August 6, 2001 Vol. 15 Iss. 31

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Table of Contents


Cost Evaluations Reveal Artificiality Behind Safety & Security Programs

The arbitrary and capricious nature of cost-benefit calculations is nowhere better illustrated than in two recent examples - one involving aviation security, the other addressing a key issue of air safety.

In the security case, cost-benefit was used to justify moving forward with a limited program. In the safety case, cost-benefit was used as the basis for rejection. Both cases provide a depressing illustration of the "commodification" of human life.

The way the calculations were done in the two cases at hand may well undercut the values professed by their sponsoring institutions - a commitment to protecting public safety and security. In the iron logic of cost-benefit, for a safety or security initiative to be pursued, the "benefit" must outweigh "cost." The process, however, is increasingly seen as an impediment to progress, as evidenced by recent complaints about the "irksome" nature of cost-benefit gymnastics, and a growing chorus of suggestions to waive cost-benefit considerations altogether (see ASW, July 23).

And, for sure, cost-benefit can hurt an institution's political and public credibility. Perhaps the most extreme, if not morbidly amusing example, comes from the beleaguered tobacco industry. A cost-benefit study of smokers in the Czech Republic, commissioned and funded by tobacco giant Philip Morris, weighed the costs of medical care, pensions and housing for smokers against the benefits, such as excise taxes from cigarette purchases, and found that the higher mortality of smokers saved the country nearly $150 million annually. The company reaped a whirlwind of scorn for its disregard of "basic human values." The fiasco bears on the airline industry. Here was a tobacco company willing to illustrate how a certain number of premature smokers' deaths could help the Czech government save money. Recall that the airline industry recently was warned that it could wind up "falling into the groove" of the tobacco industry over perceived inaction on the cabin health issue (see ASW, April 9).

The Phillip Morris study illustrates the extent to which a blinkered approach to cost-benefit can backfire when the tidy calculations find their way into the media. There is an object lesson here for the aviation industry: A more cautionary and realistic approach may be in order, as the cost-benefit calculations behind safety and security programs are a matter of public record, and easily found by the assiduous researcher.

One thing emerges from the two case studies at hand. They reveal in stark terms the arbitrary nature of the numbers and the way they can be biased to limit the investment in safety and security. To be sure, resources are not infinite, and safety and security programs must necessarily strike a balance for the industry to be economically viable. Of course, the corollary argument propounded by many experts is that a safer workplace contributes to a more robust and more profitable business (see ASW, May 21).

Before coming to the cost-benefit case studies, it should be noted that these calculations come into play only when new regulations are under consideration, per an Executive Order issued by then-President Bill Clinton in 1993). However, there are notable exceptions to this mandate, even when orders with the force of regulation are involved.

Airworthiness directives (ADs), for instance, are not regulatory changes, and therefore do not fall under the Executive Order. As an illustration, the FAA issued three ADs on July 12 mandating about a quarter-billion dollars worth of inspections and upgrades to strengthen lap joints and other parts weakening from fatigue cracking on B737 airliners. The effort clearly is intended to prevent a repeat of the 1988 explosive decompression of a high-time Aloha Airlines B737. No cost-benefit applies to these ADs, in terms of calculating the number of explosive decompressions that will be forestalled as the primary "benefit" of the costly work entailed by these ADs.

Safety cost-benefit

For the past year, a government-industry task force has been meeting to assess the feasibility of inerting the fuel-tanks of transport category aircraft. A report of its work, to be presented openly at the Executive Committee hearing August 8, concludes that it is not cost-effective to inert the flammable vapors. The methodology behind that assertion is based on a number of sweeping assumptions likely to be challenged (and defended) at this upcoming hearing. The conclusion in this working group's 600-page report was anticipated, based on the tenor of previous committee meetings (see ASW, May 14).

