The government warned airports Friday that portable rocket launchers could be used against airliners in the United States, even though security officials believe the risk of another attempt like the one against an Israeli jet in Kenya is greater overseas.
The possibility of a missile attack is a major concern for commercial airlines operating abroad, especially in Asia and Africa, said Charlie LeBlanc, managing director of Air Security International Inc., a Houston-based aviation security firm that does government consulting work.
In the United States, he said, an attack is more likely to be thwarted by law enforcement and intelligence agencies.
Still, many terrorist groups have access to the shoulder-fired anti-aircraft missiles, with thousands circulating on the worldwide gray arms market. Their relatively small size and three-mile range could make such missiles ideal weapons for terrorists targeting U.S. airliners.
Security analysts have been warning for years about the potential threat posed by terrorists toting shoulder-held missiles. Al-Qaida is believed to have fired them at planes in Saudi Arabia and Yemen, and the Tamil Tiger rebels used them to down a passenger aircraft in Sri Lanka in 1998.
Two missiles that narrowly missed the Israeli aircraft were fired from a four-wheel drive vehicle one mile from the airport, witnesses told police. Investigators there discovered launch tubes from an SA-7, a heat-seeking missile designed 30 years ago that can hit low-flying aircraft within about three miles.
"We're talking about a weapon that doesn't need to be fired on the aircraft grounds to be effective," LeBlanc said.
In the spring, suspected al-Qaida operatives used an SA-7 to try to shoot an American plane taking off from Prince Sultan Air Base, south of the Saudi capital of Riyadh.
The discovery of the attempt prompted the FBI to issue a bulletin to U.S. police departments on May 22, urging them to be vigilant.
The message, though, said the FBI didn't have information indicating al-Qaida was planning to attack civilian aircraft in the United States.
Instead, the FBI said it believed al-Qaida may try to use such weapons against U.S.-led military forces in the Middle East.
Smaller surface-to-air missiles, like the American Stinger or Russian SA-7 Grail, can be carried by a single person and fired from bazooka-like tubes. Many of these track the heat of an aircraft, then fly close and explode.
But most of these only fly a few miles at most and cannot hit high-flying aircraft. Their aim is not precise. And because they have such small warheads, some aircraft can survive a single hit by one of these weapons.
Military aircraft carry flares that can be launched to serve as a decoy heat source to draw off a missile.
The missiles that were believed to have been fired at the Israeli plane were the Soviet-made SA-7, also known by the Russian name Strela-2M. They are older and less accurate versions of the U.S.-made "Stinger" missiles, which the CIA supplied to the moujahedeen warriors fighting the Soviets in Afghanistan during the 1980s.
The SA-7s were introduced in 1967, and first used by the Soviet-backed Egyptian forces against Israel. When U.S. relations with Egypt later improved, some of the missiles were sent to Germany, where U.S. troops trained with them.
"There are just thousands all over the world," said retired Army Maj. Gen. Edward B. Akeson, a senior fellow at the Institute of Land Warfare. "Everybody's got 'em. They're cheap, and it takes only about a day to train a guy on the thing."
Another uncertainty is how many of the more modern and accurate U.S.-made Stinger missiles may have fallen into terrorist hands. According to a comprehensive 1999 study by Alan J. Kuperman, now at the School for Advanced International Studies in Bologna, Italy, some of the estimated 900 to 1,200 Stingers delivered to Afghanistan in the 1980s were skimmed off en route through Pakistan, with some reportedly ending up on the black market. Others were reportedly hoarded or sold to Iran.
Robert Johnson, spokesman for the Transportation Security Administration, said that the agency made sure airport security officials were aware of the missile attack in Kenya and reminded them of the steps being taken to counter the threat of such an attack.
He declined to describe what those steps were, citing security concerns.
The TSA held a classified meeting with airline officials and others in the industry several weeks ago to discuss the danger posed by the missiles, Johnson said.
The agency has jurisdiction over airports from the perimeter fences inward.