Russia opens black box of jet downed by Turkey

In the presence of foreign experts, Russian officials on Friday opened the damaged black box of a warplane shot down by Turkey last month, promising a transparent probe into the incident.

Officials warned that the memory card sustained damage as they opened the orange-painted flight recorder, with British and Chinese experts observing the procedure, an AFP correspondent saw.

Wearing lab coats and gloves, technicians used screwdrivers, drills, and even a vacuum cleaner as they opened the device under the watchful eyes of military personnel and dozens of journalists in a live national television broadcast.

A Russian military official points to the flight recorder from the Russian Sukhoi Su-24 bomber shot down by a Turkish jet on November 24, as he addresses the media during a briefing on the black box's decoding in Moscow on December 18, 2015 ©Vasily Maximov (AFP)

"Our specialists extracted the memory card, but unfortunately it sustained mechanical damage," said Sergei Bainetov, the deputy head of flight safety in the Russian armed forces, without elaborating on whether flight data could have been lost.

"The commission will discuss the situation calling upon international observers," he added.

The military said the black box had sustained damage, including multiple scratches and dents, but had not been exposed to the fire at the crash site.

The black box's findings will be revealed on Monday, the air force said.

Sergei Dronov, deputy head commander of the Russian air force, for his part said the device was being analysed "openly for the Russian and international public" after President Vladimir Putin had ordered that it be opened in the presence of foreign specialists.

Moscow and Ankara have been locked in a bitter spat over Turkey's downing of the Su-24 jet on November 24, which led to the deaths of a pilot and another serviceman who attempted to rescue him.

They were Russia's first combat casualties of the Syrian campaign, which it launched on September 30.

Turkey says the Russian jet strayed into its airspace and ignored repeated warnings, while Moscow insisted it did not cross over from Syria and accused Ankara of a planned provocation.

"We have sufficient evidence that proves that the Russian aircraft did not violate Turkish airspace," said Dronov, adding that the downed plane had been flying in Syrian airspace 5.5 kilometres (around three miles) from the border with Turkey.

- Britain, China assist probe -

Dronov said the black box presented to the public on Friday had not been touched since it was recovered from the crash site.

The air force commander said 14 countries had been invited to monitor the investigation but only China and Britain had accepted the official offer.

Some US experts were also present when the black box was opened.

Putin has said an analysis of the black box would help determine the downed jet's flight path and position, which Ankara and Moscow have furiously disagreed upon.

But the Russian leader also warned that no black box finding could assuage Moscow's anger over the incident.

The downing of the jet triggered the biggest crisis in ties between Moscow and Ankara since the end of the Cold War, with Russia slapping a raft of economic sanctions against Turkey.

Defence Minister Sergei Shoigu said the Russian military had retrieved the black box after Syrian special forces "liberated" rebel-held territory where the jet was shot down.

A specialist (L) carries the flight recorder from the Russian Sukhoi Su-24 bomber that was shot down by a Turkish jet on November 24 at a briefing in Moscow on December 18, 2015 ©Vasily Maximov (AFP)