This flight cap was used by Bernt Balchen in 1933 when he served as the pilot for Lincoln Ellsworth's first attempt at a transantarctic flight. The venture failed, however, because their aircraft, the Northrop Gamma Polar Star, was damaged when the ice floe on which it was resting broke apart.
This object is on display in Thomas W. Haas We All Fly at the National Air and Space Museum in Washington, DC.