He transferred to the staff of Commander, Amphibious Force, United States Atlantic Fleet, embarked in USS Mount McKinley (LCC-7) in August 1959.

Following that tour, he went back to the schoolhouse for Radioman "B" school and was assigned to Representative, Commander East Force/Naval Control of Shipping Office.

Upon completion of a tour aboard USS Forrestal (CV-59), which included an extended ten-month deployment in the Mediterranean Sea, he served as an instructor at Radioman "B" school in United States Naval Training Center Bainbridge.

Plackett was selected for the associate degree Completion Program in April 1971 and was advanced to senior chief petty officer while attending classes at Pensacola Junior College.

Following a second tour on the Forrestal and his selection as master chief petty officer, he assumed duties as Director of Communications School, Fleet Training Center, Norfolk, Virginia.