Phantom in the Sky is the story of a Radar Intercept Officer (RIO) in the back seat of the supersonic Phantom jet during the Vietnam War—a unique, tactical perspective of the “guy in back,” or GIB, absent from other published aviation accounts. During the time of Terry L. Thorsen’s service from 1966 to 1970, the RIO played an integral part in enemy aircraft interception and ordnance delivery. In Navy and Marine F-4 Phantom jets, the RIO was a second pair of eyes for the pilot, in charge of communications and navigation, and great to have during emergencies. Thorsen endured the tough Platoon Leaders Course at Quantico and barely earned a commission. He underwent aviation and intercept training while suffering airsickness issues—and still earned his wings. Thorsen joined the oldest and most decorated squadron in the Marine Corps, the VMFA-232 Red Devils in southern California, as it prepared for deployment to Vietnam. In combat, Thorsen felt angst when he saw the sky darken around him from anti-aircraft artillery explosions high above the Ho Chi Minh Trail. On his first close air support mission in support of ground troops (the majority of his Marine aviation missions), he witnessed tracers whiz by his …