Objects penetrated aircraft from outside
Malaysia Airlines flight MH17 broke up in mid-air as a result of structural damage caused by "a large number of high-energy objects that penetrated the aircraft from outside", according to the Dutch investigators' preliminary report.
The report into the downing of the plane over eastern Ukraine does not apportion blame or say a missile was fired. But the Dutch Safety Board (DSB) says: "There are no indications that the MH17 crash was caused by a technical fault or by actions of the crew."
The Boeing 777 was blown up in mid-air on 17 July over rebel-held territory in eastern Ukraine, killing all 298 passengers and crew on board.
The black boxes were retrieved intact, with the flight recorders showing a completely normal flight before impact.
Radio communications with Ukrainian air traffic control confirm that no emergency call was made by the cockpit crew.
The pattern of wreckage on the ground suggests that the aircraft split into pieces during flight.
The report shows how easily a different airliner could have met the fate of the doomed plane instead, had the crew of MH17 been able to comply with a controller's request to fly higher in the minutes before it was shot down.
Air traffic controllers were attempting to clear traffic as three other commercial flights, unidentified in the report, were in the vicinity – two other Boeing 777s and one Airbus A330.
At 12.53pm, Ukrainian air traffic controllers at Dnipropetrovsk asked MH17 to climb 2,000 feet to flight level 350 over eastern Ukraine, in accordance with the original flight plan, to clear a "potential separation conflict" with another Boeing 777.
The crew said they were unable to comply, possibly due to weather. Instead, at least one other plane climbed higher.
Just after 1pm the crew, running into bad weather, requested to climb to 34,000 feet – although air traffic control said the plane should keep at the same altitude. At 1.20pm, MH17 exploded in mid-air.
The other plane was not identified by investigators but it is known that a large Singapore Airlines jet, many of which are 777s, was nearby.
Kiev and the west have accused pro-Russia separatists of shooting down the plane with a surface-to-air missile supplied by Moscow. Russia, which denies mounting western claims of direct involvement in the five-month conflict in Ukraine, has blamed government forces for the attack.
Russia, Ukraine, the US, the UK, Malaysia and Australia were all given the politically sensitive report for review, and investigators say they have since amended it before publication.
The report is being issued just days after a ceasefire backed by Kiev and Moscow came into force on Friday to try to end a war that has killed more than 2,700 people and led to at least half a million fleeing their homes.
Tjibbe Joustra, chairman of the DSB, said: "The MH17 crash has shocked the world and raised many questions. The Dutch Safety Board wishes to determine the cause of the crash, for the sake of the loved ones of the victims and for society at large.