Following an extended fitting-out period at the Charleston Naval Shipyard and a restricted availability at Jacksonville Shipyard for correction of minor construction faults, "W. S. Sims" became fully operational in June 1970, and proceeded to Guantanamo Bay, Cuba, for shakedown training. After a two and one-half month post-shakedown availability at the Charleston Naval Shipyard to correct deficiencies uncovered during shakedown and to install additional equipment, "W. S. Sims" was put to sea in November to evaluate the feasibility of installing the light airborne multi-purpose system (LAMPS). She was the first ship of her class to have a manned helicopter land on her deck and, during the next four days, she successfully demonstrated the capability of these new ships to operate manned helicopters. Upon completion of the testing, the escort proceeded to her home port, Mayport, Florida, for the holiday season.