According to sources who attended it, the meeting was convened by the year-old Transportation Security Administration on the afternoon of Election Day, Nov. 5. It included Adm. James Loy, chief of the agency; President Bush's secretary of transportation, Norman Mineta; representatives of the Office of Homeland Security; and a group of 25 airline CEOs. Gathered in a secure conference room in the Department of Transportation Building in Washington, they heard evidence of the growing and intractable threat that shoulder-fired infrared-homing missiles pose to crowded commercial jets taking off and landing at U.S. airports.

Sources within the White House Office of Homeland Security and the Transportation Security Administration, speaking on the condition of anonymity, told Salon the conference was prompted in part by a recent Senior Executive Intelligence Brief prepared by the CIA, which alerted top Bush administration officials and selected military leaders that terrorists have likely smuggled shoulder-launched missiles into the United States in recent months.

Visual Sighting and Auto-Tracking

The news was ominous for the millions of people who fly on American jets each year: Every commercial flight is susceptible to an attack from terrorists armed with launchers that are small, relatively easy to obtain and surgically accurate. And even after a decade of research at the federal Aviation Research Laboratory in New Jersey, neither the government nor the aviation industry can do much to mitigate the danger.

Gary Stubblefield, who heads the security firm Vantage Systems in Scottsdale, Ariz., describes the shoulder-fired missiles as "aviation's dirty little secret." Todd Curtis, the creator of AirSafe.com and a former Air Force officer and Boeing safety analyst, adds this caution: If a "dedicated person wanted to shoot down a plane, there's nothing to stop them."

The weapons "are a serious threat, [and] not enough is being done to deal with it," retired Adm. Thomas Moorer, who served as chairman of the Joint Chiefs of Staff for President Reagan, told Salon in an interview. "It's a simple thing to do. Airplanes have a schedule. They are at the same spot every day, [and] it's simple to fire [a shoulder-launched missile] from a boat or big truck."

Intelligence and security officials have long known of the danger posed by these missiles, but alarms began to sound after the recent discovery of al-Qaida training videos instructing terrorists how to fire the portable antiaircraft missiles and the capture of thousands of such missiles in al-Qaida camps in Afghanistan.

The FBI issued a detailed bulletin on May 22, which was delivered to state and local police agencies via the National Law Enforcement Telecommunications System. In it, the FBI warned that al-Qaida might be planning to use shoulder-fired missiles -- formally called MANPADS, for man-portable air defense systems -- against commercial aircraft within the United States.

"A Stinger, an American-made second-generation MANPAD system, was used by anti-Soviet fighters in Afghanistan during the 1979-1988 Soviet occupation of that country," the advisory said. "Al Qaeda operatives and Taliban militia members are believed to possess a number of functioning Stinger missiles ship [sic] to Afghanistan during the 1980s.

"Given al-Qaida's demonstrated objective to target the U.S. airline industry, its access to U.S. and Russian made MANPAD systems, and recent apparent targeting of U.S.-led military forces in Saudi Arabia, law enforcement agencies in the United States should remain alert to potential use of MANPADS against U.S. aircraft."

The FBI's concern is well-founded. Shoulder-fired missiles have already been used to shoot down commercial aircraft outside the U.S., and the respected Jane's Intelligence Review reported last year that they are now in the hands of up to 27 terrorist groups. Reports from the CIA, State Department and other government agencies show that shoulder-fired missiles have already hit at least 42 civil aircraft since the 1970s. Of these, 29 aircraft -- 69 percent of the total -- were shot down. These attacks have killed well over 900 air travelers -- more than all the victims of notorious Palestinian terrorist Abu Nidal. Shoulder-fired missile attacks on civil aircraft have been launched from land and from water, upon takeoff and landing, and at altitudes reaching to 11,000 feet. While most of these attacks have occurred outside North America proper, the weapons have been used in Central America. The prospect of a shoulder-launched missile attack was a major concern of the FAA during the 1996 Olympic games in Atlanta.

