The Cessna plane hit two adults and a child at an airfield on the approximately 950-metre high Wasserkuppe plateau in the central state of Hesse, reported DPA.
According to the police, the pilot failed to align the plane with the runway for landing and tried to lift off once again, but the aircraft lost power and crashed into a group of passers-by just outside the airfield.
The accident happened at around 2.45pm, in clear weather conditions.
Bild reported that another eight people had been injured. Hesse broadcaster Hessischer Rundfunk said that the pilot was not injured.