The Cessna went down at Charleroi airport when it developed a problem during takeoff and tried to return, a source told the Belgian newspaper De Standaard.
The Flandersnews.be news website reported the victims were members of one family -- a grandfather, his daughter-in-law and three grandchildren ages 7, 6 and 3, RIA Novosti said.
The cause of the crash had not been determined.
De Standaard said the crash forced the cancellation of five flights and delayed 16 others.
Kate Moss Playboy shoot is classic Playboy, classic Kate
Michelle Rodriguez breaks silence on Paul Walker's death