During the Cold War, both the United States and the Soviet Union freely distributed the portable missiles to allies and client states around the world. Introduced during the Vietnam War, these weapons first gained widespread fame in the war between Afghanistan and the former Soviet Union, where U.S.-supplied Stingers are credited with turning the tide against the Soviets. Of the more than 900 Stingers supplied to the Afghan rebels, many were never fired and remained available for use or trade. Unfortunately, these leftover missiles are not the only source that supplies the black market. In recent years, sophisticated new shoulder-launched missiles have been flowing into the world's arms markets.

In the mid-1990s, the international concern over the proliferation of shoulder-fired missiles led to the Wassenaar Agreement, an arms-control "honor system." Wassenaar does not prevent the sale of these weapons but instead promotes the "transparency" of arms sales to curb improper weapons transfers. Although well-intentioned, Wassenaar has failed to thwart black-market sales. Even when they're sold to legitimate governments for self-defense, there is no guarantee that such missiles will remain secure. In 1998, soldiers in the former Soviet republic of Georgia staged an uprising and seized a cache of the shoulder-launched missiles. Likewise, Chechen rebels obtained their initial supply of shoulder-fired missiles by overrunning Russian arsenals.

Even U.S. stockpiles are not completely safe. After completing an inspection of U.S. military storage depots, the General Accounting Office concluded that inventory control of domestic shoulder-fired missile stockpiles has been so poor that the military could not account for hundreds, and perhaps thousands, of its portable missiles. One Army official quoted by the GAO said that it would be "pure luck" if none of the missiles were lost. Regardless of their source, shoulder-fired missiles are small enough to easily smuggle into any country, including the United States, and they're available on the black market for under $100,000 each. That's well within the reach of deep-pocketed terrorist groups, many of which earn hundreds of millions of dollars a year by dealing drugs and engaging in other illegal activities.

These Type Ranges of Engagement are Still Realistic

During a classified briefing at the annual Aircraft Survivability conference in Monterey, Calif., in 1999, an FAA official described the threat from shoulder-launched missile systems and the difficulty in getting airlines to address the threat. A subsequent report from the National Defense Industrial Association, which sponsors the conference, described this presentation as "sobering" and noted "a definite need to reduce vulnerability" of commercial aircraft to the missiles.

"The small size and portability of these missiles make them a lethal threat, especially in takeoff and landing corridors," the authors warned. "Since there have been no confirmed incidents in the U.S., it is difficult to convince aircraft manufacturers and airline companies of the potential cost benefits to making the aircraft less susceptible and less vulnerable to MANPADS through implementation of warning systems and [infrared countermeasures]."

What worries federal officials is that shoulder-fired missiles are so easily obtained, so easy to smuggle, so small and accurate -- and that that the government can currently do little to defend commercial jets against them. By comparison, detecting bombs and knives in luggage is child's play.

Shoulder-fired missiles are self-contained weapons systems, typically 5 feet long and weighing less than 35 pounds. These sophisticated "fire and forget" missiles are easily concealed in shipping containers, aboard a small boat, even in the trunk of a car. A lone terrorist armed with a shoulder-fired missile can destroy an aircraft within seconds after launching the attack. If a plane survives the initial attack, the attacker can attach a new missile tube to his "grip stock" launcher and fire again while the target aircraft is still within range.

Traveling at more than 1,500 miles per hour, a typical shoulder-launched missile can destroy an aircraft from up to four miles away. Early models of these weapons systems had a maximum altitude of around 10,000 feet. The latest generation of shoulder-fired missiles can travel 15,000 feet or higher. Under existing FAA flight rules, aircraft approaching U.S. airports are within range of a shoulder-launched missile attack once they get within 40 to 50 miles of the runway. Put in simpler terms, jets are most vulnerable to attack right about the time flight attendants instruct passengers to turn off their electronic devices.

Even for experienced military pilots flying military aircraft, the first hint that an attack is underway often comes only from the explosion of a missile slamming into an engine, air-conditioning unit or other infrared-radiation-producing device on the aircraft. Even navigation lights emit radiation in the wavelength attractive to these missiles. When equipped with a proximity fuse, the missiles can bring down an aircraft without even making a direct hit.

