Iraqi investigators have determined that a Hawker 850XP executive jet had not been adequately de-iced before it crashed on take-off from an airport in the north of the country.
The accident occurred as the Lebanon-registered twin-engined aircraft attempted to depart Sulaymaniyah for Ankara, Turkey, on 4 February 2011.
Weather data for the time of the crash included a notification of snow.
Iraq's ministry of transport says the civil aviation authority investigation determined that the crew "did not remove" accumulated snow on the upper surface of the wing before departure.
The midsize business aircraft stalled before reaching sufficient speed, and descended, striking the ground almost 2,100m (6,900ft) from the runway threshold, and 40m from the right-hand edge.
It "burned completely", the ministry says, and none of those on board survived. This included two executives from telecom firm Asiacell and two from private equity investor MerchantBridge, as well as three crew members.