The effort of this so-called Fuel Tank Inerting Harmonization Working Group (FTIHWG) has been focused primarily on dealing with the greater exposure to explosive vapors of airplanes with air conditioning packs located under the center wing tanks. Three heated center wing tank (HCWT) explosions since 1990 highlight the hazard, with the most recent occurring last March at Bangkok, destroying a Thai Airways International B737 (see ASW, April 16). That case is still under examination, but investigators have concluded from the forensic evidence that the tank blew under conditions similar to those of a TWA B747 in 1996 and a Philippine Airlines B737 in 1990.

The National Transportation Safety Board (NTSB) has called for the elimination of explosive vapors in fuel tanks, given the long record of exploding fuel tanks and a casualty toll that now exceeds 500 deaths. An Aviation Rulemaking Advisory Committee (ARAC) concluded in 1998 that inerting was not cost-effective, despite strong indications up to the eleventh hour that the committee likely would endorse some form of inerting (see ASW, July 6, 1998 and July 20, 1998).

The dead letter produced by the ARAC in 1998 led to the formation of the second effort, the FTIHWG. Its effort, now in the final stage, also seems on the way to foundering on the rocky shoals of cost-benefit calculations. The committee's report concludes that the benefit of avoiding another fuel tank explosion is outweighed by the costs of inerting by a factor in the range of 30-to-1 to more than 50-to-1, based on the type of inerting technology. The committee estimated it would cost anywhere from $10-$20 billion to provide inerting protection on existing and newly built aircraft with center wing tanks. Depending upon the technology, the 132-253 lives saved from avoided fuel tank explosions and post- crash fires do not meet the test of cost-effectiveness.

The Working Group's conclusion is based on a projection of future fuel tank explosions, and the effect of various mitigating actions. Consider some of the key assumptions:

For all of these reasons, the Working Group concluded that after "intensive efforts" it "could not devise a practical, timely and cost-effective method of proposing a fuel tank inerting design concept as a viable solution..." And, since it could not devise a cost-effective technology, the working group further conceded that it could not satisfy the tasking from its FAA master to submit proposed regulatory language mandating inerting for the fuel tanks of transport-category aircraft.

Lost in all this fatalistic heavy breathing was the Working Group's own calculations that inerting could be achieved for about 23-36 cents per ticket.

Not quite ignored were the results in the FAA's flight tests in the early 1970's of a prototype liquid nitrogen inerting system (see ASW, May 14). Some three pages of the Working Group's 600-page report were devoted to liquid nitrogen concept. The FAA Technical Center's August 1972 report (No. FAA-RD-72-53) of the installed prototype system and flight tests concluded:

"The liquid nitrogen inerting system is effective in maintaining a mixture in the fuel system vents and tank vapor spaces having a volumetric oxygen concentration of less than 8 percent under all normal and emergency flight conditions and without producing excessive tank pressure differentials."

At a concentration of eight percent oxygen (well below the 21% oxygen concentration in ambient air) the vapors in the ullage space are considered inerted.

The Working Group assumed that a liquid nitrogen inerting system would add some 1,356 pounds to the weight of a medium-size airplane. That is roughly 700 pounds more than the 643-lb. weight of the installed and charged-with-nitrogen system on the DC-9 that the FAA successfully flight tested nearly three decades ago.

Bottom line, the FTIHWG reduced the frequency of fuel tank explosions using the assumption that the new SFAR will prevent 75 percent of the anticipated explosions. With that one overarching assumption, the benefit side of the equation was reduced considerably. The accident frequency was extended from an average of one fuel tank explosion every 4.5 years to over 14 years.

Meanwhile, the FAA plans to soon begin ground and flight tests of a B747SP it purchased and instrumented for the specific purpose of further evaluating various inerting stratagems. If the sweeping assumptions behind the cost-benefit calculations prevail to kill the deployment of inerting technology, the FAA is about to expend considerable sums of money flight testing inerting technology deemed too expensive to deploy for the lives it could save.

