Study of Airport Winds and Aircraft Noise Complaints. January 2016

Transcription

1 Study of Airport Winds and Aircraft Noise Complaints January 216 Environment Department, Noise Program Office Metropolitan Airports Commission 64 28th Avenue South, Minneapolis, MN 5545 MetroAirports.org

2 STUDY OF AIRPORT WINDS AND AIRCRAFT NOISE COMPLAINTS TABLE OF CONTENTS Section Page Executive Summary 2 1. Wind Direction Trends 3 2. Minneapolis-St. Paul International Airport Operations 8 3. Runway Use MSP Noise Complaints Conclusion 24 Appendix A1 LIST OF FIGURES 1.1 Historical MSP Wind Rose MSP Runway Geometry Monthly MSP Wind Roses Global Temperature Changes MSP Wind Rose Changes MSP Enplaned Passengers MSP Annual Operations MSP Load Factor MSP Large and Small Regional Jet Operations MSP Monthly Carrier Jet Counts by Type MSP Night Operations MSP Runway Configurations rd Quarter Runway Configurations th Quarter Runway Configurations MSP Complaints ( ) MSP Complaints and Operations (25-215) MSP Complaints and Operations ( ) MSP Nighttime Complaints Change in MSP Noise Complaints LIST OF TABLES 3.1 Runway Use System Zip Codes with Largest Change in Noise Complaints

3 Executive Summary The Minneapolis St. Paul International Airport (MSP) Noise Oversight Committee (NOC) 216 Work Plan includes a directive to Analyze Trends in Wind and the Relationship to Aircraft Noise Complaints. On November 18, 215, the members of the NOC approved the 216 Work Plan and directed Metropolitan Airports Commission (MAC) Noise Program Office staff to conduct a study with the following direction: Description: Wind direction and speed play a significant role in aircraft operational flows at the airport. This would be a detailed trend analysis on wind direction and speed as well as how these trends impact aircraft noise complaints. The Federal Aviation Administration (FAA) is constantly responding to changing weather patterns to allow aircraft and flight crews to conduct the safest operation possible. Runway use decisions are often predicated on the direction and speed of the wind. Often at MSP, winds in the summer are generally from the south and southeast with warmer temperatures than autumn and winter. This condition is reversed in the winter with winds generally from the north and northwest with colder temperatures. However, weather in 215 has not held to these norms. The autumn and winter of 215 have produced higher than average temperatures and more south and southeast winds than previous years. The amount of passenger enplanements at MSP made it the 16 th busiest airport in the country in 214. Passenger enplanements, the number of passengers boarding an aircraft, including originating and connecting passengers, have been on the rise at this airport for six years as the region and the nation recovers from a recession. The amount of aircraft operations required to move this increasing passenger traffic has not displayed a similar increase. More efficient airline reservation techniques have produced increasing load factors. Combined with a fleet transformation to bigger regional jets and more mainline jets, the amount of MSP aircraft traffic has declined 25% from a peak in 24. One area where an increase in operations was noted occurred between the hours of 1:3 PM and 6: AM, defined as nighttime at MSP. Aircraft are subjected to many possible runway configurations when they use MSP. These runway configuration decisions by the FAA are made by continuously evaluating numerous factors. Perhaps the most important are safety of the aircraft, efficiency of the airport and the airspace, and prevailing wind direction and speed. In addition to these primary considerations, the FAA also considers noise impacts from flight operations when choosing runway configurations and directing aircraft. Over the course of a year, air traffic is typically distributed over a large area, due to the various factors that influence runway configuration decisions. However, autumn and winter of 215 have produced many more days and months when the airport was in a south flow configuration instead of the expected north flow configurations. The prevalence of southerly winds, increased nighttime operations and the FAA s continuous use of south flow runway configurations led to an increase in aircraft noise complaints during 215. Specifically, increased numbers of aircraft noise complaints were submitted from areas of southern Eagan, northern Mendota Heights, Minneapolis and Minnetonka. Conversely, areas of Edina, southwest Minneapolis, and northern Eagan saw precipitous decreases. 2