Dozens of countries have produced hundreds of thousands of these missiles, and many of them have found their way to the black market. Despite international agreements to stop the "improper" sale of shoulder-fired missiles and a CIA operation to purchase them on the black market, these weapon systems remain available to those intent on obtaining them. Despite Afghanistan's status as a pariah nation in the years leading up to the U.S. invasion, the Taliban and al-Qaida were able to secure immense quantities of these deadly weapons systems. Gen. Richard Myers, chairman of the Joint Chiefs of Staff, estimated in October 2001 that enemy forces in Afghanistan possessed between 200 and 300 Stinger missiles, the best-known of the shoulder-fired missiles on the market. On Aug. 6, Pentagon spokesman David Lapan told Salon that U.S. forces in Afghanistan had captured 5,592 shoulder-fired missiles during operations to destroy al-Qaida.

Despite the widespread knowledge of this threat, government officials and airline executives are loath to publicize the danger from infrared-homing missiles. When asked to comment on the efforts by the Transportation Security Administration to protect commercial aircraft from shoulder-fired missile attack, agency spokesman Robert Johnson offered only a terse reply: "We are unable to discuss classified and sensitive information." Despite repeated calls, none of the major airlines contacted by Salon would comment on the threat. Nor would the Air Transport Association, an industry group representing many of the commercial carriers.

The reticence is not surprising. A safe and efficient airline industry is vital to the functioning of the nation's business; the aviation industry employs 1 million people and annually contributes $300 billion to the U.S. economy. Since the attacks of Sept. 11, the airline industry has been reeling. According to the Air Transport Association, the attacks and the economic downturn combined cost the airlines $7 billion last year, even after an infusion of federal cash. And the losses are expected to continue this year. If passengers knew about the danger posed by missiles, they might be less willing to fly, and an actual attack could prove catastrophic to the airline industry.

A terrorist missile strike on a commercial airliner "would have a devastating impact on air travel demand, and an increase in airline insurance and security costs, at a moment in time when they can least afford it," says professor Paul Stephen Dempsey, an air-transportation expert at McGill University in Montreal. Unfortunately for travelers, none of the newly implemented and highly touted security procedures are capable of addressing this threat.

Unlike some of the other threats that emerged with the 9/11 attacks, the government has known about the threat posed by shoulder-fired missiles since at least 1973, when Palestinian terrorists armed with such missiles were arrested in Rome as they waited to shoot down a jet. The first successful use of these weapons to "kill" a commercial aircraft outside a war zone came in 1978, in the skies over Chad. Since then, many government agencies have grown increasingly alarmed by the threat that shoulder-fired missiles pose. While not an everyday occurrence, such attacks are a large enough concern that the FAA's annual Criminal Acts Against Civil Aviation report contains a section that tracks missile attacks.

When asked to describe the likelihood of a shoulder-fired missile attack against commercial aircraft within the continental United States, one official within the intelligence community, who asked not to be named, said that it is an absolute certainty that an attack will occur. The only question is when, he said. "Some of us are surprised that it hasn't already happened."

Because of the increased threat to its commercial-size aircraft due to the proliferation of sophisticated shoulder-fired missiles, the Air Force is starting to replace its standard missile-detection and countermeasures systems with LAIRCMs (large aircraft infrared countermeasures), which use laser jammers to disorient an attacking infrared-homing missile. In contrast to military aircraft, most civilian aircraft lack the countermeasures systems necessary to ward off a missile attack. There are two exceptions: Israel's El-Al Airlines, and some of the private jets owned by corporations and wealthy individuals.

The likelihood that any aircraft will be lost in a missile attack is dependent on a multitude of design factors. Nonetheless, analyses of man-portable missile attacks show that as a group, commercial aircraft (as opposed to small jet fighters that are specifically designed to detect, evade and withstand such missiles) have as much as a 70 percent chance of being lost if hit by a single missile. If an attacker succeeds at striking twice, the likelihood of downing an aircraft approaches 100 percent.

Even though small commercial aircraft are more likely to be lost in a shoulder-fired missile attack, two of the jet aircraft most familiar to American travelers have proven surprisingly vulnerable: Of the five Boeing 727s and 737s that have been hit by shoulder-launched missiles, three have been shot down, and in one of them 130 people died just after takeoff in Angola.

