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19 The second component of a comprehensive FOD management program involves detection. Clearly, if upon inspection there is no debris, then no FOD will be detected, thus eliminating this step. If, however, debris exists on the AOA, it should be detected. Indeed, the most critical aspect of any FOD manage- ment program is the actual detection of debris. If FOD that exists is not detected by the airport employee, there will be no opportunity for the subsequent removal or documentation of the debris. Time is perhaps the most crucial aspect of the detection phase of the FOD management program. As seen in the case of the Concorde accident, a piece of FOD can become present on an airportâs surface at any time, resulting in a seri- ous accident if not promptly detected and removed. Therefore, it may be insufficient to simply inspect for FOD at certain times of the day. A continuous monitoring system does much to assist the airport in detecting FOD at any point in the day. Even so, several types of inspections exist and, ultimately, the most important objective is the detection of FOD, whether this occurs manually through regular inspections or with automa- tion through continuous monitoring equipment. Even considering personnel and training costs, manual detection of FOD may be a less expensive detection method than other options. Indeed, manual detection is an impor- tant part of any FOD management program, whether or not that program includes the use of FOD detection technology or equipment. Effective manual detection of FOD relies heavily on personnel employed at the airport to regularly monitor their surroundings to detect the presence of debris. This includes personnel performing the daily self-inspection, monitoring of construction activities, working on the ter- minal or ramps, attending gates, handling baggage, fueling aircraft, piloting aircraft, and controlling air traffic, as well as anyone who works on the AOA. Most commonly, a manual inspection for FOD is carried out by an airport employee (such as an operations employee) as part of a daily self-inspection. As discussed in chapter two, such inspections involve multiple passes of runways and taxiways, usually in a vehicle, with the employee visually inspecting for, and hopefully detecting, any existing debris. CURRENT EQUIPMENT AND TECHNOLOGY AVAILABLE FOR DETECTION Detection Equipment and Technology In addition to manual methods, various forms of technology are currently available to aid the airport operator in detecting FOD; devices that can make the detection of debris much easier for airport operators. Most FOD technology currently being promoted to airports is focused on the detection of FOD. This focus on detection is well-deserved, because with only one or two manual inspections per day at many airports there is considerable opportunity to enhance the ability to detect FOD. Many of the manufacturers of detection technol- ogy promote a 95% or better detection rate under all weather conditions with 24/7 operation. This track record is not pos- sible with a manual inspection and detection system. In addition, some of the FOD detection technology on the market serves multiple purposes. For instance, modern sen- sors may detect wildlife. FOD detection systems may also to some degree provide surveillance of the AOA. In essence, FOD detection technology is intrusion technology, alerting personnel to foreign objects (including wildlife and possibly personnel) on the AOA. However, the application of these systems for these additional uses has not been approved by the FAA. Therefore, more research will be needed in this area in the future. In an effort to inform airport operators of the available systems for FOD detection, the FAA has developed AC 150/5220-24, Foreign Object Debris Detection Equipment. This AC summarizes the major types of FOD detection sys- tems (FAA 2009a). As seen in Table 2, these include both manual and automated systems. Detection Continuum In using these systems identified by the FAA, and based on findings from this synthesis, a continuum was developed show- ing the degree of automation present in the various types of FOD detection technology and equipment. It can be noted that the continuum is driven by the differing capabilities of the tech- nology (see Figure 9). Manual Foreign Object Debris Detection Just as with the inspection stage, the FOD detection stage also has a manual option. Whether proactively, involving an airport employee driving a vehicle on the airfield and detecting FOD during a self-inspection, or reactively, with FOD first being detected by a pilot or ATC, the manual detection of FOD has been in use at airports for decades. Although the human eye may not detect very small debris or have difficulty discerning CHAPTER THREE DETECTION
20 ytilibapaCselpicnirPnoitceteDmetsyS Human/Visual Fundamental baseline for the performance of FOD detection systems. Human observation provides detection and human judgment provides the hazard assessment capability to assure safety. Supports regularly scheduled, periodic condition, and special inspections Radar Uses radio transmission data as the primary means to detect FOD on runways and AOA surfaces. Fixed systems support continuous surveillance; mobile systems supplement human/visual inspections Electro-optical Uses video technology and image processing data as the primary means to detect FOD on runways and AOA surfaces. Supports continuous surveillance Hybrid Uses a combination of radar and electro-optical data as the primary means to detect FOD on runways and AOA surfaces. Supports continuous surveillance Adapted from AC 150/5220-24 (FAA 2009a). FIGURE 9 Continuum of technology and equipment available for detection. TABLE 2 SUMMARY OF FOD DETECTION SYSTEMS debris during reduced visibility or minimal contrast condi- tions, manual detection can be effective with properly trained employees having a keen eye for foreign objects on the air- field. Furthermore, McCreary (2010) presents findings that indicate that there is little debris below a size of 0.8 in. and weight of 0.07 ounces, or 2 cm/2 gram, typically present. Supplemental