The first plane from the L-l049 Super Constellation family to be ordered officially by the USAF was the RC-121C but contrary to appearances, these were not specific aircraft but R7V-1/WV-2s originally intended for the Navy which were part of the contract it signed with Lockheed but were transferred to the USAF during production and to which it gave the designation RC-121D Airborne Early Warning (AEW), an updated version of the RC-121C, with wingtip tanks, additional internal fuel capacity and a crew of 31 personnel. Engines were 3,400hp Wright Cyclone R-3350 75DA1 Turbo Compounds.
The US Navy which had bought two examples of the WV-1 was based on the L-749 at the end of the forties, considered that the experience was conclusive after using these machines to test new combat tactics. Confronted with the new situation caused by the Korean War, it decided to put to best advantage the advances made by the L-1049 being developed at the time at Burbank in order to obtain a tailor made machine with even better performances. The Wright Turbo Compound was recently available and was an economical power plant, particularly at low altitude, and also had the advantage of being used on another type in the Navy's arsenal, the P2V Neptune. Using the same power plants enabled maintenance and spare parts inventory to be facilitated in the future. With this in mind, the US Navy signed a first contract with Lockheed on 14 July 1950, a little more than a year after the first flight of the PO-1W. This was for the delivery of six Connies based on the L-l049A and designated PO-2W, later changed to WV-2 before the plane was even put in service. The first order was followed by further orders so that all in all 142 'Warning Stars' were supplied to the US Navy.