4 1. Wind Direction Trends Since the birth of aviation, weather has always been an integral part of the flight planning process. Many factors are considered long before an airplane ever leaves the earth and begins its journey. Weather conditions are researched at the departure airport, arrival airport and points in between. Cloud type and ceiling levels, precipitation, sea level pressure and temperature are all taken into account. The most important factor may be wind. The safest operation for any aircraft during the landing phase of flight is to land the plane into the wind. Any headwind during this critical phase of flight helps to slow an aircraft from a speed capable of flight to speeds more appropriate for ground maneuvering while generating lift. Therefore, the wind direction and speed at an airport is the foundation for a host of operational decisions. While aircraft may operate with limited tail winds (less than seven knots), it is not ideal because higher ground speeds may lead to unsafe conditions upon landing. Wind direction and speed often determine which runways are used while historical wind patterns are a deciding factor in how the runways are oriented when they are planned and built. MSP, like every other airport, is subject to weather constraints. The wind rose, shown in Figure 1.1 below is a graphical representation of wind direction and speed at MSP from 197 through 215. A Wind Rose is a method of displaying wind patterns that occurred over a period of time (i.e., hour, day, week, year, decade, etc.). Each Wind Rose is a circle that displays directional headings consistent with a compass. The top of the circle represents north and the bottom is south. Bars, like spokes on a wheel, extend outward from the center of the circle and point to the compass heading representing the wind direction recorded during the selected time span. The length of the bars or arrows will represent the amount of time the wind blew from that direction. The color-coding on the bars show the wind speed. Figure 1.1 Source: Iowa Environmental Mesonet (IEM) 3

5 While MSP experiences wind from all directions, the dominant directions are out of the northwest and southeast. In accordance with Federal Aviation Administration (FAA) guidance, the MSP airfield has been designed to most closely resemble the wind patterns and provide the most wind coverage. FAA Advisory Circular 15/53-13 Appendix 1 provides airport planners the proper tools and guidance for selecting the most appropriate orientation of runways. A factor in influencing runway orientation and number of runways is wind. Ideally a runway should be aligned with the prevailing wind. Wind conditions affect all airplanes in varying degrees. Generally, the smaller the airplane, the more it is affected by wind, particularly crosswind components. Crosswinds are often a contributing factor in small airplane accidents. Airport planners and designers should make an accurate analysis of wind to determine the orientation and number of runways. In some cases, construction of two runways may be necessary to give the desired wind coverage (95 percent coverage). The proper application of the results of this analysis will add substantially to the safety and usefulness of the airport. MSP was designed consistent with this guidance and prevailing wind patterns. Figure 1.2 below shows the layout of the runways at MSP alongside the historical wind patterns. With the majority of the wind out of the northwest and southeast the North Parallel and South Parallel Runways (3L/12R and 3R/12L) were built to accommodate these wind patterns. Additionally, the Crosswind Runway (4/22) was built and is used in the unique circumstances when high winds from the northeast or southwest necessitate. The knowledge of airfield geometry is fundamental to understanding flight patterns around the metropolitan area. Figure 1.2 Source: Iowa Environmental Mesonet (IEM) While the wind has potential to change day to day or hour to hour, there are regional trends that exist. Figure 1.3 shows all the wind observations for the MSP airport from 197 through 214 for January, March, May, July, September and November. The dominant winds for January and February are out of the 4

6 northwest. March and April also see a large quantity of wind from the northwest; however, varying winds from the north and southeast begin to be more prevalent. Additionally, April experiences higher wind speeds on average. Wind directions in May through July are mixed in all directions with winds from the south and southeast observed most. August is accustomed to a lighter south and southeast wind. September is much the same with slightly higher speeds and slightly more variation in direction as the wind begins to shift back to the northwest before winter. Finally the winter chill begins in October with a northwest wind becoming increasingly pronounced into November and December. Wind rose data for each quarter from are available in the Appendix beginning on page A2. Figure 1.3 January March May July September November Source: Iowa Environmental Mesonet (IEM) The weather in autumn and winter 215 has not fit this regional wind pattern. Another important regional weather difference is temperature. The average autumn and winter temperature in this region has been significantly higher than average. Figure 1.4 from the National Weather Service Twin Cities/Chanhassen office demonstrates just how unusual the warm weather late in 215 has been. While the temperatures from last year during this time period were normal to slightly below normal, the temperatures in 215 are 5

