This is an example of a standard United States Air Force officer's service cap of the early 1970s.
This particular cap was worn by Brig. Gen. Charles "Chuck" Yeager. Gen. Yeager is most noted for his exploits flying during World War II and breaking the sound barrier in the Bell X-1. He also had an extensive post-war career in Air Force command postings. In 1966, he commanded the 405th Tactical Fighter Wing at Clark Air Base, the Philippines, whose squadrons were deployed on rotational temporary duty in South Vietnam during the early years of United States involvement in the Vietnam War. With the 405th he flew 127 missions. In February 1968, returned the the United States and took command of the 4th Tactical Fighter Wing at Seymour Johnson Air Force Base, North Carolina. In July 1969, he was promoted to brigadier general and was assigned as the vice-commander of the Seventeenth Air Force.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.