The Pan-Am Highway, Part One (Superman EP0265)

In this high-flying episode of The Old Time Radio Superman Show, Clark Kent, Lois Lane, and Perry White are embroiled in a mysterious case involving vanished American engineers in the Andes Mountains. As the trio races through the night in a secret, unregistered stratosphere plane, they're called upon by Washington to tackle a riddle that spans continents. With the fate of the missing expeditions hanging in the balance, can Superman unravel the enigma before it's too late? 

Original Air Date: November 14, 1941