7 4 C above normal. The warm temperatures are buoyed by the prevailing winds from the south instead of the seasonal north and northwest winds. Figure 1.4 Source: National Weather Service Twin Cities/Chanhassen September through December of a typical year would be dominated by north and northwest winds. Winds in September 215 were shockingly summer like. October returned to a far more normal condition. November again looked like a summer or autumn month and the first half of December was dry and unseasonably warm. Figure 1.5 compares recorded winds at MSP from September 215- December 215 against the same time period in 214. The lack of northwest winds in 215 coupled with the stronger than normal south winds is evident. 6

8 Figure Source: Iowa Environmental Mesonet (IEM) There are times when the surface wind condition is not the primary consideration in the FAA s runway configuration decisions. When this happens, decisions about runway use are made with higher consideration to air traffic efficiency and noise abatement. For example, high airport traffic demand levels may dictate a particular runway configuration to provide the greatest airport and airspace capacity so that traffic demand levels are managed in a safe and efficient manner. On occasion, the winds aloft, rather than the surface winds, become the determining factor in runway configuration decisions. These other factors often trump surface wind direction when the surface winds are less than seven knots. Additionally, the FAA must also consider a number of other variables that may affect the runway configuration, such as aircraft separation minimums, runway conditions and closures, meteorological conditions, visibility, navigation equipment maintenance, aircraft emergencies, pilot requests, aircraft weight and performance characteristics and aircraft de-icing activity. The FAA s runway configuration considerations are also discussed in Section 3. Runway use choices by air traffic control personnel and pilots will be impacted by weather conditions, especially wind. Historical weather patterns provide an expectation for how air traffic will be routed and what impact they may have on the surrounding community. The weather in 215 has not met those expectations and air traffic has been flying in areas not typical for the time of year. 7

9 2. Minneapolis-St. Paul International Airport Operations The FAA uses many metrics to rank the size of airports. Enplaned passengers, cargo tonnage, and aircraft operations are a few of the more common. In terms of 214 passenger enplanements, the FAA reports MSP was the 16 th busiest airport in the country. Passenger enplanements are the number of passengers boarding an aircraft, including originating and connecting passengers. In 214, 16,972,678 passengers boarded an airplane at MSP. This number represents a 4.25% increase from 213 when 16,28,835 passengers boarded an airplane at MSP. Figure 2.1 below provides passenger enplanement history for MSP back to 21. Enplanements dropped system-wide after 21 due to the September 11 terrorist attacks, then rose to a peak level in 25 before declining again from 25 to 21 due to the national economic recession. MILLIONS 2 19 Figure 2.1 MSP ENPLANED PASSENGERS Source: FAA Passenger Boarding Data It would be relatively easy to assume that the increase in enplaned passengers since 21 would produce a similar increase in aircraft traffic to support the nearly seventeen million passengers served in 214. However, annual aircraft operations at MSP as reported by the FAA are down 25 percent from the peak year in 24. An aircraft operation is either an aircraft takeoff or landing. Figure 2.2 details the annual operations for MSP as reported by the FAA from 21 through

10 Figure 2.2 6, 55, MSP ANNUAL OPERATIONS 54,727 5, 45, 4, 35, 44,128* 3, OPERATIONS * Source: FAA Operations Network (OPSNET) Airport Operations *Note: Totals for 215 are estimated due to the unavailability of FAA data at the time of the report. The recent decline is due largely to the ability of the airlines that serve MSP to optimize their aircraft fleets and schedules to more appropriately meet the needs and desires of the traveling public, both in the Minneapolis-St. Paul area, as well as the rest of the country. The United States Department of Transportation operates the Bureau of Transportation Statistics (BTS). One metric that the BTS records is load factor. Simply stated, the load factor shown in Figure 2.3 is a percentage of all seats at MSP that were filled. Figure % 86% 84% 82% 8% 78% 76% 74% 72% 7% 68% 66% 75.4% 72.9% 73.4% MSP LOAD FACTOR - ALL AIRLINES 78.5% 84.3% 85.3% 83.4% 82.9% 81.7% 82.2% 81.2% 81.5% 81.8%82.1% Source: US DOT Bureau of Transportation Statistics T-1 Segment Data 9

