Here is an e-mail I sent some friends,before reading your comments.
If you are thinking of downing an airliner using an inexpensive Strela-2 launcher, here is some advice from an expert,commenting on the rockets missing the target which was an Israeli airliner. - Tom
"The Strela-2 consists of a shoulder-mounted, reusable launcher fitted with an individual rocket. The rocket has a nitrogen-cooled heat-seeking system and will not fire until it has locked onto a heat-emitting target. But the heat-seeking system requires time to adjust its flight and hit its target - if the target is less than 500 metres away, it can miss.
"I think the terrorists were incompetent. If they had waited until it was higher they would probably have succeeded," says O'Halloran.