Despite the demonstrated risk that these missiles pose, no meaningful changes have been made to commercial aircraft design or flight operations to reduce it. While the president and other officials travel on aircraft equipped with countermeasures systems that protect them against a missile attack, most Americans do not. "The threats are real and the countermeasures exist," a retired government anti-terrorism expert told Salon, speaking on the condition of anonymity. "Some of us are perplexed as to why a greater sense of urgency hasn't been demonstrated in securing our airspace."

The low priority placed on protecting commercial jets from shoulder-fired missile attack is eerily similar to the debate over the need to strengthen cockpit doors before 9/11. For decades government officials and the airlines knew that the cockpit doors were vulnerable to being broken down by a determined terrorist or a rowdy drunk. Still, nothing was done to fix the problem until thousands had died. Airlines may be reluctant to respond to the threat, one federal source told Salon, because "it would signify to the insurance companies that the airlines believe that it was a significant threat to their daily operations, allowing them to increase the premiums."

Daniel Benjamin, the former director for counter-terrorism for the Clinton White House's National Security Council, acknowledged in an e-mail interview that the threat might also have implications for the airlines' legal liability in the event of a missile attack. "No shortage of studies have been done," Benjamin said, "and up till now, the industry has been unwilling to consider paying for the defensive measures. In the post-9/11 environment, with Washington dictating more in the way of security improvements, there needs to be another look at the issue. With many airlines facing huge financial problems and some staring at insolvency, the problem of paying for the improvements -- which is considerable -- is not going away."

There are a variety of ways to reduce the likelihood that an aircraft will be hit by an infrared-homing missile and to prevent the loss of an aircraft that suffers a hit. One of the basic techniques is to reduce the ability of the missile "seeker" -- the electronic component that homes in on the targeted aircraft -- to "acquire," or lock on to, the intended target. Most shoulder-fired missile seekers use an infrared guidance system that detects the radiation that aircraft emit in the form of light and heat. Navigation lights, air-conditioning units, and aircraft engines all emit infrared radiation that a seeker can detect and lock on to.

Over the years, the military has developed a number of techniques for deflecting shoulder-fired missiles from its aircraft. One is for low-flying aircraft to disperse red-hot flares. Unfortunately, newer shoulder-fired missiles are able to distinguish an aircraft from a flare. Flares also have the drawback of triggering fires when they land on combustible materials. The military has also experimented with using "obscurants," fine metallic or chemical particles dispersed from an aircraft to prevent the missile seeker from locking on to it, and it is investigating the feasibility having an aircraft tow infrared decoys behind it. The military has also used "thermal management" -- suppressing the amount of emitted infrared radiation and thereby presenting a smaller infrared "signature" -- to reduce the likelihood that the infrared seeker will lock on to its intended victim. This in turn reduces the effective operating range of the missile.

Unfortunately, these techniques are not of practical use for commercial aircraft. One could imagine the outcry from people whose businesses or homes lie in airport approach and departure corridors if each of the thousands of daily commercial flights dropped dozens of flares upon takeoff and landing, or spewed fine metallic or chemical particles into the air along those same routes. Thermal management is also of minimal use in protecting commercial aircraft. In contrast to military aircraft, designed from the beginning to present small infrared signatures, commercial aircraft have huge signatures. Additionally, modern shoulder-fired missiles are programmed with sophisticated guidance systems that nullify aircraft designers' attempts to guide infrared-homing missiles to less deadly impact points.

Aircraft are highly sophisticated machines in which the loss of certain critical components eliminates a pilot's ability to control the aircraft. Aviation engineers have designed modern aircraft with redundant critical components to protect planes from crashing due to the failure of one of those components, from a missile warhead detonation or simple mechanical failure. According to Air Force publications on aircraft "survivability," one protective strategy that aircraft manufacturers can implement is to disperse these redundant critical components around the aircraft, while simultaneously keeping them away from likely missile-hit locations. Having a backup component does little good if both the primary component and its backup get destroyed in a missile attack.

Other engineering modifications can improve the survivability of an aircraft struck by a missile. Among the design modifications that airlines could make: