Moscow says the Sukhoi jet's black box was damaged during the shooting down by Turkey from the ground impact and a Turkish missile. On Friday, NATO agreed an air defense package for Turkey along the Syrian border.
The SU-24 fighter jet's orange "black box" flight recorder was opened in front of reporters and diplomats in Moscow on Friday as part of a plan by Russian officials to prove that the military plane shot down by Turkey last month was not operating in Turkish airspace.
The incident, close to Syria's frontier with Turkey on November 24, triggered extreme tension between Ankara and Moscow, with Turkey refusing to apologize, insisting that the Russian jet ignored several warnings to leave its airspace. The surviving Russian pilot disputed this.
Speaking after an examination of the device, Russian military spokesman Sergie Bainetov said: "Our specialists extracted the memory card, but unfortunately it sustained mechanical damage."
Extent of damage not known
Another spokesman, Colonel Andrei Semonov, said the device, which was located near the tail of the plane, had been damaged by the Turkish air-to-air missile as well as by its impact with the ground.
The Russian military said multiple scratches and dents were seen on the "black box" but the device had not been exposed to fire at the crash site. It's not known whether flight data could have been lost.
Officials said the black box had not been touched since it was recovered from the crash site. Experts would try to analyze its contents over the weekend and hope to present their findings on Monday, they said.
A third Russian military spokesman Sergei Dronov said that Moscow had "sufficient evidence that proves that the Russian aircraft did not violate Turkish airspace," adding that the downed plane had been flying in Syrian airspace 5.5 kilometers (roughly three miles) from the border with Turkey.
Video footage shows a burning trail as a plane comes down after being shot down near the Turkish-Syrian border
The downing of the fighter jet led to the deaths of two Russian servicemen, one of the pilots and another soldier who attempted to rescue them. Moscow described the incident as a "hostile act" and later imposed sanctions against Turkey.
NATO backs Turkey
On Friday, Reuters reported that NATO had agreed to help strengthen Ankara's air defenses on its border with Syria, in an attempt to avoid a repeat of the tragedy.
In an exclusive interview with the news agency, NATO Secretary-General Jens Stoltenberg said diplomats would soon decide which aircraft and ships would be sent to the region.
"We have agreed on a package of assurance measures for Turkey in view of the volatile situation in the region," Stoltenberg told Reuters, adding that the plan would likely see the deployment of AWACS surveillance planes, which can monitor airspace for about 400 kilometers (250 miles) and "enhanced air policing including maritime patrol aircraft."
But while supporting Turkey publicly, NATO diplomats worry Ankara is too aggressive and that further incidents could escalate the situation.
Recently, Russia moved its modern S-400 air defense system into Syria, which can hit missiles and aircraft at distances up to 400 km.
mm/msh (AFP, Reuters)