enter the plane and it would take off, very noisily -- so noisily, in fact, that we had to suspend operations for a few minutes during takeoff. It was a great diversion and break from the monotony of DF operations."

In Canadian service, JATO was not used operationally on RCAF Neptunes. On one occassion at least, it was seen in use only at an air show to produce an impressive amount of smoke and noise and make the Neptune climb like a homesick angel.

A USN Neptune named the "Truculent Turtle" (with additional internal fuel tanks) flew non-stop from Perth, Australia, to Columbus, Ohio, from 29 September to 1 October 1946, a time of 55 hours, 17 minutes, and an un-refuelled distance of 11,235 miles.
Later on, the Neptunes were repainted in this grey and white scheme.  The small jet engine is easily visible on this aircraft, just outboard of the port prop. Although the primary role of the Neptune was anti-submarine warfare, anti-shipping was also considered an important ability. (Canadian Forces Photo) 
Fred Weir, a former RCAF Neptune pilot describes the turbojet engines. "All P2V-7/SP2H Neptune aircraft were manufactured with jet engines and P2V-5s were retrofitted with jets. The exception was the 25 RCAF Neptunes that were ordered without jets, but all necessary hardware except the pylons and engines were built in. All that was necessary to reconfigure our aircraft with jets was to mount the pylons, the engines and cowlings, and to hook up the fuel plumbing and wiring. Around September 1959, Canadian Neptunes began receiving jet engines.

The jet installation raised the All-Up-Weight from 70,000 (which was frequently exceeded by a thousand pounds or so) to 80,000 lbs. The gain in payload was small because the jet engine installation weighed about 6,000 lbs so the aircraft had to carry extra fuel to compensate for the extra weight and extra drag of the jet pods. The aircraft was marginally safer on take-off due to having four engines although single engine performance without jets was adequate. Weight could be reduced by about 3000 pounds by jettisoning full tip tanks.

“Tip Tanks Jettison Doors Open” was an item on the pre-takeoff checklist and the co-pilot’s left hand was never very far away from these levers during heavy takeoffs so that the tanks could be jettisoned virtually immediately. Additionally, the pilot just had to move the undercarriage lever one notch forward of the gear-up position to initiate automatic jettisoning of any armament carried in the bomb bay or on wing stations. In a few seconds, bomb-bay doors would open, stores would be jettisoned safe, and the doors would close. There were a few instances of engine failure on takeoff during the period the Neptune was operated without jets, but there were no instances (to the best of anyone's knowledge) where anyone resorted to jettisoning the tip tanks. Even so, it is a much more comfortable feeling setting there with all that thrust from the jet engines when a reciprocating engine fails on takeoff. The price the crews paid for being in this comfort zone was a very large reduction in operational capability in the form of reduced range and endurance.

The jets were always used on takeoff. A jet, normally on same side as a dead reciprocating engine had to be used to maintain altitude above aircraft single engine weight (67,500 lbs). The pilot opened the jet-pod-doors when the aircraft was operating below 500 feet letting the jets windmill. This enabled a rapid start if more power was needed. Jets were always used at idle setting for landings as a precautionary measure to provide immediate power if it was needed.

Having that extra power was a real novelty when the jets were first installed. Crews used to cruise with one jet lit getting an airspeed of about 250 knots, but, even though avgas was only about 25 cents a gallon in those days, it was an extravagance  that wasn't permitted for very long. Additionally, in operating the aircraft this much above its design cruising speed was putting extra loading on the airframe that it wasn’t necessarily designed to take as a steady diet. Crews affectionately called the J-34's the "Westinghouse fuel dumpers".

The jets did provide a tactical advantage in what was referred to as “Dash Speed”, the ability to get from one place to another in a big hurry when the tactical situation called for it. Other aircraft which were fitted with auxiliary jet engines to improve takeoff performance were the C-119 and the B-50".

Since the Neptune was a mid-wing aircraft, crew had to slide over the wing spar on their bellies to get from front to back and vice versa. The aircraft also tended to break at that point so lore had it that it wasn't a great place to be during forced landings.
As a fitting tribute to a grand old lady of the air that has been flown in such varied circumstances by so many different nations, the P-2000 club was formed in the RCAF in 1966 for the aviators who had the common bond of having accumulated 2,000 flying hours in the P-2 Neptune, a noteworthy achievement that created friendships among P-2 aviators around the world.
"An association of airmen who have logged over 2,000 hours in the Lockheed P2 Neptune aircraft, for the purpose of promoting harmony and goodwill."

