Meteorological conditions did not preclude a safe landing by the South Airlines Antonov An-24 which crashed at Donetsk on 13 February.
Donetsk airport's operator says the crew received "comprehensive" information from air traffic controllers before the accident involving the chartered aircraft.
"Weather conditions at the time allowed the aircraft to make a safe landing," says the operator.
Donetsk is equipped with instrument landing systems on its runway 08/26.
The airport authorities were alerted to the crash by the "absent communication" over the radio, and the emergency rescue services located the aircraft "outside of the runway boundaries". The aircraft was inverted and fire had broken out on the starboard wing.
Donetsk's deputy public prosecutor, Victor Voitsyshen, states that the investigation is examining multiple scenarios.
He states that these include the possibility of "inappropriate" crew actions, technical failure of the aircraft, weather conditions and faulty ground equipment.
But tests for alcoholic intoxication in the crew have proven negative, he says.
The inquiry will also consider the remote possibility of sabotage and is checking data on the people travelling on the aircraft.
Ukrainian reports, quoting Voitsyshen, suggest the aircraft might have struck a mast with its wing before landing.
Flight recorders from the aircraft are being analysed, Voitsyshen says: "Specialists are working with them now."