Problems of ensuring safety in civil aviation.
Aviation Week & Space Technology.- 1996 .— 145, No. 4 — P.23-27.
New Security Issues in Civil Aviation
The explosion of TWA Flight 800 of TRANS World Airlines on July 17, 1996 raised new security issues in civil aviation, as it recalled the crash of Pan Am03, the Oklahoma City bombing, and recent terrorist activities in Saudi Arabia.
One of the complex problems is related to the use of new generation technical means at airports for screening passengers and their baggage. Aviation security experts believe that such means, based on modern complex technologies, are already ready for use. But this may cause some opposition from the public, which is related to the operating principle of the new screening means. X-ray screening systems form images of the objects and subjects being screened. When a person is scanned with low-intensity X-rays, everything hidden under his clothes is reproduced on the monitor screen. Other systems based on the detection and analysis of chemical substances are associated with possible direct contact between the passenger and the operator or between the passenger and the sensor of the detection system.
The National Research Council's (NRC) report on the state of security in civil aviation called on the Federal Aviation Administration (FAA) to study and evaluate public reaction to the introduction of new airport screening systems as soon as possible and to find a compromise between the positive characteristics of the new systems and the public reaction to the introduction of these systems, which differ from the usual walk-through metal detectors.
The NRC report, released in June 1996, emphasized the need to consider the health and privacy implications of new systems and to balance these factors against the growing terrorist threat from plastic explosives and non-metallic weapons. The report called for more sophisticated screening technology for airline passengers even before the TWA 800 crash. The NRC believed that public opposition could be mitigated by offering passengers a choice between X-ray screening and hand searches. The latter would be more expensive for airlines and less effective. The NRC report strongly recommended that public opinion polls be conducted on all proposed screening methods to avoid wasteful implementation costs.
The report also recommended that preliminary estimates be made of the additional costs to airlines and airports associated with the increased space required to install the new systems, the necessary equipment, and the training of operators.
Determining public attitudes toward new screening systems is not an easy task, since the term «public» includes diverse groups. Although air travelers will be screened, the impact could extend to others, including family and friends leaving for the airport, airline crews, and airport and airline employees. The FAA must determine what public objections can be accommodated without disrupting normal operations.
Another problem with public opinion polling is that public attitudes toward the questions posed may change depending on the level of terrorist threat at the time of the poll. Preliminary data show that public opposition to screening systems that affect people's personal interests increases as the likelihood of terrorist criminality decreases. For example, in response to public opposition, American Science and Engineering's Body Search X-ray imaging screening system was adopted for Level 2 and Level 3 screening of only suspect passengers who might pose a potential threat, but not all passengers.
The NRC report recommends determining the level of terrorist threat at which the public can accept the use of X-ray systems to screen all air travelers, not just suspects. It also recommends adopting a program to educate the public about the benefits of new screening systems and the limitations of current screening systems. In particular, the public should be made aware of the safety of X-ray radiation levels for human health. It is especially important to emphasize that this radiation is safe for pregnant women and people with pacemakers. This information should be communicated in the form of posters posted at air passenger screening points.
The NRC report recommends that the following guidelines be followed in the routine use of screening systems:
— ensure that images on screen monitors are interpreted by operators of the same gender as the air travelers undergoing screening;
— position screening system monitors so that images on their screens are accessible only to screening system personnel;
— present to air travelers the need to choose an alternative screening method if they object to X-ray screening;
— mask individual sections of the image; — ensure that when suspicious objects are detected, their image remains on the monitor screen after a short inspection procedure;
— train operators to identify specific types of threats and locate them. This should minimize disruption to air travelers and limit intrusions into their personal interests. Proper training should also help operators more accurately define search areas and avoid accusations that they have exceeded their authority when searching for threatening objects. Under current regulations, air travelers and other persons on airport property are only permitted to search for items that pose a threat to aviation security (firearms, knives, and other metal weapons). Airlines do not have the authority to search for other illegal or suspicious items or substances, such as large quantities of drugs or cash;
— determine the time required to screen passengers in a realistic airport environment. The NRC report states that an ideal screening system should detect both metallic and non-metallic threats in 6 seconds or less. This time is critical when there is a large volume of inspection operations.
Airport security systems in the United States currently screen up to 1.5 million passengers and their baggage daily. Domestic airports typically use walk-through metal detectors to screen passengers and X-ray machines to screen their carry-on baggage.
An ideal screening system should also provide operators with enough information in a format that is easy to use so that they can make quick, accurate decisions when alarms are triggered. Accordingly, screening systems should have a high detection rate and a low false alarm rate.
With regard to new methods for detecting explosives based on trace amounts of the chemicals they contain, the NRC report recommends that contact sampling of secondary samples from objects that the passenger has touched or from parts of the body (such as hands) be preferred.
Because of the challenges airports and airlines face in adopting new screening systems, including operational efficiency and cost, the report recommends that the FAA pursue a policy of widespread adoption of advanced systems and provide full support and assistance to airports and airlines in this regard. It is noted that the benefits of such systems are not immediately obvious.
Before implementing new screening technology, it is necessary to obtain comprehensive information on its advantages over currently available screening systems.
Airports and airlines will look to reduce the cost of implementing new technologies, both through automation and by reducing the number of screening points and their staffing. The report cautions that caution is needed in this approach. First, it should be taken into account that the amount of equipment and personnel required for security systems varies significantly over time, making it difficult to determine the necessary costs. Relying solely on permanent screening facilities and the operators who service them to eliminate threats could lead to significant delays in screening passengers. Computer modeling can be used to address this issue. The FAA is already taking steps to encourage airports and airlines to use this approach.
If the number of screening system personnel is reduced, this may entail increased costs for training and coaching of operators. Automation of screening systems will require higher qualifications of operators, since they must perform more complex and difficult tasks. When developing new screening technologies, it is more efficient to include certain functions in the automated screening cycle than to train operators to perform them in already installed systems.
Therefore, the NRC report recommends that the implementation of new screening technologies be included in long-term plans for improving civil aviation security. In terms of improving the performance of screening system operators, it is recommended:
— develop methods for measuring the performance of operators of existing inspection systems;
— apply methods of ergonomics, selection, and training of inspection system operators;
— determine the optimal ratio of automatically performed functions and functions performed by operators in new inspection systems.
The report strongly condemns the unfair treatment of screening system operators. Their pay is often inconsistent with the working conditions of their work. For example, operators of hand luggage screening of air passengers are often required to identify rarely encountered search objects by weak features. However, increasing the pay of operators alone cannot solve all the personal problems associated with them. Their efficiency can only be improved by more careful selection of future operators whose personal qualities would be most compatible with the upcoming work. This compatibility requirement is strengthened as screening systems become more complex.
Weak links in a screening system affect its efficiency to no less an extent than insufficient qualifications of operators. Common shortcomings of screening systems include the following:
— the image on the monitor screen cannot provide the operator with sufficient information about the actual dimensions of the objects being screened; all items of baggage of different sizes are presented on the screen as items of approximately the same size;
— the monitor controls do not allow the operator to determine the shape of the items and their location code. As a result, the operator cannot work without accessing the control panel;
— data integration and image processing methods are not used to their full effectiveness to obtain images with sufficient clarity for their interpretation;
— the design of the equipment forces the operator to work in a position that is uncomfortable for viewing images.