The payload, range, and performance of the R70-1 transport persuaded the navy that it would make an ideal long range earl warning plane when fitted with search radar and two PO-1W aircraft were procured as developments of the model 749A with search and height finding radar's respectively above and below the fuselage, whose cabin was outfitted as a combat information center. The first PO-1W flew in June 1949 with 2,500-hp Wright 749C-18BD-1 radial, the PO-1Ws were later redesigned WV-1. With the concept validated by the PO-1Ws the navy order its definitive AEW platform on at the basis of the Model 1049 Super Constellation. Originally designated PO-2Ws, the aircraft became WV-2s. Orders were placed for 244 aircraft, but the navy receiver 142 aircraft as 22 were cancelled, eight were delivered as EV-3 weather reconnaissance aircraft, and 72 became US Air Force RC-121Ds. In1962 the WV-2s became EC-121Ks. The WV-2E, a WV-2 conversion, was a flying test bed for equipment scheduled for the W2V-1 AEW version of the model 1649 Star liner with a dish radar dome above the fuselage. The WV-2E remained an experimental type redesigned EC-121L in 1962.