After flight training, he was designated as a Naval Flight Officer and assigned to Patrol Squadron Forty-Four (VP-44), homeported at Naval Air Station Brunswick, Maine. He flew the P-3C Orion, deploying throughout the Pacific, Indian and Atlantic Oceans, and Mediterranean Sea. His subsequent operational tours include assignment as a Tactical Action Officer on board , to include participation in dealing with the Achille Lauro hijacking and the 1986 air strikes against Libya (Operation Attain Document III). He served as Operations Officer in Patrol Squadron Four (VP-4) at Naval Air Station Barbers Point, Hawaii, deploying to Southwest Asia during Operations Desert Shield/Desert Storm. He had three tours with Patrol and Reconnaissance Wing 1/Task Force 57/Task Force 72, homeported in Kami Seya, Japan. During his earlier tours with Patrol and Reconnaissance Wing 1, Harris participated in Operations Earnest Will and Southern Watch.