Foreign Object Debris Detection Located between manual and automated detection on the con- tinuum, technology-assisted manual detection can be used to supplement human ability in detecting FOD. Typically in the form of cameras, the effectiveness of inspections can be enhanced by supplementing the visual observation con- ducted by airport personnel. A camera can be mounted on an inspection vehicle or at a fixed location (typically a termi- nal building). A camera mounted on an inspection vehicle may be a Forward Looking Infrared to enable more accurate detec- tion of FOD during nighttime and low visibility conditions. Fixed location cameras are manually controlled and may be used to scan the airfield. Cameras are oftentimes most effec- tive once FOD has been reported, as they allow the opera- tor to zoom in on the FOD to verify its location and type, providing additional information to personnel responding to the FOD. Automated Foreign Object Debris Detection Automated FOD detection systems can be more expensive than manual methods, but may also prove more effective. In
21 the report, Runway Safety, Insight SRI, a provider of auto- mated detection technology, explains: . . . Properly applied, the technologies of automated runway scan- ning (ARS) represent a major opportunity for both airlines and airports. The opportunity is not only to improve safety, but to improve the bottom line to the tune of millions of dollars. Curi- ously, it is an opportunity that has been consistently and expen- sively overlooked for almost a decade (McCreary 2010, p. 23). Specifically, data from Vancouver International Airport (the first airport in the world to adopt automated detection technology) show that FOD is detected on the runways, on average, once every two days. This, according to McCreary (2010), is a sixtyfold improvement over airports relying only on visual inspections, where debris are typically found once every two months. Therefore, depending on the size of the airport, the degree of the debris problem, and the resources available, automated FOD detection systems may be a valid option. Rather than being used in isolation, automated systems, such as those offering continuous surveillance, are designed to augment manual detection strategies, such as periodic visual inspections. This is an important supplement, as inspection personnel may only know the status of FOD on a runway 0.5% of the time when solely relying on manual detection of FOD (B. Patterson, personal communication, 2010). It can be noted, however, that these systems are automated, rather than automatic. Although many of these automated systems are continuous, the systems do require human interface to inter- pret system output. Although some in the industry (such as McCreary) advo- cate the adoption of automated FOD detection technologies by airports, the technology remains relatively new and is not currently widely utilized. For instance, in 2005 the first auto- mated runway scanning system was installed at Vancouver International Airport in Canada. Four years later, in 2009, the FAA approved the four technologies then on the market for Airport Improvement Program fund eligibility. By 2010, however, only six airports throughout the world had adopted automated scanning systems (McCreary 2010). As explained by McCreary (2010, p. 31), âNeither the regulators, the air- lines, nor the airports have collected the statistics required to make a strong case for automated scanning.â Radar The first type of automated system utilizes radar, typically in the form of millimeter-wave radar. This technology uses extremely high frequency in the range of 30 to 300 gigahertz (GHz). This band has a wavelength of ten to one millimeter, giving it the name millimeter band or millimeter wave. Cur- rently, there are both fixed and mobile systems that incorpo- rate millimeter-wave radar. A mobile system currently on the market contains radar that incorporates a 78â81 GHz sensor mounted on a reciprocating platform on top of the vehicle that allows the scanning of a field of approximately 80 degrees in front of the vehicle. The antenna tilt is fixed in relation to the vehicle, scanning at the rate of 30 scans per minute and pro- viding a detection distance in front of the vehicle of approx- imately 650 ft with a detection âcellâ of approximately one square yard. The system also features a high-quality GPS that can be calibrated to reach near differential GPS accuracy and a photographic system that is coordinated with the system software to provide images of detected FOD (âFOD Finderâ n.d.; Patterson 2008). A fixed system currently on the market uses a combina- tion of sensor technology and advanced digital signal pro- cessing to automate FOD detection. Millimeter-wave radar is used to give uninterrupted coverage of the runway, while object identification is enabled by a powerful day and night camera system cued onto the object automatically. The radar is accurate at distances of up to 0.6 mile. With this radar scan- ning technology, an entire runway can be covered by just two to three units (Patterson 2008). Indirect Benefits: â¢ Allow airport to actively control their risk profile (same risk applied to all flights) â¢ Fewer delays means lower carbon emissions â¢ Reduce total manpower (over time) as systems roll out. Longer Term Benefits â¢ Flexible decision making by tower and airport â¢ New methods to reduce delays and minimize inefficiencies â¢ Add new network capacity â¢ Preserve existing airport runway capacity â¢ Reduce operational variability â¢ Sustain operational tempo â¢ Low visibility operations â¢ Add new airport runway capacity â¢ Reduce runway closure times â¢ Improve punctuality and time of entry into the en route system â¢ Allows for an international, standardized approach to safety and hazard management â¢ Major improvements in safety data recording and risk management. Source: McCreary 2010, p. 207 Benefits of Automated FOD Detection Direct Benefits: â¢ Detect, find, and identify FOD or other runway hazards â¢ Improve operational safety â¢ Reduce airline operating costs â¢ Reduce airport operating costs â¢ Provide uniform risk exposure for all movements.
