Early tours included assignments as Utilities Officer and Activity Civil Engineer at Naval Station, Rota, Spain; Staff Civil Engineer at Naval Communications Station, Spain; and Assistant Public Works Officer, Navy Support Facility, Diego Garcia, British Indian Ocean Territory.
Subsequently, he served as a NATO Infrastructure Planner on the European Air Combat Operations Staff for the Commander-in-Chief, U.S. Air Forces Europe/Commander-in-Chief, Central Command, Ramstein, Germany; Operations Officer in Naval Mobile Construction Battalion One, deploying to Europe and the Far East; and Joint Staff Civil Engineer, Defense Nuclear Agency, Washington, D.C., where he provided facility counsel to the Department of State during the Intermediate Nuclear Forces (INF) Treaty negotiations with the Soviet Union. He was also named a permanent member of the original INF inspection team fielded by the On Site Inspection Agency to observe strategic weapons fabrication inside the Union of Soviet Socialist Republics. His next tours were as the Production Officer for the Public Works Center, Yokosuka, Japan and then the Force Environmental Advisor for the Commander Naval Forces, Japan.
Following this, he assumed duties as the Public Works Officer and the Officer-in-Charge of Construction at the Naval Air Weapons Station, China Lake, California, the Resident Officer-in-Charge of Geothermal Programs for the Department of Defense, and the Environmental Program Director for all the Navy's major range and test facilities worldwide. He then served as Director, Navy Housing for family and bachelor quarters worldwide followed by the position of Inspector General, both for the Naval Facilities Engineering Command in Washington, DC. Captain Ritchie is currently the Commanding Officer of the Naval School, Civil Engineer Corps Officers in Port Hueneme, California.
Among Captain Ritchie's decorations are the Defense Superior Service, Legion of Merit, Meritorious Service, Navy Commendation, Navy Achievement, and Navy Expeditionary Medals, and the Combat Action Ribbon.
Andy is married to the former Pamela Lang of Redding, California. They are the parents of three children, Bryon Scott, John Wiley and Sarah Anne.
In 1996, Andy helped found a California non-profit public benefit corporation called Science Against Evolution, of which he is currently the vice president.