Jack Armstrong (1947)

Jack Armstrong and his friends attempt to rescue a renowned scientist, the inventor of a revolutionary atomic engine, from the clutches an arch-villain bent on world-dominion by means of a death ray place on board a aircraft capable of flying into the ionosphere. Their quest takes the adventurers to a remote island where they must not only contend with the criminal mastermind's henchmen, but a fierce tribe who have their own reasons for thwarting our heroes.