Thus reads the first objective of the charter of the "P-2000 Club" formed at No. 407 (MP) Squadron in May of 1966 by Lieutenant-Colonel H. E. Smale, Commanding Officer. From the founding 21 members, the Comox Club swelled to a membership of over 120 by 1968. The second objective, "To foster and encourage the formation of additional branches of the P-2000 Club", was also under way. The first branch was opened at CFB Summerside, P.E.I., in 1967 and a second was authorized and formed at USNAS Patuxent River with VP30 holding the only charter in the United States. There were now P-2000 members in Europe, Australia, Japan, Vietnam, the United States and Canada.

Manufacturer:  Lockheed Aircraft
Overall Length:  91 feet, 8 inches
Wing Span: 101 feet, 4 inches
Height (tip of tail): 29 feet, 4 inches
Empty Weight: 50,000 pounds
Overall Weight:  72, 000 pounds. The Canadian Neptunes were a slightly heavier than the USN version, mainly because the Julie-Jezebel mod was heavier than equivalent equipment carried in the USN version.
Maximum Speed:  390 Kts
Patrol (Crusing) Speed: 170 Knots
Range and Endurance : 2000 miles and a 12 hour endurance. (See this explanation)
Engines:  Two Wright Cyclone R-3350 18 cylinder turbo-compound radial engines, each 3,700 hp with water injection and turning four-bladed Hamilton Standard Holla propellers. In 1959,  two Westinghouse J34-WE36 turbojets were added - 3,400 hp wet each. Because of a 10,000 lb-heavier-takeoff weight, the jets were always used at full power for takeoff because the extra thrust was necessary to get off the ground in a reasonable distance and to climb away if a reciprocating engine failed.
Fuel Load: 20,280 pounds of 115/145 Avgas for both the piston engines and the turbojets. Tip tanks were standard on all versions. P2V-7s were equipped with 200 US gallon tips.
Greenwood N.S service:  March 1955 to June 1959 with 404 and 405 Squadrons.
Crew: – The minimum crew complement was 2 pilots and a flight engineer. The standard tactical crew was 10 because that was the number of approved takeoff/crash positions. Jim Loring remembers a crew of 11 as the normal complement  for 407 Squadron:  2 Pilots, 2 Navigators, 1 Flight Engineer, and 5 to 6 Radio operators.  (The standard Australian Tactical crew in their Neptunes was 11 with one crew member seated with his back to a bulkhead as a crash position). On routine transits, the Radio, Radar and Navigation positions were manned. In tactical situations there were more crew - Nose observer, Radio, Radar, Acoustics/MAD, ESM, and ASW . The ASW position was at the rear of the aircraft where sonobuoys,  charges, and smokes were loaded for use.  The Radio Operators were the "Jack-of-all trades"  type crew member.

ASW Equipment:  APS-20 Radar, Electronic Support Measures (ESM), Exhaust Trail Indicator (ETI), searchlight, Magnetic Anomaly Detector (MAD), passive acoustics. Jezebel (low frequency sound detection and classification) and Julie (explosive echo ranging).
Searchlight: 70 million candlepower.
Weapons:  Torpedoes, bombs, depth charges, mines, rockets.
Total built P2V7 only: 359
Cost: $1,284,400
Comment: The crew often referred to the piston and turbojet engine combination as "2 turning and 2 burning".

There were 8 “armament hard points” on each wing. Jet pylons were hung on the 4 inboard stations on each wing. Armament stores (bombs, depth charges, mines or rockets) could be hung on the 4 outboard stations. RCAF Neptunes were fitted with rockets.

At Summerside PEI, there were ramps on which the nose wheel rolled over when hangaring the aircraft . The purpose was to dip the tail so the collision light didn't get knocked off as the tail came through the door - the clearance really was that close.

Neptune outline drawings. (Courtesy

Fred Weir is very  familiar with the sequence of events in the sole crash of the only Neptune aircraft in the fleet.

