Compilation of Noise Programs in Areas Outside DNL 65 (2009)

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14 This chapter presents results of the ACRP survey summariz- ing responses to questions on methods to minimize and abate aircraft noise, including noise abatement flight tracks, noise abatement operational procedures, and ground noise control. NOISE ABATEMENT FLIGHT TRACKS AND FLIGHT PROCEDURES Twenty-two of the surveyed airports (63%) have noise abate- ment flight tracks. Half (50%) reported that noise abatement flight tracks were developed to address noise both inside and outside DNL 65, and nearly 41% reported that the noise abate- ment tracks were developed primarily to address noise outside DNL 65. Further, all airports reported noise abatement flight procedures reduced noise and complaints outside DNL 65; 72% said noise abatement tracks were “very to moderately effective” in reducing noise and 62% said it was “very to mod- erately effective” in reducing community complaints. Figure 2 presents responses to the question, “Type of noise abatement track” (note there can be multiple responses). The majority of these airports (63%) use jet departure noise abate- ment flight tracks, whereas 51% use jet arrival flight tracks. More than 30% of the airports use propeller and helicopter arrival and departure flight tracks. Thirty-four percent of respondents (12) reported that they have received formal FAA approval for their noise abate- ment flight tracks; 11% reported they have received NEPA approval. Airports report that air traffic controllers implement the flight procedures as follows: 40% use vectoring, 29% spec- ify VOR radials with turns and distant measuring equipment altitude requirements, 20% use RNAV, 14% use a global posi- tioning system, and 20% cited other procedures but without air traffic control (ATC) assistance. Airports reported a similar use of operational noise abate- ment procedures (i.e., cockpit procedures) designed to mini- mize noise during different types of operations. As shown in Figure 3, more than half of respondents (54%) have some type of noise abatement departure procedure (NADP) or Interna- tional Civil Aviation Organization (ICAO) procedure; many also have jet arrival procedures such as CDA (40%), propeller departure procedures (43%), and propeller arrival procedures (37%); more than one-third (34%) reported helicopter depar- ture and arrival procedures. Airports typically communicate their noise abatement flight tracks and procedures to pilots in one of three ways: 37% use posters/hand-outs, 34% use Jeppesen inserts, and 29% use pilot briefings. FAA Standards are used by 17%, and 23% use other means to communicate flight procedures including air traffic controller instructions, tower instructions, airport websites, and the airport facility directory. Survey respondents reported that a range of noise metrics are used to evaluate noise abatement flight tracks and proce- dures including DNL, CNEL, Maximum A-weighted Sound Level (Lmax), Time Above, number of audible aircraft noise events, Sound Exposure Level (SEL) and Continuous Equiv- alent Sound Level (Leq). Respondents also reported a wide range of noise levels used to evaluate flight tracks among the various noise metrics. Some airports reported that no assess- ment was conducted. Responses to this question suggest that there is a need for better guidance in developing noise abate- ment flight tracks. The survey results suggest that airports do not have suffi- cient information on the implementation costs of noise abate- ment procedures, especially the costs to operators and the air traffic system. Eight airports reported that airline fuel costs are increased by implementing noise abatement flight proce- dures. The airports also commented that total aircraft opera- tors cost for implementation was between nothing and $750K annually. Specific responses included, “A bit extra time and fuel” and “Minimal.” FAA cost was reported as “Nothing” or “Unknown.” The challenges to implementing flight tracks are shown in Figure 4. The single greatest challenge that airports reported was communication with pilots (34%); other challenges to implementation included communication with ATC (29%), communication with the community (29%), increased flight time (26%), and increased fuel costs to airlines (20%). Airports reported a variety of navigation procedures to implement noise abatement flight tracks: the most common is radar vectoring (40%), followed by VOR–distant measuring equipment (29%), RNAV (20%), and Global Positioning Sys- tem (14%); three airports reported that the procedures were voluntary and had no ATC involvement. Finally, respondents reported that both noise abatement flight tracks (Figure 5) and procedures (Figure 6) are generally CHAPTER FOUR OPERATIONAL PROCEDURES

15 FIGURE 2 Types of noise abatement flight tracks at surveyed airports. FIGURE 3 Types of noise abatement procedures at surveyed airports.

16 FIGURE 4 Challenges to implementing noise abatement flight tracks at surveyed airports. FIGURE 5 Effectiveness of noise abatement flight tracks at surveyed airports. 0 5 10 15 20 25 Reducing noise Reducing complaints Number of Respondents Not at all effective Somewhat effective Moderately effective Very effective “moderately effective” or “very effective” at reducing noise over noise-sensitive communities outside DNL 65, but some- what less effective at reducing complaints outside DNL 65. Also, a higher percentage of respondents reported that flight tracks are “very effective” at reducing noise (36%) than report flight procedures as being “very effective” (19%). AIRCRAFT GROUND NOISE CONTROL Twenty-four of 35 airports (69%) reported some procedures to minimize noise from aircraft operations on the ground, such as taxi and pre-takeoff runups; of these, 38% said the procedures were primarily to address noise within DNL 65, 25% that the procedures were developed primarily to address noise outside DNL 65, and 38% that their procedures were developed to address noise issues both inside and outside DNL 65. The most common types of procedures are iden- tified in Figure 7; they include physical construction of blast fences (31%), ground runup enclosures (GRE) (11%), and noise barriers/berms (20%); as well as runup proce- dures (29%), pre-takeoff runup policies (23%), reverse thrust policies (14%); and simply moving the aircraft away from noise-sensitive communities (23%). Ground noise control procedures are implemented using formal rules and regulations (26%), informal means such as tower or air traffic controller coordination (14%), or both for- mal and informal means (31%). These procedures are com- municated to pilots by posters (43%), briefings (31%), and

FIGURE 7 Types of ground noise procedures at surveyed airports. 17 FIGURE 6 Effectiveness of noise abatement procedures at surveyed airports. 0 5 10 15 20 25 Reducing noise Reducing complaints Number of Respondents Not at all effective Somewhat effective Moderately effective Very effective FIGURE 8 Effectiveness of ground noise procedures at surveyed airports.

other means such as airport operations or maintenance brief- ings (40%). Respondents reported that the greatest implemen- tation challenges are communication with pilots (34%), com- munication with ground control (11%), and communication with the community (11%). Other implementation challenges reported included taxi time, fuel costs and emissions, and oper- ations staff enforcing curfew rules. 18 Airports were very aware of implementation costs for capi- tal expenditures such as GREs, but had little information on costs of other operational programs, and little information on costs to operators. The maximum reported airport cost was $8 million for a GRE, with the FAA contributing 80%. Respon- dents reported that ground noise control procedures are “very effective” at reducing noise complaints (52%) (see Figure 8).