This is an example of a United States Navy Type H-3 protective flying helmet. In April 1951, the H-3 became the standard issue flying helmet for the service. The helmet was an update of the Type H-2 and featured a "breakaway" protective shell to enable rapid removal from an injured aviator.
This helmet has no known operational history.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.