11 The past decade in the airline industry has been dominated by airline mergers. Delta Air Lines merged with Northwest Airlines. American acquired US Airways, Southwest Airlines merged with AirTran, while United Airlines and Continental Airlines became one airline. This consolidation has led to more optimized scheduling and intentional steps to limit the amount of empty seats flying from airport to airport. The initiative, at least in the minds of the business units at the airlines, has been successful. Airlines can now move more people and create more revenue with the same amount of resources just by more adequately filling the airplanes. In addition to the optimization of schedules, the airlines that serve MSP have also slowly transformed the aircraft fleet. At MSP, 34 seat turboprop aircraft have been phased out, and the use of 5 seat regional jets has also been declining. In their place are newer regional jets with greater than 7 seats. In much the same way as filling as many seats as possible, bigger regional jets require essentially the same resources per operation and become more advantageous to operate. Figure 2.4 shows the transition by the airlines to larger regional aircraft, since 21. Figure 2.4 LARGE AND SMALL REGIONAL JET OPERATIONS SMALL (< 7 SEATS) LARGE (> 7 SEATS) OPERATIONS THOUSANDS JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP Source: MACNOMS This transition is so pronounced that the MAC has begun considering facility improvements and modifications to accommodate a higher prevalence of larger regional jets. The A and B concourses at MSP were designed to facilitate the ground movement of 34 seat turbo props, 5 seat regional jets as well as larger regional jets. With the turboprops phased out and smaller regional jets being operated far less than previously, the gate parking spaces are constrained and are being reconfigured. In much of the same way that regional jet operators are increasing efficiency, mainline airline carriers at MSP are flying more routes than their regional partners. Figure 2.5 illustrates the relationship between the 1

12 operations of mainline jets flying with manufactured Stage 3 engines versus regional jets. Regional Jet operations had outpaced those on mainline carriers for much of the early part of this decade. In June 214 that ratio was reversed and has been widening for much of 215. Figure 2.5 MONTHLY CARRIER JET COUNTS BY TYPE THOUSANDS MANUFACTURED STAGE 3 REGIONAL JET OPERATIONS JAN APR JUL OCT JAN APR JUL OCT JAN APR JUL OCT JAN APR JUL OCT JAN APR JUL OCT JAN APR JUL OCT Source: MACNOMS While overall aircraft operations at MSP have decreased, the number of flights during the nighttime and early morning hours has risen. MSP nighttime is defined as 1:3 PM to 6: AM. From 21 through 215, nighttime operations peaked in 27. Nighttime operations declined through 212, then began to increase. Figure 2.6 shows the history of nighttime operations at MSP, as reported by the MAC Noise and Operations Monitoring System (MACNOMS) from 21 through 215. As the airport operator, the MAC is not able to implement access restrictions that would limit the time of day, type of aircraft, or business that wishes to operate at this facility. There is, however, a voluntary agreement with the airlines servicing MSP to limit the scheduling of operations after 1:3 PM and before 6: AM. While the MAC monitors operations during these hours, and encourages adherence to the agreement, it remains voluntary. 11

13 Figure 2.6 MSP NIGHTTIME OPERATIONS NIGHT OPERATIONS PERCENT OF OPERATIONS AT NIGHT OPERATIONS THOUSANDS % 3.2% % 3.7% % 4.6% % 6.% % 4.8% 4.6% 3.8% 4.1% 3.8% 3.9% 1% 8% 6% 4% 2% % NIGHT OPERATIONS(%) Source: MACNOMS MSP continues to process a considerable amount of goods and passengers through the facility annually. Passengers and cargo counts are on the rise as a result of an improving economy both in the MSP service area as well as nationally. An updated business model and achieved efficiencies by many of the airlines that serve this area has not led to a resultant increase in aircraft operations at MSP. Instead, aircraft operations at MSP peaked in 24 and have been gradually declining since. The overall decrease in air traffic has been accompanied by an increase in nighttime operations to levels last seen in