The counter to this dead-end scenario is another - the industry could be just one more fuel tank explosion away from having to ignore cost-benefit calculations and deploy inerting technology anyway. Sources maintain all it would take is one airplane's center wing tank to explode on the tarmac on a hot summer day at a busy airport like New York's LaGuardia. With the airplanes parked close to one another as they are at LaGuardia, a single explosion could destroy airplanes parked alongside. Imagine the scene: a blackened spot on the concrete where the exploded airplane was parked, the hollow remains of its nose and tail at either end, its broken wings lying on the concrete. Adjacent airplanes showing evidence of fire and shrapnel damage. The windows in the concourse blown out. Fire trucks, ambulances and emergency vehicles surrounding the grim scene, their red lights flashing. The stark specter of destruction played endlessly on national television.

In this eventuality, the cost-benefit calculations that deemed inerting not worth the trouble, based on the illusory hope of finding "unknown" ignition sources, might turn out to be more of an embarrassing albatross around the necks of FAA and industry officials than a mathematical security blanket justifying inaction. The cost-per-ticket estimates for inerting, even if doubled or tripled to maybe $1 and change, might well add to the public outrage.

It may be useful to remember that the public perception of air safety is not shaped by accident rates but by events. One high-profile event can break a rulemaking deadlock. Recall the 1996 fatal crash of a ValuJet DC-9 into the Florida Everglades. Overnight, the price tag for cargo hold fire detection and suppression, previously deemed cost- ineffective at $300 million, was no longer prohibitive. The FAA ordered the industry to install this protection throughout the fleet. Even at the $2.7 million statistical value of a life, this one crash (110 people @ $2.7 million each + DC-9 worth about $2 million) was well over $300 million. Further, the FAA prohibited carriers from carrying oxygen canisters in aircraft belly holds. No cost-benefit was offered to justify this decision - it was based on the overarching need to eliminate a known hazard. The Safety Board concluded that ignited canisters started the fire that doomed the ValuJet DC-9.

Other cases reveal that the FAA does not apply cost-benefit when safety-of-life issues are involved. For example, the agency has ordered the wholesale replacement of metalized Mylar thermal acoustic insulation blanketing in the entire transport-category fleet of Douglas-built aircraft. There is no indication that this material has been involved as the principal cause of a crash and of loss of life, yet the program proceeds as a preventive measure.

And yet, when it comes to fuel tank inerting, where vapors have exploded, loss of life is almost always involved, even when the airplane is on the ground.

Dr. Bernard Loeb, recently retired NTSB head of aircraft accident investigations, argues that debating a safety initiative on the merits of cost-benefit is the wrong battleground. Even if the presumed effectiveness of the SFAR were reduced from 75 percent to 10 percent, inerting would not meet the cost-benefit test the way the analysis has been constructed. "Is this what should be driving the decision?" he asks.

Loeb asserts that placing heat-generating air conditioning packs directly under center wing tanks loaded with petroleum products (jet fuel) represents a flawed design concept. The mute evidence of such is provided by the grim toll exacted by explosions of unventilated, heated center wing tanks over the years. When it comes to remediating a flawed design concept, which is the real problem at hand, Loeb believes, the straightjacket of cost-benefit should not apply.

Security cost-benefit

The second case study deals with what the Federal Aviation Administration (FAA) calls the "cost of a catastrophic terrorist act." This case illustrates, too, how the benefit can be arbitrarily reduced, and how the cost figures are manipulated.

The calculation of the security investment is contained in two final rules published July 11 in the Federal Register. Some 16 years in the making, the new aviation security regulations take effect November 14, 2001. The new security rules represent the most significant changes to aviation security to be published by the FAA in two decades. They are, respectively, Part 107 of the Federal Aviation Regulations dealing with airport security, and Part 108 dealing with aircraft operator security. These documents, each more than 100 pages in length, contain a cost-benefit justification, the presentation of which provides perhaps the most detailed and publicly-available discussion of the terrorist threat to aviation.

