Originally nicknamed “Sentinel”. Eight P-3B aircraft were converted into Airborne Early Warning and Control aircraft. In the early 90s, “Control” was dropped from the official designation along with the corresponding “C”, renaming the model “P-3-AEW”. This made it more easily differentiated from the E-3-AWACS operated by the U.S.Air Force. The P-3-AEWs are used by Office of CBP Air and Marine for drug interdiction and homeland security missions.