Triangle of Lust (1978)

A young woman named Susi rides on a plane with her lover but the plane "seems to have some technical problems" so she has to jump out. Upon landing, she is kidnapped by a group of bandits and imprisoned in their hideout. She tries to escape multiple times but without success. She meets Markus, a kidnapped person for ransom. They later decide to escape together and fall in love with each other.