Electro-optical Sensors Yet another type of technology utilizes electro-optical sensors. One system currently on the market using this technology fea- tures self-calibrating cameras, automated scene analysis, and configurable scan resolution for different object sizes. These remotely placed electro-optical sensors provide continuous surveillance of the runway surface on a 24/7 basis. Objects can be detected at night without supplemental illumination, although because it is optical the detection capability of the system may be affected by certain types of weather (âIferretâ n.d.; Patterson 2008). Hybrid Some technology is considered hybrid in that it utilizes both radar and electro-optical sensors. One product currently on the market is promoted as âdual technology.â This product combines a millimeter-wave radar sensor and an optic sen- sor that scans a portion of the runway and analyzes the data locally to detect foreign objects. In cases of positive detection, the operator receives both an audio and visual alert. With multi- sensor deployment, an airportâs runway and taxiway surfaces can be scanned in as little as 30 s. Generally, the sensors that are collocated with runway edge lights are located on every or every other edge light, based on airport requirements (âFODetectâ n.d.; Patterson 2008). Decision Process Although airports may be hesitant to investigate automated FOD detection technology owing to the cost, it is prudent to consider how automated technology may improve an airportâs overall FOD detection capability. As explained by McCreary (2010, pp. 31â32), by comparing findings from automated detection systems and findings from visual runway inspections: Unassisted visual runway inspections may find better than 80% of the debris present at the time of inspection, but are in total no more than 3â4% effective in terms of finding and removing all items present on the runway throughout the operational day. This means that airports relying on visual inspections are in fact exposing their airline customers to a relatively high strike risk, and thus to higher operating costs than is otherwise necessary. In deciding which of the FOD detection systems to acquire, airports are encouraged to consider many different factors affecting the success of the system in their specific airport operating environment. The FAA, through AC 150/5220-24, encourages airport operators to consider the following factors (FAA 2009a): â¢ Number and type of aircraft operating, â¢ Number and size of surveillance areas, 22 â¢ Location of surveillance areas, â¢ Detection equipment precision and sensitivity, â¢ Detection equipment maintenance requirements, â¢ Airport climate, and â¢ Ability of personnel to respond to alerts and recover FOD from runway surfaces. These factors, when considered in light of the available resources, will guide airports in (1) deciding if an automated system is appropriate, and, if so, (2) which specific system to acquire. FOREIGN OBJECT DEBRIS RISK ASSESSMENT Immediately after FOD has been detected, a decision is made about how to handle it. This involves an assessment of risk, and takes place whether FOD has been detected manually or through automated means. In actual practice, risk assess- ment in a FOD management program is a two-part process. At the point of FOD detection, an instantaneous, and possi- bly subconscious, decision process is carried out by the indi- vidual detecting the debris in determining how to initially handle the FOD item. In simple terms, just as an individual decides whether to drive, walk, or take a taxi to work, the FOD inspector immediately makes several decisions, includ- ing how to move and dispose of the debris, whether certain areas of the AOA need to be closed for further removal or inspection, and how best to document the FOD. As men- tioned, in most instances, this form of a risk assessment hap- pens instantaneously, and the inspector may be unaware that a risk-based decision process has been carried out; nonethe- less, the process has taken place. With the Proposed Rule, Safety Management System for Certificated Airports, issued by the FAA in 2010, this process of risk assessment will likely be required at all certificated airports in the near future. Specifically, the proposal would require a certificate holder to establish a Safety Risk Man- agement process to identify hazards and their associated risks within the airportâs operations. Under a Safety Risk Man- agement (FAA 2010b), the airport would be required to: â¢ Identify safety hazards; â¢ Ensure that mitigations are implemented where appro- priate to maintain an acceptable level of safety; â¢ Provide for regular assessment of safety level achieved; â¢ Aim to make continuous improvement to the airportâs overall level of safety; and â¢ Establish and maintain a process for formally document- ing identified hazards, their associated analyses, and man- agementâs acceptance of the associated risks. A more in-depth discussion of risk assessment is presented in chapter five.
