Dean "Diz" Laird entered the Aviation Cadet Program of the U.S. Navy on January 2, 1942, was commissioned an Ensign on August 11, 1942, and was designated a Naval Aviator at NAS Miami, Florida, on October 21, 1942. His first assignment was as an F4F Wildcat and then F6F Hellcat pilot and assistant gunnery officer with VF-4 at NAS Norfolk, Virginia, from November 1942 to March 1943, aboard the aircraft carrier USS Ranger (CV-4) from March 1942 to December 1943, at NAS Quonset, Rhode Island, from December 1943 to May 1944, at NAAS Ayer, Massachusetts, from May to July 1944, at NAAS Hilo, Hawaii, from July to September 1944, aboard the aircraft carrier USS Bunker Hill (CV-17) from September to November 1944, and aboard the aircraft carrier USS Essex (CV-9) from November 1944 to March 1945. During this time, Lt Laird was credited with the destruction of 5.75 enemy aircraft in aerial combat, plus one damaged in the air. He shared in the destruction of a German Ju-88 and an He-115 off Norway in October 1943, and the rest of his air victories were against Japanese aircraft in the Pacific Theater, making him the only Navy ace to have scored air victories against both Germany and Japan.