14 3. Runway Use The FAA is tasked with directing all aircraft in and out of MSP and employs a variety of runway configurations to safely and efficiently route aircraft both on the ground and in the air. FAA Air Traffic Control (ATC) takes into consideration numerous factors, including: safety, efficiency, current and forecasted wind direction and wind speed (on the surface and aloft), air traffic demand, aircraft weight, the number of inbound and scheduled outbound aircraft, runway closures, metrological conditions, noise abatement procedures, navigation equipment maintenance, aircraft emergencies, pilot requests, aircraft de-icing activity and many other variables when selecting an airport configuration. This complex decision-making process also includes consideration of the Runway Use System (RUS). Table 3.1 highlights the priority ranking for the runways at MSP. The RUS has been developed at MSP to promote flight activity over less-populated residential areas to the south and southeast as much as possible. The areas to the south and southeast are less densely populated and include the Minnesota River, Interstate 494, Minnesota Highway 5 and commercial/industrial zoned parcels in Eagan and Mendota Heights. Conversely, the areas to the north and northwest are more densely populated residential parcels. Table 3.1 Departures Arrivals Runways 12L and 12R Runways 3L and 3R Runway 17 Runway 35 Balanced Use of Runway 4-22 Balanced Use of Runway 4-22 Runways 3L and 3R Runways 12L and 12R In ideal conditions, aircraft would depart the airport to the south on Runways 12L, 12R and 17 while arriving aircraft would approach the airport from the south and arrive on Runways 3L, 3R, and 35. This configuration is referred to as an opposite direction (O) configuration. Due to the aforementioned conditions, specifically safety, efficiency, wind and demand, this condition is rarely possible. Aircraft using runways in opposite directions would be in conflict if they crossed paths, thereby requiring significant aircraft spacing requirements and limiting the efficiency of the airspace. Furthermore, aircraft must land and take off into the wind as much as possible to increase the margin of safety. Figure 3.1 depicts the potential MSP runway configurations. The dominant configurations at MSP are north flow or south flow. The two conditions that are not pictured are the opposite direction configuration, explained above, and unusual configuration (U), which can take different forms, such as use of the Runway 4/22. 13

15 Straight North Flow (N*) Figure 3.1 North Flow (N) Straight South Flow (S*) South Flow (S) Mixed A (MA) Mixed B (MB) Different runway configurations will result in overflights over different communities. North flow (N) operations will result in arrivals over Mendota Heights, Eagan, Bloomington, and Apple Valley with departures proceeding over Minneapolis. Due to weather, wind conditions or construction, there are times when the FAA uses a straight north flow (N*), which eliminates the use of Runway 35 for arrivals and thus 14

16 results in arrivals over Mendota Heights and Eagan with departures proceeding over Minneapolis. South flow (S) operations will result in arrivals over the northwest suburbs including St. Louis Park, Minnetonka and others before traveling over Minneapolis while the departures will fly over Mendota Heights, Eagan, Bloomington, Burnsville and Apple Valley. In a straight south flow (S*) configuration, Runway 17 is no longer used for departures, resulting in arrivals over St. Louis Park, Minnetonka and Minneapolis with departures proceeding over Mendota Heights and Eagan. The mixed flow A (MA) configuration is similar to the straight north flow except Runway 17 is used for departures over the Minnesota River Valley instead of residential area to the north in Minneapolis. Mixed flow B (MB), where aircraft are departing over Mendota Heights and Eagan with arrivals over Bloomington, Eagan and Apple Valley, is rarely used due to the FAA s separation requirements and space constraints. The use of runway configurations ebb and flow with the seasonal wind conditions. North or straight north flows are more dominant in the late autumn, winter and early spring seasons while south or straight south flows are more typical in the late spring, summer and early autumn. As discussed in Section 1, the wind and temperature patterns in 215 have deviated from seasonal norms. The Appendix shows quarterly Runway Configuration percentages from 211 through 215 beginning on page A7. Figure 3.2 shows 3 rd quarter (July-September) runway configuration percentages while Figure 3.3 illustrates the 4 th quarter (October- December) for 211 through 215. Due to the unseasonable weather conditions in 215, the 3 rd and 4 th quarters have seen a noticeable change in runway configuration percentages. Figure 3.2 3RD QUARTER RUNWAY CONFIGURATIONS MA MB N N* O S S* U 45.% 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 3RD Q 3RD Q 3RD Q 3RD Q 3RD Q MA 9.1% 8.6% 7.9% 7.4% 1.7% MB.1%.4%.1%.%.% N 41.4% 41.2% 31.% 31.2% 1.3% N* 6.5% 7.% 6.1% 9.3% 16.% O 11.% 11.3% 8.6% 8.7% 8.% S 21.6% 21.5% 31.3% 28.8% 37.5% S* 1.% 9.8% 15.% 14.7% 17.6% U.3%.1%.%.1%.% Source: MACNOMS 15