We focus on the more detailed cost-benefit presentation in the Part 108 document. It cites an increasing threat to U.S. aviation from both international and from domestic terrorists. The document cites the 1994 plot conceived by Ramzi Yousef to bomb up to 12 U.S. airliners. The plot was uncovered by chance (not by heightened aviation security) and two of the five co-conspirators remain at large.

From this worst-case, real-world threat of an attack on a dozen U.S. airliners, the FAA's cost-benefit is based on a much-reduced hypothetical loss. One airplane, not 12. A fairly old B737, valued at some $16.5 million (far less than the purchase price of a new airplane); and one not fully loaded, but with only 73 of the 113 seats filled with passengers. This dramatic paring is equivalent to the slice made by the SFAR in the fuel tank inerting case above. Just as the SFAR stripped away most of the "need" for inerting, the assumption of one instead of 12 terrorist bombings dramatically reduced the scope of the security program to counter it that would still meet the test of cost-effectiveness.

At the $2.7 million statistical value of a life for 73 passengers, plus 2 pilots and three flight attendants aboard the FAA's representational B737, the value of the lives lost was placed at $210 million. The cost of other property damage, cost of investigation, and of legal fees, brought the total cost of one successful bombing attack to $272 million in current dollars, and to about $191 million in discounted dollars over a 10-year period. Thus, while the security team assumed the cost of an accident at $272 million, the fuel tank inerting group placed the cost of an accident at some $400 million. Even the hypotheticals are not consistent.

Moreover, this $272 million cost bears no relationship to real-world experience. Recall that the last successful bombing of a U.S. airliner was Pan Am Flight 103 in 1988, a B747 widebody with 270 passengers and crew aboard. According to sources, the destroyed airplane had a book value of $97 million, and liability settlements for the deceased ultimately totaled some $500 million. The cost of lost business stemming from sanctions against Libya, amounting to billions of dollars, might also be considered.

The FAA estimated the cost of its Part 107 airport and Part 108 aircraft operator security programs at $131 million in 1998 dollars, and at $104 million in discounted dollars. In both cases, in current dollars and discounted dollars, the costs were less than the cost of a bombed airplane. As such, the security programs were deemed cost-effective.

Twelve airplanes bombed out of the sky at a quarter-billion dollar price apiece would present a cost-effectiveness threshold of some $3 billion. At a cost of $400 million for each of a dozen bombed airplanes, a security program costing nearly $5 billion would still meet the test of cost-effectiveness.

One security expert said that if the threat is growing, as somberly noted in the FAA's rulings, a security program of $131 million might represent a totally inadequate response. Reducing the consequences neatly reduces the expenditures.

Which comes to the second part of the security saga. The Part 107 and Part 108 rulings are to be followed by regulations dealing with checked baggage security and the screening of security companies. The two extant and the two coming rulings, four overall, are estimated to involve a total discounted price of $2.3 billion. How to make that much greater dollar figure cost-effective? To justify this larger program, the FAA increased the analytical consequences to justify the greater expenditure. This was done by recognized that many passengers would not fly after the bombing of an airliner (an aspect ignored in the fuel tank inerting case, further illustrating the selective use of numbers).

By considering the potential losses to the market, the cost-effectiveness of security requirements could be based on the number of trips not lost by prevented explosions. In response to an ASW query, the FAA explained: "Since the cost of two explosions exceeds the cost of one explosion, the number of trips avoided for benefits to exceed costs drops. So, for 1 explosion, 16.3 million trips X $130 (per ticket) + $191 million (cost of one airplane bombed) = $2.31 billion, enough to exceed the cost of the 4 rules. For 2 explosions, 14.8 million trips X $130 + 2X $191 million = $2.31 billion, also enough to exceed the costs of the 4 rules."

