Ancient Aliens counts down ten terrifying encounters that researchers like Giorgio Tsoukalos and others present as potential evidence of extraterrestrial contact. The episode features incidents including a 1975 case near Zihuantanejo, Mexico, where pilot Carlos de Los Santos reported losing control of his aircraft after three gray, wingless objects allegedly hijacked his plane using magnetic forces, corroborated by Mexican air traffic control radar tracking. The countdown also examines Japan Airlines Flight 1628's 1986 Alaska encounter, unexplained cattle mutilations, a rural Texas incident that left witnesses with physical injuries, and a claimed public abduction witnessed by multiple people. The show argues that the credibility of trained observers—particularly commercial and military pilots with thousands of flight hours—lends weight to these accounts as evidence of non-human technology operating in Earth's airspace.
Mainstream aviation authorities and scientists typically attribute such encounters to misidentified conventional aircraft, atmospheric phenomena, equipment malfunctions, or psychological factors under stress. The FAA and international aviation agencies have investigated pilot UFO reports but generally classify them as unexplained rather than extraterrestrial. For skeptics, the episode offers documented cases with multiple witnesses and occasional radar confirmation that resist easy dismissal, raising genuine questions about aerial phenomena regardless of their origin. The emphasis on trained observers facing career risks by reporting these incidents adds a human dimension that makes the material compelling even when alternative explanations may exist for individual cases.