17 The 3 rd quarters of 211 and 212 were dominated by north flows with the airport set up in a north or straight north configuration 47.9% and 48.2% of the time, respectively. The 3 rd quarters of 213 and 214 saw a more balanced use of the runway configuration. The 3 rd quarter of 215 was led by south flows. South and straight south flow configurations were used 55.1% of the time due to the wind patterns described in Section 1. Figure 3.3 4TH QUARTER RUNWAY CONFIGURATIONS MA MB N N* O S S* U 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 4TH Q 4TH Q 4TH Q 4TH Q 4TH Q MA 7.7% 6.9% 1.1% 6.% 7.1% MB.%.2%.%.%.2% N 34.7% 29.6% 32.3% 27.8% 15.4% N* 1.8% 13.3% 16.8% 18.7% 18.3% O 13.2% 11.% 1.3% 9.9% 8.1% S 21.9% 26.% 2.4% 22.1% 32.2% S* 11.6% 13.1% 1.1% 14.7% 18.4% U.1%.%.%.8%.3% Source: MACNOMS This condition persisted well into the 4 th quarter of 215. In typical seasonal conditions, the airport begins to transition into north flow configurations during this quarter as shown in Q During these quarters, the airport was in either north flow or straight north flow configurations for an average of 46.% of the time and in south or straight south flow configurations for an average of 35.% of the time. In 215 the numbers were reversed. South flows were present 5.6% of the time compared to just 33.7% for north flow configurations. This contrast from historical conditions has resulted in an increase in departing flights over Mendota Heights, Eagan, Bloomington, and Apple Valley with increases in arriving flights over Minneapolis, St. Louis Park, Minnetonka and other northwest suburbs. Corresponding decreases in arrivals over Mendota Heights, Eagan, and Inver Grove Heights have been accompanied by decreases in departures over Minneapolis, Edina and Richfield. Choosing which runways to use is a complex and dynamic process involving a variety of frequently changing variables. The FAA and the MAC take every step to ensure the safety of the people using MSP. When feasible, measures to limit the impact of aircraft noise on the surrounding community are considered and sometimes implemented. 16

18 4. MSP Noise Complaints The previous sections provide concrete information about MSP weather patterns affecting MSP aircraft operations and runway configurations in an effort to supplement inconclusive noise complaint data provided in this section. The Minneapolis-St. Paul metropolitan region would not be the thriving, livable area that it is without a world class airport. This facility is a major asset for the region and the state. The MAC is constantly balancing all of the benefits MSP provides against the challenges that present themselves when operating an airport of this significance. Since 212, aircraft noise complaints associated with MSP have been increasing. In 215, growth in complaints saw month over month gains in 12 out of 12 months from 214. Similarly, 214 saw month over month gains in 11 out of 12 months over 213 which saw similar gains over 212. Due to the complexity of runway use and flight patterns, the slow transformation of the aircraft fleet utilizing MSP, the sophistication of airline scheduling, and the ever-changing weather patterns, it can be challenging to decipher how minor changes are impacting specific neighborhoods or even broader communities. While investigating MSP noise complaints provides intrinsic value to MAC staff and policy makers, MSP noise complaints as a standalone metric does not and cannot fully explain these changes. Due to the nature of noise complaints both what they represent, and how they are acquired noise complaints have increasingly less predictive value to potential future expectations. The MAC strives to be transparent and communicate with individuals, neighborhoods and communities about where planes fly, how high above the ground they are, noise levels recorded at Remote Monitoring Towers, and the Annual Day-Night Average Sound Levels (DNL) for each year. The challenge lies in how noise impact is quantified. The FAA dictates what noise metric airports will use for determining noise impacts around all United States airports and what can be done to mitigate impacts. These federally required metrics authorize the FAA to wield a considerable amount influence into this arena. The MAC consistently reports alternative noise metrics to better quantify and communicate the impacts of aircraft noise, and noise mitigation is provided to the 6 db DNL noise contour, well beyond the FAA s threshold of 65 db DNL. One simple and objective metric of noise impact does not exist. Noise is defined as unwanted sound, but unwanted sound to one person is different to another. The challenge to the MAC, and all airports, is determining the root causes leading one to file an aircraft noise complaint. Further, what are the circumstances that lead one to file more complaints than last month or last year? The bevy of variables that exist in the simple act of filing a noise complaint are endless. A study done in 29 at the Philadelphia Airport correctly notes: One of the difficulties in assessing noise impacts, particularly at levels where direct health hazards are not a major factor, is that noise is largely an issue of sensory perception and personal preference. Noise, by its definition, is an unpleasant or unwanted sound. A sound characterized as noise can be accurately measured as a vibration or a change in air pressure, but what makes it noise is a matter of perception Collette, J. D. (211). Self-Reported Aircraft Noise Complaints and Socioeconomic Demographics in the Greater Philadelphia Region: A Survey of Complaint Data from 1997 to 29. Journal of Aviation Technology and Engineering,

