The crash was the second in East Siberia involving a MiG-29 fighter in less than two months. In mid-October, a MiG-29 fighter crashed 60 kilometers (37 miles) from the Domna airfield during a regular training flight. The pilot ejected safely.
"We inspected all aircraft of this type after the crash and found traces of corrosion on the tail unit of some of the planes," Lt. Gen. Sergei Bainetov said, adding that tail damage was the most likely cause of December's accident.
"Aircraft with no corrosion were allowed to resume flights," he said.
The official said experts were currently attempting to find what caused the corrosion by conducting "artificial aging" experiments with the remains of the tail units of the MiG-29 aircraft that crashed last year.
"We will need at least two months to make a conclusive report on the causes of the accident because the experiments are quite complex and lengthy," Bainetov said.