From Michael Hayde's "Superman Comes To Television" (TAC #14, Summer 1997):
Monday, September 3, was Labor Day. The cast received a week off while Maxwell, Luber, Ellsworth, and perhaps Carr and Sholem would finish the remaining scripts and find ways to get the budget down for the final nine. One solution was for Ellsworth to write a script which would utilize only a handful of set for a quick, easy shoot ("The Human Bomb").

There was another week-long break before shooting resumed on the final five episodes. At some point, George Reeves reported to the Process Stage and, under Danny Hays' supervision, was filmed in front of a white screen. These shots would be sent to Studio Film Service where Jack Rabin would create the traveling matte flying scenes for the twenty-four episodes. (See "How They Made Superman Fly" by Paul Mandell in TAC #6, Spring 1991 for an excellent article describing the techniques used throughout the series to film Superman in flight.)