The Malaysia Airlines jet was flying far above the range of conventional portable anti-aircraft launchers when it was destroyed Thursday — but it was well within the altitude range of the powerful Buk missile-launcher.

That Russian-made system was blamed by an adviser to Ukraine's interior minister for the catastrophe, and defense experts said one could have fallen into the hands of separatist pro-Russia rebels fighting Ukrainian government forces.

A launcher similar to the Buk system was seen earlier in the day by Associated Press journalists in a rebel-held section of eastern Ukraine — lending credence to concerns that the rebels have more powerful weaponry than had been believed.

Defense experts believe Ukrainian government forces may have abandoned Buk systems when retreating from the area, giving the rebels the hardware they sought, or they could have been provided by the Russian government, although analysts say they have seen no proof of such a transfer.

Larry Johnson, a former CIA official with counterterrorism experience, said that if the rebels have a Buk system it is entirely possible that they could have mistaken the civilian airliner for a military transport aircraft before they fired a missile.
"The Buk uses a radar acquisition system for targeting," he said. "These aren't highly trained FAA air traffic controllers. You're tracking something on radar, you see a dot, you get confused. I don't think it was deliberate. I think it was mistaken identity."

He said the Buk is a sophisticated, difficult to operate system used by both the Russian and Ukrainian government military.

Charles Heyman, a retired British military officer who edits the "Armed Forces of the EU" book, said Ukraine obtained the weapons systems from Russia when it became independent in 1991 after the breakup of the Soviet Union. He said the weapons are best deployed near a border being defended, so Ukraine government forces had placed them in areas near the Russian border now controlled by rebels.
"It's possible the rebels took over one or two," he said, referring to both the SA-11 and SA-17 Buk systems.
He also said the Buk's radar doesn't give its operator the same kind of information that air traffic radars provide, which could have led to rebels mistakenly targeting a civilian plane.
"The sophisticated air traffic radars that the Kiev government have got and that the Russian government have got would pick up these civilian aircraft squawking all the time saying 'I'm a civilian,'" he said. "But something like a Buk missile launcher with its own battlefield radar would probably only pick up an aircraft and not pick up the fact it was a civilian aircraft."