Up in the Sky (1979)

A young pilot meets a girl and wants to marry her but before that he has an accident and dies. The girl who is now pregnant give birth to a boy but could not raise him. She gives the boy to a rich family and she herself begins to work there as a servant but without revealing her true identity as the child's mother. The boy grows up and he himself becomes a pilot and falls in love with a girl. At the end he finds about the mother and her secret and marry the girl he loves so much.