P2V-5 (P-2E) / model 426

The P2V-5 Model 426 was the most numerous variant produced by Lockheed and would be the basis for the largest number of sub-type modifications developed of any of the Neptune series.

First flown on 29 December 1950, twenty-three Model 426-42-06s (124865/124887) were built. The new P2V-5 replaced the six cannon solid nose cone of the P2V-4 with an Emerson Aero 9B turret armed with a pair of 20mm cannon. The 20mm tail turret as well as the .50 caliber machine gun armed dorsal turret remained unchanged from the P2V-4. The P2V-5 was capable of carrying an 8,0001b load of mines, torpedoes, bombs or depth charges and sixteen rockets on under-wing launch stubs, later reduced to 8 with the addition of the J-34s. An APS-20 radar was mounted in the underbelly position just behind the nose wheel doors.  Beginning with 127759 and subsequent the Aero 9B was replaced by the 12" longer Aero 9C nose.

The wing tip fuel tanks were enlarged and were moved from an under wing tip position on the P2V-4, to the outside center of the wing tips and could carry an additional 350 gallons of fuel in each tank. In an emergency, the new tip tanks could be jettisoned. In addition, the forward portion of the starboard wingtip tank housed a powerful searchlight with a moveable reflector and arc element that was linked by servomotors to the nose turret guns. The port wingtip tank had APS-8 search radar mounted in its forward portion.  

The Wright Cyclone R-3350-30W engines remained unchanged from the P2V-4. The weight of the additional equipment without a corresponding increase in power caused the top speed to drop to 341 mph. However, the added fuel capacity increased the P2V-5's range to 4,750 miles.

147 Model 426-42-11s for the US Navy, the RAF and the RAAF, in which accommodation was provided for an ECM operator, to increase crew size from eight to nine. 

98 model 426-42-13s were built for the US Navy (127781/127782 and 128327/128422) and were fitted during production with a 17-ft (5'18-m) tail 'stinger' extension housing a MAD (magnetic anomaly detection) system. 

80 Model 426-42-15s (131400/131479) had the MAD 'stinger' extension, an observation nose, and the defensive armament reduced to two 0-50-in guns in the dorsal turret.  Beginning with 131400, this model would have the smaller circular 200 gallon tip tanks and the aft station replaced the circular windows with larger rectangular windows.  

The Marineluchtvaartdienst (MLD, Royal Netherlands Naval Air Service) received twelve Model 426-42-16s which were similar to the 426-42-13s (with MAD 'stinger', nose and dorsal turrets) but had revised crew accommodation.  

Finally 64 Model 426-45-15s (131480/131543) which differed from the 426-42-15s in being powered by 3,500 hp R-3350-32W Turbo-Compounds were delivered to the US Navy the last of which was delivered in September 1954.