23 100% 28% 6% Manual Automated - mobile Automated - fixed 84% 59% 51% 49% 31% 4% Notify airport operator Close, or restrict activity in, affected areas Advise pilots Redirect traffic Letter of agreement with ATCT No formal procedures exist FIGURE 10 Systems in use to detect FOD. Note: Participants were asked to select all that apply. Thus, percentages do not total 100%. FIGURE 11 Procedures if FOD detected by others. Note: Participants were asked to select all that apply. Thus, percentages do not total 100%. CURRENT AIRPORT DETECTION PRACTICES Systems in Use When queried as to the type of systems in use to detect FOD at participating airports, 100% of respondents indicated they used a manual system, such as human or visual detection (Figure 10). Clearly, this is the most common method identi- fied by respondents for detecting FOD at airports. At Part 139 airports, daily airfield inspections are required, and during these inspections airport personnel also inspect for, and hope- fully detect, any FOD on the airfield. However, some air- ports have also adopted additional systems to detect FOD. Specifically, 6% of participants use a fixed system to support continuous surveillance. Just over 14% use a mobile system to support periodic surveillance. Procedures in Place for Foreign Object Debris Detected by Others Although it remains the airport operatorâs responsibility to properly detect and remove FOD, oftentimes, owing to the nature of airport operations and the timing of FOD inspec- tions, debris may be detected by someone other than the air- port operator, such as a pilot or the ATC. If debris were detected by someone other than the airport operator, partici- pants were queried about the procedures they had in place. As can be seen in Figure 11, 31% of participating airports
actually have a Letter of Agreement in place with the ATC for these instances. The vast majority (84%) expect the ATC to notify the airport operator if FOD is discovered. At that time the airport would dispatch personnel to immediately remove the debris. Approximately half of the participating airports (1) close, or restrict activity in, affected areas; (2) redirect traffic; and (3) advise pilots. In essence, by ensuring that the airport operator is advised as soon as FOD is discovered, air- craft can be prevented from operating in an area where debris are present until it is properly removed. Investigation into Detection Technology and Equipment In an effort to determine the degree of airport interest in tech- nology and equipment for the detection of FOD, partici- pants were asked if they had investigated the various types of technology and equipment available for such detection. Of the airports participating in the synthesis survey, 41% answered in the negative, whereas 33% indicated they had indeed investigated the various options available. Addition- ally, 27% of respondents had âsomewhatâ investigated the options available. Airports Without Technology and Equipment in Use for Detecting Foreign Object Debris Airports were also asked if they currently use any technology or equipment (such as radar or electro-optical sensors), in addition to the manual system in use, for detecting FOD. The vast majority (96%) answered no. When asked if they had plans to acquire, in the next 24 months, any technology or equipment for detecting FOD, 65% of these same airports indicated they had no plans. However, 27% were unsure, which 24 might indicate some degree of consideration of the various types of technology and equipment on the market today for detecting FOD. Airports with Technology and Equipment in Use for Detecting Foreign Object Debris Only two participating airports (4% of respondents) indicated they currently use some sort of technology or equipment for detecting FOD. Both airports utilize systems combining mil- limetric wave radar with an optical zoom camera system for automated runway FOD detection, location, and alerting. One airport uses a tower-based system, the other a ground-based system. Likely, these results are indicative of airports nation- wide; with the vast majority not yet having acquired advanced technology for detecting debris (McCreary 2010). Vancouver International Airport, in early 2006, became the first airport in the world to acquire the Tarsier FOD radar detection system from QinetiQ. Airport officials acquired the system with the hope of improving airport safety by accu- rately detecting FOD between self-inspections. Four Tarsier radar units were installed at Vancouver, one at each end of the northâsouth parallel runways. A display unit, installed in the operations center, provides the airport operations team with an all-weather, 24/7 runway picture. By providing staff with coordinates of FOD, and by entering these coordinates into a GPS navigation system, operations personnel are able to quickly and accurately locate and retrieve the debris. Source: http://www.defensefile.com/Customisation/News/Civil_ Airlines_Airports_and_Services/Runway_Security_and_Safety/ QinetiQ_-_Tarsier_FOD_radar_detection_system.asp