He enlisted in the United States Navy on 13 September 1927 and attained the rate of Radioman First Class on 16 February 1938.

He died in his PBY Catalina aircraft at Jolo Harbor, Philippines on 27 December 1941, as he remained bravely at his post in the burning, gasoline-flooded radio compartment.

When stationed in home waters, Pettit trained periodically at Montauk Point, New York, and Casco Bay, Maine.

She also called at the ports of Cherbourg and Le Havre, France, and Plymouth, Liverpool, and Southampton, England.

After V-E Day, Pettit proceeded via Guantanamo Bay, Cuba, the Panama Canal, and San Diego, California, to Hawaii, arriving Pearl Harbor 25 July.