The PB4Y-1 was powered by four 1,200 hp Pratt & Whitney R-1830-43s or -65s, and most PB4Y-1s carried a crew of nine to ten, an armament of eight 0.50 in (12.7 mm) machineguns in nose, dorsal and tail turrets and waist mounts, and up to 8,000 lb (3,629 kg) of bombs; some, equivalent to the B-24J model, had Erco nose turrets. PB4Y-1s began to reach the USN in August, some going to the TTSP(PAC), a transitional training squadron, and others to the first operational unit, based in Iceland, which scored its first success against a U-boat on November 5, 1942. Deliveries built up slowly at first, but in August 1943 the USAAF agreed to hand over its anti-submarine B-24 squadrons to the USN, in exchange for an equal number of unmodified Liberators already in production for the USN, and accordingly disbanded the Anti-Submarine Command at the end of that month.
USN experience with the PB4Y-1 led to a navalized version, specifically designed for low-altitude patrol work, this was designated PB4Y-2 with the name Sea Liberator, which quickly changed to Privateer. Incorporating the same outer wing and nosewheel undercarriage as the Model 32, the Model 40 PB4Y-2 was considerably revised and eventually received the new model number 100 in the old Vultee series.
The major structural change was the single tail, but the fuselage was lengthened by 7ft (2.13 m) forward of the wing, the 1,350 hp Pratt & Whitney R-1830-94 Wasp engines lacked turbo-superchargers since the aircraft spent most of their time at low altitude, new nacelles were added and aft engine accessories corresponded to the R-2000, and a new electrical system installed. Eight JATO units could also be fitted. Armament was also rearranged to include twelve 0.50 in (12.7 mm) guns in six turrets, an Erco nose (the first 100 had Motor Products units) and Motor Products tail, two Martin dorsal turrets, and two Erco side blisters. Up to eight 1,600 lb (726 kg) bombs could be carried and the eleven crew, including two electronics operators, had 1,171 lb (531 kg) of protective armor plating. Cabin heating was provided by Convair exhaust heat exchangers.
Three PB4Y-1s (BuNo. 32086, 32095, 32096) were allocated for conversion to XPB4Y-2 prototypes by Consolidated on 3 May, 1943, and all were initially flown without the single tail modification, the first on September 20, 1943. The first two aircraft also retained the standard B-24 engine package. The three were converted to single tail configuration, initially smaller than finally decided upon, in late 1943, and redelivered in February 1944. On October 15, 1943, 660 PB4Y-2s were ordered followed by a second batch of 710 a year later. Deliveries began from San Diego in March 1944 and ended in October 1945 but only a total of 740 (BuNo. 59350 to 60009, 66245 to 66324) were completed as the remainder (BuNo. 66325 to 66394, 66795 to 67054, 76839 to 77138) were cancelled. A transport version of the Privateer was also put into production as the RY-3, under the Consolidated Vultee (Convair) Model 101.
The newly formed VPB-118 and VPB-119 were the first Fleet squadrons to receive the type in August 1944. Overseas deployment began on January 6, 1945, when VPB-118 left for operations from Tinian in the Marianas. Thirteen squadrons were fully equipped by the end of the war, and five more had a combination of PB4Y-2s and Liberators, but no score was made by PB4Y-2s against U-boats.
At least nineteen aircraft were converted to PB4Y-2B standard, capable of carrying two 1,600 lb (7,257 kg) ASM-N-2 Bat radar-guided anti-shipping glide-bombs, one underneath each wing outboard of the engines. On April 23, 1945, VPB-109 launched two Bats against shipping in Balikpapan Harbour, Borneo, the first combat use of the only automatic-homing missile used in the Second World War.
Privateers continued in Fleet service until mid-1954. One regular squadron (VP-28) and two reserve units (VP-772 and VP-871) were used in support of Marine night attacks in Korea, modified to carry up to 250 high-intensity parachute flares as 'Lamp Lighter' aircraft on 'Firefly' missions. Some were used for ELINT operations with thirteen crew, and one from VP-26 was shot down over the Baltic by a Soviet fighter on April 8, 1950.
Other conversions were the PB4Y-2M, for meteorological research with turrets removed and a B-24D-type nose transparency; the PB4Y-2P photographic reconnaissance version used until 1955; the PB4Y-2S with additional anti-submarine radar; and the PB4Y-2K target drone converted by the Naval Air Development Center. In June 1951, all surviving aircraft had the 'B' dropped from the designation. ere redesignated P4Y-2, P4Y-2B and P4Y-2S. Nine aircraft were also transferred to the Coast Guard as PB4Y-2Gs for ASR duties. In the unified designation system of 1962 the PB4Y-2K became the QP-4B, while the sole QP4Y-2, used to ferry personnel between the PMTC at Point Mugu and Saint Nicholas Island, became the QF-4B, although possibly it was already withdrawn from use. No other Liberator variants were redesignated.
Ten PB4Y-2Ss were initially supplied to the French Navy for Flottille 8F (renumbered 28F from late 1953) at Tan Son Nhut, French Indochina, from November 24, 1950, and converted to PB4Y-2B standard for bombing missions. Replacement aircraft for those lost, several in action, and for 24F which was commissioned too late to see operations, brought the total supplied to 24. In March 1956, the unit began to transfer to Karouba, Tunisia, and the Privateers again saw action in the Algerian war of independence from August that year, and also flew missions during the Suez crisis. The last five remaining aircraft were scrapped early in 1961, following re-equipment with the Lockheed P2V-6 Neptune.
Privateers were also used by the Nationalist Chinese AF (one was shot down by Burmese fighters as late as 1961) and the Honduran AF used three aircraft in the transport role until the early 1970s.
A Restricted Certificate (AR-29) was issued for P4Y -2s converted for firebombing by Transaire Spraying Co, Canyon, Texas, with a capacity of 18,000 lb (8,165 kg) of slurry. Known as Super Privateers with a two-man crew and 1,700 hp Wright Cyclone 14s (R-2600s), most conversions have been operated by Hawkins and Powers Aviation of Greybull, Wyoming. Some have also been fitted with nose transparencies taken from North American F-86 Sabre canopies. By 1988 Hawkins and Powers operated five in the fire-fighting role in 1988 and kept the type in service into the new millennium.
Another P4Y-2 was used for agricultural spraying by International Air Applicators Inc. A sole Brazilian aircraft (PT-BEG) was in service in 1963, as was a Mexican example (XB-DOD), and Empresa Latino Americana de Aeronavegacion (ELDA) operated Condor Service freight routes within Chile and to Lima, Guayaquil, San Carlos de Bariloche, Comodoro Rivadavia, and Mendoza, Argentina, the same year. ELDA also carried passengers on a fill-up basis, one of the last users of a converted WW II bomber for passenger work.
The pictured aircraft, coded D67, is flown by Lt.jg Russell Moyer PPC who had picked up D67 at the Consolidated Vultee Factory at Lindbergh Field San Diego, California, December 1944. While assigned to VPB-109 the aircraft was damaged on the ground while parked at Yonton airfield, Okinawa during a Japanese Commando raid on May 24, 1945. Damaged beyond repair it was struck off charge on May 31, 1945."