Got it? In the real world, it seems likely that more people would be discouraged from flying if two airplanes were bombed out of the sky than one. But in the cost- benefit calculations, saving twice as many people from death means fewer lost trips have to be recovered in order for the benefits to remain below the $2.31 billion cost of the four rules.

Whether one starts with cost or benefit, the arbitrariness of the process is plainly evident. One could assume a threat ("cost") against 12 aircraft to justify a greater investment in security. Or, one could manipulate the number of people not discouraged from flying (the "benefit") by preventing one or more bombing attacks, although that number drops as the "benefit" increases by avoiding more bombings. To make the sums add properly, officials must wade into a metaphysical swamp.

Not included in the cost-benefit discussion is the impact of positive passenger bag match, or PPBM. This absence is most probably due to the fact that PPBM is not part of the regulatory mix, although some security experts argue that this is the single most effective step that could be taken to improve security. The cost of PPBM is estimated at some 18- 45 cents per ticket (see ASW, June 18). Yet, despite the reference in the final Part 107 ruling to the need for integrated and redundant security programs, PPBM was not mentioned.

No matter. The $2.3 billion cost of the four programs over ten years, at 600 million passengers per year, comes to less than 40 cents per ticket. In other words, the cost of these programs plus PPBM sums to less than $1 per ticket.

In this light, where passengers would probably agree heartily that the cost of preventing an airplane bombing is worth at least $1 per ticket, the cost-benefit calculation seems more like an arcane exercise in medieval scholasticism.

To be sure, any cost-benefit analysis for the threat of terrorism inevitably is going to be a speculative venture. By parsing the threat from 12 airplanes to one, the FAA may have made its speculative situation worse (i.e., estimate the threat on a least-case rather than a worst-case basis).

Apparently, cost-benefit is not used to justify expenditures for other security initiatives. For example, the 1997 White House Commission on Aviation Safety & Security (a.k.a., the "Gore Commission," so named after its chairman, then Vice President Al Gore) urged the deployment of explosives detection systems (EDS). In the four years since, Fiscal 1997-2000, the government spent more than $357 million for this equipment. An FAA official said no cost-benefit was done, cryptically adding the words "per se." At any rate, the official cited the Gore Commission's pronouncement that the federal government should consider aviation security "a national security issue and provide substantial funding for capital improvements."

One of the reasons for this approach may be recognition of the political costs. If another Pan Am 103-type bombing were to kill 200-300 passengers over American skies, the public outcry over the porous security that left an opening for such an attack would severely damage the credibility of the FAA and of the industry's security programs. Not only are cost-benefit calculations reduced almost to irrelevance on a per-ticket basis, the cost-benefit calculations are completely overshadowed by the political and institutional costs of failure.

Not surprisingly, the FAA was rather evasive - but at the same time commendably frank - about the trade-off. The FAA was asked at what point does a program have to meet the standard of cost-effectiveness? For example, if the Part 107 and Part 108 costs exceeded the $191 million discounted price of a single bombed airliner by one cent, would the program proceed? What about a security program costing $10 million in excess of the $191 million "benefit" of one avoided explosion? The FAA responded that it does not use a single criterion: "There are often unquantifiable costs and benefits, including political factors, which also are considered by FAA management."

Do the right thing

Quite so. The political and institutional costs, although virtually impossible to quantify in dollars and cents, can take on a much greater importance than the cost-benefit calculations.

A few summarizing observations may be in order. First, cost-benefit does not appear to be applied consistently, as evidenced by the millions of dollars spent on the purchase and deployment of explosive detection systems (EDS). And, to be sure, activities such as airworthiness directives issued to uphold current safety standards can involve costs far in excess of programs that must first pass the cost-benefit hurdle without tripping. In other cases, the FAA has mandated safety improvements without so much as a nod to cost- benefit.

