The plane seen during last few minutes (N9971R) is a 1960 Beechcraft B95 Travel Air s/n TD-413. Cost when new $49,500.
Both of this episode's out-of-this-world guest actresses played aliens in the final season of Star Trek (1966). Following her memorable role as Batgirl in the third season of Batman (1966), Yvonne Craig played a green-skinned Orion named Marta in Whom Gods Destroy (1969). A few episodes earlier, Susan Howard played a Klingon named Mara in Day of the Dove (1968). Howard went on to featured roles in Petrocelli (1974) in the 1970s and Dallas (1978) in the 1980s.
Bradley Everett's plane (N2773T) is a 1967 Beechcraft 95-C55 (s/n TE-376). Cost when new $68,350. This same plane was seen in previous weeks.
The California Air National Guard aircraft in the opening scene are C-97 Stratofreighters. The design was based on the B-29 Superfortress. C-97 and the KC-97 Stratotanker variant was used in the 1950s and 1960s by the USAF and Air National Guard. One famous variant are the Guppies. C-97s with.an enlarged fuselage that were used to carry rocket ship components.