Le Duc Tan, a ranger in the South Vietnamese army who had recently been demoted from captain to lieutenant for the theft of two cars in Da Nang, smooth-talked his way past security checkpoints. After taking off from Da Nang in South Vietnam on a regularly scheduled flight for Saigon, the flight was hijacked by Tan, holding two grenades. He demanded to be flown to Hanoi in North Vietnam. For unknown reasons the pilots approached the airfield at Phan Rang but aborted the landing. The aircraft overshot the base leg and initiated a left turn, during which the aircraft lost control. Shortly after that, the airplane plunged to the ground from an altitude of 1,000 feet (300 m), killing all 75 people aboard. Even though the exact cause remains unclear, it has been speculated that the hijacker caused the crash by setting off his grenades after the pilots refused to give in to his demands.