Stingers only have a shelf life (without refurbishment) of about 10 years from what I've read on at a number of sources. By that point in time they are considered fairly unreliable, at best, and quickly deteriorate from there. The US ones given to the Afgans must be pretty near that date by now if not surpassing it. I doubt they were kept in good condition either so they are probably worse than average. It's not just the batteries that go flat either, it is also the rocket motors and warhead fuzes.
Why would you use one against a civilan target anyway. The value of a stinger is such that you'd probably want to use it against something valuable, not just a passenger airline. Besides, Stinger was made to engage low flying, small aircraft or helicopters. It is questionable whether it would be terribly effective against a large airliner. The warhead is just too small and the lock on point (the engine) is out on a pylon. The stingers tended to have some difficulties taking down small aircraft (although they did damage them significantly) so their effect against something as large as an airliner is questionable.
Pongo's correct on the Falklands, the Argentinians have several more Exocets on order but not delivered. They also had a limited number of trained pilots and aircraft that could make use of them. Just about every backwater republic has access to Exocet/Silkworm/Chinese Copies of something, let alone some of the more restricted stuff like Harpoons, Sea Eagle, etc. Add a couple more Super Entards, some more trained pilots and a dozen more Exocets and the Brits would have had more of a problem on their hands.
-Soda
The Assassins.
