Malaysia Airlines' flight MH17 was not operating in restricted airspace, according to a preliminary assessment from IATA.
The aircraft lost contact with air traffic control while operating over eastern Ukraine.
Ukrainian upper airspace is divided into five flight information regions: Kiev, Lviv, Dnipropetrovsk, Odessa and Simferopol.
Flight MH17 had been transiting the Dnipropetrovsk FIR eastbound, approaching the Russian border, when it lost contact.
While eastern Ukraine has been the scene of armed conflict, including attacks on low-flying military transports, IATA states that the airspace in which the Malaysian Boeing 777-200ER was flying "was not subject to restrictions".
Crimean airspace, encompassed by the Simferopol FIR to the south, had been the subject of an official warning in April owing to uncertainty over responsibility for air navigation over the territory.
This advice, put forward by Eurocontrol and ICAO, led to operators avoiding planning routes which crossed the Simferopol FIR.
Eurocontrol and ICAO have been working towards quick restoration of normal air traffic control services in the region.