From wikipedia: In 1942, after the death of his wife Carole Lombard, Gable joined the U.S. Army Air Forces. Lombard had suggested that Gable enlist as part of the war effort, but MGM was reluctant to let him go, and he resisted the suggestion. Gable made a public statement after Lombard's death that prompted the Commanding General of the U.S. Army Air Forces Henry H. "Hap" Arnold to offer Gable a "special assignment" in aerial gunnery. Gable had earlier expressed an interest in officer candidate school (OCS), but he enlisted on August 12, 1942, with the intention of becoming an enlisted aerial gunner on a bomber. MGM arranged for his studio friend, the cinematographer Andrew McIntyre, to enlist with him and accompany him through training.
However, shortly after his enlistment, he and McIntyre were sent to Miami Beach, Florida, where they entered USAAF OCS Class 42-E on August 17, 1942. Both completed training on October 28, 1942, commissioned as second lieutenant. His class of about 2,600 fellow students (of which he ranked about 700th in class standing) selected Gable as its graduation speaker, at which General Arnold presented the cadets with their commissions. Arnold then informed Gable of his special assignment: to make a recruiting film in combat with the Eighth Air Force to recruit aerial gunners. Gable and McIntyre were immediately sent to Flexible Gunnery School at Tyndall Field, Florida, followed by a photography course at Fort George Wright, Washington State and promoted to first lieutenants upon his completion.
Gable reported to Biggs Army Air Base on January 27, 1943, to train with and accompany the 351st Bomb Group to England as head of a six-man motion picture unit. In addition to McIntyre, he recruited the screenwriter John Lee Mahin; camera operators Sgts. Mario Toti and Robert Boles; and the sound man Lt. Howard Voss to complete his crew. Gable was promoted to captain while he was with the 351st Bomb Group at Pueblo Army Air Base, Colorado, a rank commensurate with his position as a unit commander. (As first lieutenants, he and McIntyre had equal seniority.)
Gable spent most of 1943 in England at RAF Polebrook with the 351st Bomb Group. Gable flew five combat missions, including one to Germany, as an observer-gunner in B-17 Flying Fortresses between May 4 and September 23, 1943, earning the Air Medal and the Distinguished Flying Cross for his efforts. During one of the missions, Gable's aircraft was damaged by flak and attacked by fighters, which knocked out one of the engines and shot up the stabilizer. In the raid on Germany, one crewman was killed and two others were wounded, and flak went through Gable's boot and narrowly missed his head. When word of this reached MGM, studio executives began to badger the Army Air Forces to reassign its most valuable screen actor to noncombat duty. In November 1943, Gable returned to the United States to edit his film, only to find that the personnel shortage of aerial gunners had already been rectified. He was allowed to complete the film anyway, joining the First Motion Picture Unit in Hollywood, California.
In May 1944, Gable was promoted to major. He hoped for another combat assignment but, when the invasion of Normandy came and went in June without any further orders, Gable was relieved from active duty as a major on June 12, 1944 at his request, since he was over-age for combat. His discharge papers were signed by Captain (later U.S. President) Ronald Reagan. Gable completed editing of the film Combat America in September 1944, giving the narration himself and making use of numerous interviews with enlisted gunners as focus of the film. Because his motion picture production schedule made it impossible for him to fulfill Reserve officer duties, he resigned his commission on September 26, 1947, a week after the Air Force became an independent service branch.
Adolf Hitler favored Gable above all other actors. During World War II, Hitler offered a sizable reward to anyone who could capture and bring Gable to him unscathed.
Gable's military awards were the Distinguished Flying Cross, Air Medal, American Campaign Medal, European-African-Middle Eastern Campaign Medal and World War II Victory Medal. He also qualified for and received aerial gunner wings.
Major Gable, rest in peace, and thank you for your service.