Second, cost-effectiveness does not apply when it comes to protecting military personnel. The AH-64 Apache attack helicopter and the F-22 Raptor fighter both feature on board inert gas generating systems. Readers with longer memories may recall the dramatic and costly redesign of the Bradley infantry fighting vehicle after life-fire tests revealed its catastrophic vulnerability to enemy fire. Fuel and ammunition stowed inside the vehicle was repositioned in the so-called "high survivability" Bradley that saw its successful combat debut in the 1991 Persian Gulf War.

Third, the cost-benefit process has the appearance of an intellectually tortured tool used to justify desired outcomes.

Fourth, casting the deliberations in terms of cost-per-ticket may more appropriately put the focus on who really pays for safety and security - the passenger. As is often said, all costs ultimately are passed along and borne by the passengers.

Fifth, the utility of cost-benefit calculations should be recognized. There is an aphorism that says, "The purpose of analysis is not to produce answers, but insights." That being said, Dr. Loeb maintains these amoral analyses should not be the constraining consideration when it comes to decisions about safety.

Sixth, more flexibility might represent a more enlightened approach. When it comes to small businesses, the Part 107 and Part 108 rulings mention the need for regulatory flexibility. These documents go into precise detail about the impact of the security rules on small operators (e.g., $629 for each of 172 small aircraft companies). One source observed that families could be likened to small businesses, since the emotional and economic losses from an air crash can be as devastating to a family as bankruptcy can be to a small business. By this reasoning, a certain flexibility is warranted in the application of cost-benefit. Families, this source said, are not "statistical road-kill."

Moreover, to recall from the final 1997 report of the Gore Commission, cost-benefit should not be "dispositive" in matters of aviation safety and security. And, finally, the record is replete with examples where, in issues involving safety of life, cost-benefit was ignored outright. There is a big difference, one might say, between making sure things look right, and doing the right thing.

Cost of a Domestic Class I Explosion
Total Cost
$2.7 mil. each
$210 mil.
$16.5 mil.
$16.5 mil.
$12.5 mil.
$12.5 mil.
$28.6 mil.
$28.6 mil.
Legal Fees
$3.5 mil.
$3.5 mil.

$271.8 mil.
Total Discounted

$190.9 mil.

The Cost Effectiveness of Improved Security
Cost: Part 107 & 108 security rules
$131.3 mil.
$104.1 mil
Benefit: 1 airplane not bombed
$271.2 mil.
$190.9 mil.

'The Regulatory Philosophy'

The requirement for cost-benefit, as contained in Executive Order 12866 (extracts):


"Each agency shall assess both the costs and the benefits of the intended regulation and, recognizing that some costs and benefits are difficult to quantify, propose or adopt a regulation only upon a reasoned determination that the benefits of the intended regulation justify its costs."

"Each agency shall base its decisions on the best reasonably obtainable scientific, technical, economic, and other information concerning the need for, and consequences of, the intended regulation."

" 'Regulatory action' means any substantive action by an agency..."

" 'Significant regulatory action' means any regulatory action that is likely to result in a final rule that may: Have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety..."

Signed, William J. Clinton, The White House, September 30, 1993



Premature Deaths Save Money

Cost-benefit as public relations fiasco Public Finance Balance of Smoking in the Czech Republic (Extracts):


"The objective was to determine whether costs imposed on public finance by smokers are offset by tobacco-related tax contributions and external positive effects of smoking."

"The results of the study show that the total public finance balance of smoking in the Czech Republic in 1999 was positive.... Our principal finding is that the negative financial effects of smoking (such as increased health care costs) are more than offset by positive effects (such as excise tax and VAT [value added tax] collected on tobacco products."

"Indirect positive effects include savings in public health-care costs and state pensions due to early mortality of smokers, and savings on public costs related to the support of the elderly."

