According to a legal document: during initial climb the crew noticed chaotic flashing of the light signalling the opening of the cargo door, followed by the depressurization of the aircraft. The crew returned the aircraft to Magadan with the cargo door remaining in the full upright position for the remainder of the flight. After landing ice was found on the actuators for the locks to lock and keep the door in the locked position. In addition, ice and compressed snow was found on the proxitiy switches. The locks were found actually open. The pressure relief hatch at the cargo door was closed. The aircraft did not carry any cargo on the occurrence flight. Rosaviatsia recommended to operators to ensure that the locks, actuators and proximity switches are free of ice and snow before closing the cargo door, in particular during precipitation in low temperatures. After closing the door the ground personnel should monitor the light extinguishing, which indicates eletric power had been removed from the cargo door mechanism after completing the closing cycle.