"I had been transferred from the unit where it occurred (2MOTU) a short time before the accident and the instructor pilot involved was a personal friend. The aircraft was on a routine training mission with an instructor pilot and an instructor flight engineer along with 2 trainee pilots and a trainee flight engineer. The training exercise called for an engine to be shut down in flight, the propeller “feathered” (the blades rotated to be aligned with the air flow to create minimum drag), and then the shutdown check list completed. The crew would then complete the engine start check list, unfeather the propeller, and restart the engine.

It was standard procedure to start the jet engines whenever an engine was to be shut down in flight. The right engine was shut down and the propeller feathered. The jet engines were set to provide power to compensate for the engine that was shut down. The operating engine was set at 2,300 RPM and normal cruise boost. This is speculation on my part because these were the power settings when they arrived back at the airport to land.

When they were ready to restart the engine is when things started going wrong. The generator disconnected when they attempted to un-feather the propeller with no way for the crew to reset it leaving them with nothing except battery power. It was standard operating procedure to turn off the master battery switch when the last generator fails to conserve battery power for the essential flight instruments and the landing. I don't know whether it was a generator fault that caused the problem or if the crew erred in allowing the battery to become seriously depleted before they turned off the battery master switch. In any case, they arrived back at the airport with a seriously depleted battery.
The crew had no reason to suspect they had a serious emergency. They had good weather, they had sufficient power to maintain altitude, they had only to line up with the landing runway and to continue the approach to a landing. They lowered the landing gear and some flap manually. They fired a red flare to let the tower know they were in trouble. When the pilot considered he was in position to continue the approach on the recip engine only, he called for Battery Master Switch – On and Jet Throttles – Idle, only nothing happened. The jets kept putting out power. The jet throttles were electric and battery voltage was below the threshold for the jet throttle actuators to function. He was now seriously overshooting the runway and had no hope of getting stopped on the runway, so he applied all the power he could to the recip engine to go around. The propeller controls were electric, so he couldn't get any more than the 2300 RPM that had been previously set, a cruise power setting. His situation was still not desperate, he could still do a low-level circuit and try again. And then, the final straw. These jet engines that had kept him from making a successful landing by refusing to quit now quit on their own. The control switches that actuated the jet fuel shut off valves were “fail-closed”; when the battery voltage fell below the threshold voltage for the switch, it dropped out to the closed position and there was still enough voltage to motor the valves closed shutting off the fuel to the jet engines. He now had insufficient power to maintain altitude. There was no place to go except down.

He told me he “ran out of altitude, airspeed, and ideas, all at the same time”. He said he just pulled the control yoke back to his gut and held on. It looked as if a stall may have started to develop, a wing tip dug in spinning the aircraft around and it stopped in a hundred yards or so. The fuselage broke in two just aft of the wings and it started to burn. The crew evacuated the aircraft through the pilots overhead hatches without a scratch. They moved away a safe distance and watched it burn".


Greenwood served as home base for the Neptune along with other types as well. RCAF crews flew the Lancaster, a converted Second World War bomber, from several bases on anti-submarine warfare (ASW) operations from 1949 to 1955. The Neptune, an interim aircraft, took over from 1955 to 1960, until the Argus arrived. Although most RCAF squadrons converted to the Argus by 1960, Neptunes continued to operate from CFB Summerside, P.E.I. and CFB Comox, B.C. until 1968.

Neptunes initially equipped 404 and 405 Maritime Patrol Squadrons operating from RCAF Station Greenwood, Nova Scotia and the Maritime Proving and Evaluation Unit. They also operated from Greenwood and later out of RCAF Station Summerside, P.E.I. 407 Squadron at Comox BC also flew Neptunes. With the Argus being delivered in 1957 and the Neptune being stuck off strength 11 years later, this means both aircraft types overlapped service for that period.

The Neptune served from 30 March, 1955 until the entire fleet of  24 remaining aircraft were struck off strength on 31 July, 1968 according to the record cards and other official documents.  CFHQ messages DMFORA6150 092235Z February 1968, DMFORA6181 122200Z March 1968, and DMFORA6184 182135Z March 1968 provided the plan for the Neptune phase-out and Argus redeployment into 407 Squadron at Comox. For planning purposes, 7 April 1968 was the date that Neptune flying was to cease at CFB Summerside, while 1 July 1968 was the final date for Neptune operations at 407 Squadron, Comox. One Neptune remained at AETE Uplands (Ottawa) for a special project until August 1968." Aircraft #24104 flew the last operational Neptune mission on 3 April 1968 and the last public display of a Neptune was at Abbotsford BC in mid August 1968, still in RCAF markings.

