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32 for arrestors with a manufacturer contract was 3.0, while the their physical condition over time. Representatives from the weighted average maintenance for arrestors without a manu- FAA indicated that such sensing methods may or may not be facturer contract (maintenance was performed either by local feasible for the future due to several technical complications. contractors or airport personnel) was 2.7. Laboratory tests have underscored the difficulties associated In addition to providing numerical responses, airport oper- with this concept. ators provided verbal commentary on the maintenance require- Costs for an EMAS appear to exceed the expectations of ments. When asked to describe the negative traits of their EMAS FAA Order 5200.9 with regard to the three main categories: systems, many cited maintenance problems. Their responses preparation, installation, and maintenance. While the survey are summarized as follows: included more airports than the original data set used to create Order 5200.9, it did not include all EMAS systems installed at Arrestor beds require continual maintenance and inspection, U.S. airports. It is possible that the average costs could shift which are both expensive and inconvenient; once the remaining airports were included. The durability of the arrestors is uncertain, and the effect of possible deterioration on performance is unknown; Airports with arrestors installed prior to 2003 mentioned 3.8. Perception of Active Arrestor that the top layer of the beds tended to deteriorate; and 3.8.1. Survey of U.S. Airport Operators The arrestor beds are susceptible to being damaged by airport operations vehicles. Airport operators were asked how comfortable they would be with installing a net-based or cable-based active arrestor When airport operators were asked about what changes for civil aircraft. The possible responses were not comfortable, should be made to the arrestor design, the durability was again low, moderate, and highly comfortable. The results are shown a significant concern. Comments pertaining to durability and in Figure 3-12. A full 86% of respondents were either not maintenance are summarized below: comfortable or had low comfort with use of an active arrestor for civil aircraft. None of the operators responded with "highly A means should be developed for assessing the arresting comfortable." capability of an installed arrestor; The inconvenience of maintaining the bed should be 3.8.2. Other Aviation Organizations decreased; Adherence of paint should be improved; and As part of the survey effort, 23 individuals, many repre- The method of taping and caulking to seal tops of bed senting pilot organizations, were contacted to provide input blocks could be improved. on the appropriateness of active arrestors for civil aircraft. Appendix B provides a list of the organizations contacted. It should be noted that the manufacturer has developed a These individuals were selected to provide insight into the second-generation top--colored plastic as opposed to the perspective of pilots and other aviation personnel. first-generation painted cement board--that it claims is more durable. Low 22% 3.7. Observations for Survey Regarding EMAS The survey respondents and site visit personnel had a variety of opinions, ideas, and desires regarding the current EMAS technology. Issues regarding maintenance varied due to differences in region, bed age, etc. With respect to the maintenance-related responses, it should be considered that Moderate 14% EMAS designs have been improved over time, and now use different environmental protection measures than in the past. Not Not all user responses reflected experience with the most Comfortable 64% recent version of available EMAS designs. Many respondents expressed a desire to incorporate inte- grated sensing technologies into the arrestor beds to monitor Figure 3-12. Level of comfort with active arrestor.