AS INTERNATIONAL investigators finally gain access to the wreckage of Malaysia Airlines Flight MH17, they begin a complex process that experts say could hopefully reveal what happened and who is responsible.
Though the site looks like a mess of burnt metal and plastic, there is a surprising amount that investigators can learn.
One thing they can determine from the debris is the nature of the explosion that took down the plane.
Mr Richard Aboulafia, an aviation analyst from the Teal Group told The Straits Times: "The important thing is to find out what this explosion was like. Was it equipment failure or was it a missile strike?"
Given the widely scattered wreckage, most experts are of the opinion that the crash was either caused by a bomb on the flight or a missile.
Mr Aboulafia added that investigators will also be able to tell if "it's an internal or external explosion from the shape of the damage and the blast area".
For example, experts will want to see if the debris around the point of impact points inwards or outwards.
"A penetrating warhead entry point or nearby proximity detonation will create inward explosion metal characteristics," said Mr Michel Merluzeau, managing partner at aerospace consultancy G2 Solutions.
The United States has already said it has evidence that pro-Russian rebels in Ukraine were behind Thursday's disaster, and its intelligence suggests that an SA-11 missile system took down the flight which was cruising at 33,000 feet, killing all 298 on board.
Another piece of evidence that investors will be looking for, said Mr Aboulafia is traces of propellant from the missile.
"That's what gets you to that sort of altitude, and it's a chemical that is definitely tested for," he added.
And when that is found, it can point to what sort of explosive it was and even where or by whom it was manufactured, said experts.
Autopsies of the bodies too will be able to detect explosive residue for those in close proximity to the blast, said Mr Scott Hamilton, managing director of aviation consultancy Leeham.
If damage was largely confined outside the fuselage, "an autopsy will tell", said Mr Hamilton.
One big concern for experts though, is how much the evidence has degraded by being left out in the field.
They point out that chemical residue will deteriorate rapidly when exposed to the elements as they are in this situation.
Said Mr Hamilton: "The longer the wreckage is exposed to elements or tampered with, the harder an analysis may become."
There is also the worry that rebels and other untrained individuals have already tampered with evidence.
Journalists too have been criticised for walking through the crash sites and picking up or going through debris.
Mr Keir Giles, a former pilot and director of the Conflict Studies Research Centre at thinktank Chatham House, said: "As with any air crash investigation, establishing a true and objective picture of what happened - and in what sequence - can depend on reconstructing the crashed aircraft down to the tiniest detail."
This article was first published on July 23, 2014.
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