Image copyright AP Image caption MH17's black box flight recorders have been handed over by pro-Russian rebels

British air accident investigators will retrieve data from the black boxes of crashed flight MH17, UK Prime Minister David Cameron has said.

This follows a request by authorities in the Netherlands, where the Malaysia Airlines plane had flown from before crashing in Ukraine last Thursday.

The experts, based at Farnborough, will download data from the recorders for analysis by Dutch and Ukrainian teams.

Some 298 people, including 10 Britons, were killed in the crash.

Western leaders accuse Russia of arming separatist rebels in Ukraine, and believe the rebels shot down the Boeing 777-200 airliner with a ground-to-air missile.

But Russia has suggested Ukrainian government forces are to blame.

Mr Cameron tweeted: "We've agreed Dutch request for air accident investigators at Farnborough to retrieve data from MH17 black boxes for international analysis."

The black boxes are due to come to the UK after pro-Russian rebels handed them to Malaysian officials.

The information retrieved by the UK's Air Accidents Investigation Branch (AAIB) would then be sent on to Dutch and Ukrainian investigators, Downing Street said.

Analysis

Image copyright Reuters

Jonathan Sumberg, BBC transport reporter

Why are the black boxes being examined in the UK? The British Air Accidents Investigation Branch (AAIB) tell me they are one of only two so-called "replay units" in Europe with the necessary equipment to listen to what has been recorded on the cockpit voice recorder. The other is in France.

They have the kit to analyse in minute detail what can be heard in the last few minutes of flight MH17. The information is incredibly sensitive so investigators gather in a sealed room so that only those who should be listening can listen.

There are four speakers on the walls creating a surround sound - anything to help the investigators hear exactly what went on. They may even hear any explosion.

The AAIB will not tell me when they expect to get their hands on the black boxes. But investigators are confident that, depending on the extent of the damage, they can retrieve information from the boxes within 24 hours.

One of the boxes records technical information relating to the performance of the aircraft and the other takes down sounds such as pilots' voices and, potentially, an explosion.

The black box is not set up to record something like this David Gleave, Aviation safety researcher

Investigators will be able to collect information as long as there is no damage to the black boxes, which are designed to withstand a plane crash.

But experts say it is not clear how useful the data on them will be.

David Gleave, a former air accident investigator who is now an aviation safety researcher at Loughborough University, said: "The black box may show absolutely nothing of interest at all.

"It's not set up to record something like this. They're set up to record things like human error, what's happening in the cockpit, equipment failure.

"If the missile exploded in close proximity to the plane and the tail was severed fully off it wouldn't have recorded anything from the cockpit at all.

"If it exploded further away and the crew started to fight against it before the plane came down, there may be 20 seconds of data.

"You might get a pulse in the cabin pressure, the controls may have started to vibrate. If it was a heat-seeking missile and exploded near one of the engines you might get vibration recorded on one side but not the other. But it is likely to have exploded very close to the plane."

Image copyright EPA Image caption A satellite image released on Tuesday shows the main crash site of MH17

There have been rumours of people tampering with the black boxes, but Mr Gleave said he did not think this was possible in such a short space of time.

"In this case, if it was a missile attack, it's likely there'll also be lots of physical evidence so how would you remove that or tamper with it? There's no point tampering with the boxes if you couldn't remove the physical evidence as well," he said.

What are black boxes?

The so-called "black box" on MH17 refers to two devices - neither of them black - which are designed to survive a crash.

The flight data recorder records operating information from the plane's systems, storing a range of information such as altitude, airspeed, engine power and the pilot's use of the controls.

The cockpit voice recorder, as its name suggests, records sound in the cockpit and can be vital in determining what happened to a crashed aircraft.

BBC transport correspondent Richard Westcott said he had visited the room at Farnborough where the data retrieval was to be carried out.

He said: "It's quite a phenomenal kind of laboratory where they go in. They seal the door, no-one can have any kind of device that will listen in to the conversation in the cockpit - because it's obviously incredibly stressful if something like that gets out for families and so on - and then they will listen to what was actually happening on board."

Image copyright AP Image caption Crash investigators from Malaysia were among those who inspected the scene on Tuesday

Image copyright AP Image caption Toys and flowers have been placed among the debris as tributes to those who died

Also on Tuesday, Foreign Secretary Philip Hammond joined other EU ministers in Brussels for talks about the crash in eastern Ukraine.

Mr Hammond said EU ministers had agreed to a "clear political commitment to act in response to this outrage" by drawing up a list of people close to the Russian leadership who would be subject to sanctions.

"The cronies of Mr Putin and his clique in the Kremlin are the people who have to bear the pressure because it is only them feeling the pressure that will in turn put pressure on the Russian government," he said.

"If the financial interests of the group around the leadership are affected the leadership will know about it."

The remains of at least 200 victims have arrived in the city of Kharkiv, which is outside rebel territory in Ukraine, and the first aircraft containing bodies is expected to land at Eindhoven airport, in the Netherlands, on Wednesday.

Those killed on MH17 included 193 Dutch citizens.

A Metropolitan Police-led team of officers will go to the Netherlands to help with the process of identifying the victims.