The Dutch Safety Board report into the July crash of Malaysia Airlines flight MH17 over eastern Ukraine sheds little new light on who was responsible for bringing down the plane and killing the 298 people aboard. That is in part because it is a preliminary report, intended to outline the progress of the investigation, not draw conclusions.

It is also because it is authored by a safety board and intended primarily to draw lessons for general aviation safety rather than apportion blame. Most importantly, the investigation has so far been a remote one. DSB investigators have not been able to visit the crash site for a forensic examination because their safety could not be guaranteed in a conflict zone largely under rebel control. However, the report does put an official imprimatur on some aspects of the disaster that have been unofficially surmised up to now, and fills in some of the details of the last minutes of MH17.

1. The pilots were not told to fly lower

As the plane approached eastern Ukraine at 12.53pm, responsibility for its flight path passed to air traffic control at Dnipropetrovsk. The controllers asked the pilots to climb from 33,000ft to 35,000ft to keep away from other airliners in the area but the "crew replied they were unable to comply and requested to maintain at [33,000ft]". As a result, other air traffic was asked to climb to 35,000ft. The reason for MH17 not being able to climb is not spelled out, but it could be because of weather. There were some thunderstorms in the area. In fact, at 13.00, according to the report, the flight turned slightly to the left "due to weather", 20 minutes before it was brought down. This contradicts at least one of the conspiracy theories in circulation that the plane was told to fly lower than planned by Ukrainian air traffic control.

2. MH17 made no distress signals

The flight data recorder and digital cockpit voice recorder both stopped at 20 seconds past 13.20. No alerts or alarms can be heard or any sign of distress. The last voice communication from the cockpit came 24 seconds earlier – an acknowledgement of the latest routine course instructions from air traffic control. Unable to raise MH17, Dnipropetrovsk asked the next air traffic control centre along the route, at Rostov, if it could see the plane on its screens. Controllers replied: "No, it seems that its target started falling apart."

3. 'High-energy objects' brought the flight down

The fuselage was pierced from the outside by large numbers of "high-energy objects". The cockpit seems to have been particularly badly hit, above the level of the cockpit floor. The DSB investigators have not been able to recover or study any of the objects that penetrated the plane. The report does not speculate on the origin or nature of the objects, but the findings would be consistent with a fragmentation warhead, like the one carried by the Buk anti-aircraft missile, most widely thought to have been involved in the shooting down of the plane.

4. The front fell to the ground first

The plane fell apart in the air with the front parts breaking off first and plummeting to the ground. The result was that parts of the rear and centre of the plane, which kept moving forward, were found further east than the front.

5. MH17 was flying above the minimum altitude

Air traffic restrictions had been in force over eastern Ukraine since 1 July, because of the conflict. As of 14 July, the minimum altitude was raised to 32,000ft. MH17 was flying 1,000ft above that. About 90 minutes after the downing of MH17, Ukrainian air traffic restrictions over eastern Ukraine were changed to stop civilian airliners flying over at any altitude. The question raised by the tragedy, but not explicitly framed in this report, is whether all civilian aircraft should have been banned at all altitudes, given the presence of such fearsome weapons in the area. International aviation organisations have since set up a task force to review how restrictions are set, in light of the disaster.