The C-47 had just become airborne when it rolled right and left. The bank angle increased to 40 deg as the C-47 continued in a left turn at low altitude. Level attitude was regained near the airport boundary. The aircraft then swung to the right, bounced and collided head-on with a CSA Douglas C-47 (OK-WDB). The registration was reportedly mispainted on the aircraft as VP-YFE. PROBABLE CAUSE: “Loss of control by the Captain, who, when attempting to take-off a heavily loaded aircraft in poor visibility allowed it to become airborne in a semi-stalled condition. This must be attributed to an error of flying technique by a pilot who lacked Dakota experience. The possibility that the following were contributory causes cannot be dismissed: 1) The adhesion of some snow and/or frost to the lifting surfaces; 2) The impairment of the pilot’s judgement through fatigue.”