"CFHQ message DSM430 162045Z Aug 68 confirmed that there was no museum requirement for a Neptune aircraft. Therefore aircraft serial number 24125, previously held for this purpose, was stripped of the 'Wanted List' items and declared to disposal in the same manner as the rest of the fleet."
The U.S. Navy's last operational Neptune was an EP-2H BuNo147969 which last flew with VC8 from Roosevelt Roads , Puerto Rico and it was the last P2 to fly  with the Squadron as an airborne data link. It arrived in Greenwood on 27 August 1980 and is now on display at the museum. It is fitted with 350 gallon tip tanks. (Photo by Cpl Roger Gallant, Sentinel Magazine) 
The U.S. Navy's last operational Neptune flew into CFB Greenwood, N.S. on August 27, 1980 to take up permanent residence in the museum. Until its final trip north, the twin-engined Neptune maritime patrol aircraft BuNo 147969, flew as an airborne data link with the USN's Fleet Composite Sqn 8, based at Roosevelt Roads, Puerto Rico. The aircraft was graciously donated to "The Association For The Preservation of Land Based Maritime Aircraft" which was incorporated on 15 May 1980. The association displays and maintains RCAF and CF aircraft in their original colours and configurations. The Neptune was  mounted on a pedestal beside a Lancaster already on display near Greenwood's hangar line.

The Museum's Neptune was initially displayed as "24117" in the grey/white scheme, but was later repainted in overall dark sea blue as "24101". An aircraft record card was created for it as "24117", but it was not amended to "24101" when the aircraft was repainted. David Fletcher recalls. "I was the project man for the repainting as VN*101 - the number was picked for two reasons; the first Neptune was 24101 and the letters and numbers were easier to mask off than other codes and numbers!  The DuPont paint for the original USN blue was not available but DuPont gave us an exact match for a GMC truck paint.  Eighteen gallons were acquired from an auto supply jobber in Middleton, Nova Scotia.  Seventeen gallons made it to the base but  one gallon fell off the truck and streaked a portion of the highway in USN blue. The aircraft has since been redone as RCAF*101.

The freshly painted Neptune emerges from the hangar after receiving a fresh coat of dark blue paint in 1989. The electronic antennae are in the wrong places for an RCAF aircraft but the preservation team did not want to remove them for concerns that leaking seals would lead to corrosion.  After the inside of the airframe was stripped of everything, it was sprayed with hot oil. That should keep the aircraft free of corrosion for many years to come. (DND neg #GDC89310 6 from the collection of David Fletcher). 

Crew Positions
Electronics Suite
Other Neptune Photos
You Tube Clip of Neptune Takeoff

[1] The USN designation was P2V-7, but in the existing official Canadian documentation  (such as the Annex to the predecessor of CFAO 36-37) and on the aircraft record cards for the Neptunes, it said P2V7 with no hyphen. That was the RCAF's Type Designator. Hyphens often get dropped from all CAF designations, but the regs are very clear about them being part of the designation, e.g. "CF-188" rather than "CF188". Therefore,  the notation P2V7 is used throughout the Neptune documents.

Credits and References:

1) Jim Loring  <j.s.loring(at)>
2) Ernest Cable - Associate Air Force Historian and  Shearwater Aviation Museum Historian <erncar(at)>
3) Leo Pettipas <lpettip(at)> Associate Air Force Historian. Air Force Heritage and History 1 Canadian Air Division.
Winnipeg, Manitoba.
4) Article titled "Early Cold War Anti-Submarine Warfare Development in Canada" by Leo Pettipas.
5) Bert Campbell <navigator1(at)> , Greenwood Aviation Museum
6) Ian Snow <va3qt-4(at)>
7) Patrick Martin <104655(at)>
8) Greenwood Aviation Museum
13) Sentinel Magazine October 1966 "Hunting the Phantoms of the Sea"
14) Sentinel Magazine July-Aug 1968 "King Neptune".
15) Jeff Rankin-Lowe <siriusproductions(a)>
16) Aircraft Designations Systems
17) Ray White <legerwhite(at)>
18) Fred Weir <fweir(at)>

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Nov 8/09