"This estimate is based on...the following assumptions:

Source: American Legacy Foundation. The full report may be viewed at

'Thousands of passengers would have been killed'


The FAA's threat assessment:

"Investigation into the February 1993 attack on the World Trade Center (WTC) uncovered a foreign terrorist threat in the United States that is more serious than previously known. The WTC investigation disclosed that Ramzi Yousef had arrived in the U.S. in September 1992 and had presented himself to immigration officials as an Iraqi dissident, seeking asylum. Yousef and a group of radicals in the U.S. then spent the next 5 months planning the bombing the the WTC...Yousef returned to Pakistan on the evening of February 26, 1993, the same day that the WTC bombing took place. Yousef traveled to the Philippines in early 1994 and...conceived a plan to bomb as many as 12 U.S. airliners flying between East Asian cities and the U.S.

"Yousef and co-conspirators Abdul Murad and Wali Khan tested the type of explosive devices to be used in the aircraft bombings and demonstrated the group's ability to assemble such a device in a public place, in the December 1994 bombing of a Manila theater. Later the same month, the capability to get an explosive device past airport screening procedures and detonate it aboard an aircraft also was successfully tested, when a bomb was placed by Yousef aboard the first leg of Philippine Airlines Flight 424 from Manila to Tokyo. The device detonated during the second leg of the flight, after Yousef had deplaned at an intermediate stop in the Philippine city of Cebu.

"Preparations for executing the plan were progressing rapidly. However, the airliner-bombing plot was discovered in January 1995 by chance after a fire led Philippine police to the Manila apartment where the explosive devices were being assembled. Homemade explosives, batteries, timers, electronic components, and a notebook full of instructions for building bombs were discovered. Subsequent investigations of computer files taken from the apartment revealed the plan, in which 5 terrorists were to have placed explosive devices aboard United, Northwest and Delta airline flights. In each case, a similar technique was to be used. A terrorist would fly the first leg of a flight out of a city in East Asia, planting the device aboard the aircraft and then deplane at an intermediate stop. The explosive device would then destroy the aircraft, continuing on a subsequent leg of the flight to the U.S. It is likely that thousands of passengers would have been killed if the plot had been successfully carried out.

"Yousef, Murad and Khan were arrested and convicted in the bombing of Philippine Airlines Flight 424 and in the conspiracy to bomb U.S. airliners. Yousef was sentenced to life imprisonment for his role in the Manila plot, while the two other co-conspirators have been convicted.... However, there are continuing concerns about the possibility that other conspirators remain at large. The airline-bombing plot, as described in the files of Yousef's laptop computer, would have had 5 participants. This suggests that, while Yousef, Murad, and Khan are in custody, there may be others at large with the knowledge and skills necessary to carry out similar plots against civil aviation."

Source: FAA, Part 108


News Briefs





NTSB Accident And Incident Investigations

7/17 Oak Creek, Wisc. Cessna 310R N1448Z Central Wisconsin Crashed during approach. IMC/N 1 - Fatal CHIO1FA218 Apparent descent below prescribed altitude during instrument approach for reason(s) not yet determined.
7/25 Detroit, Mich. Douglas DC-9-50 N780C Northwest Airlines, Inc. Turbulence encounter during descent. VMC/D 1 - (possibly serious) Other numbers not reported. CHIO1LA245 Passenger was in lavatory at the time. Possibly did not heed alert if issued by flight crew.
1 U.S. air carrier incidents or accidents, or other accidents involving serious or fatal injuries, investigated by the National Transportation Safety Board. 2DISCLAIMER: The information obtained from the NTSB is preliminary, possibly incomplete, and may be supplemented by new findings of fact as the inquiry progresses. These assessments, based on a reading of initial reports, are not intended to assert probable cause or liability, but rather are intended to provide insight pending publication of a final report of investigation. 3 Visual meteorological conditions. 4 Instrument meteorological conditions. 5 D=Day; N=Night. -Data, exclusive of Rudolf Kapustin's preliminary analysis, compiled from National Transportation Safety Board documents.