19 For these reasons, a study of noise complaints for MSP, or any airport, must be qualified with the understanding that the MAC cannot list every variable present when an individual decides to log an aircraft noise complaint. Data presented in reference to flight activity, flight tracks, weather, and runway configuration are indisputable. Information about noise complaints, beyond the sum of complaints filed, is far more complicated. In stark contrast to our flight track and noise event data, which undergo numerous quality control checks, the noise complaint data is an unfettered pipeline direct from the residents. As such, the community is responsible for the validity of complaint data in our current data collection process. Under current procedures, the MAC does not invalidate noise complaints for any reason. If a complaint is received from any residential address in the seven-county metropolitan area, regardless of correlated or uncorrelated flight activity, it will be documented and reported. The number of MSP aircraft noise complaints and the number of households that filed complaints are shown in Figure 4.1 below Figure 4.1 MSP AIRCRAFT NOISE COMPLAINTS 16, 14, COMPLAINTS *See Note in Appendix regarding Noise Complaints from Spring 211 HOUSEHOLDS 1,6 1,4 12, 1,2 COMPLAINTS 1, 8, 6, 4, Area Navigation (RNAV) public open house meetings (November 212) 1, , 2 JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV HOUSEHOLDS Source: MACNOMS The number of households submitting at least one noise complaint peaked in August 215, while the 12,827 complaints submitted in June 215 were the most since 211. While there are some factors that have led to the increases which will be discussed later, the full extent of the increase cannot be fully explained, even with the incredible amount of data collected and researched by the MAC. It is further confounding that while the number of flights actually occurring at MSP is decreasing, the number of complaints continues to grow. Figure 4.2 shows the rise of the ratio of aircraft noise complaints to aircraft operations. 18

20 Figure 4.2 MSP AIRCRAFT NOISE COMPLAINTS AND OPERATIONS COMPLAINTS THOUSANDS COMPLAINTS % 13.5% % 12.5% 53.4 PERCENTAGE OF COMPLAINTS TO OPERATIONS % % % % 3% 28.% 25% 2% 15% 1.5% 1% 5% COMPLAINTS / OPERATIONS Source: MACNOMS % The MAC receives complaints primarily in two ways: 1) people may call the MAC complaint phone number and leave a message with the details of their complaint. Staff will then use the information provided to file the complaint; 2) people may access the online complaint form, available on the MAC Noise Program Office website to enter the details of the complaint and file the complaint without any staff interaction. Over 9% of the aircraft noise complaints logged for MSP are submitted through the MAC Noise Program Office website. Due to the wealth of information contained on the MAC Noise Program Office website, MAC staff are hopeful that individuals are spending time doing personalized research into their specific area of interest. However, the noise complaint system, as it is operated today, allows individuals to file multiple noise complaints for a single aircraft operation or file noise complaints for multiple households. When unverified complaints are filed with no determination as to the source of the noise, the quality of the noise complaint dataset is degraded. When noise complaints are compared to actual operations, it should be expected that fewer flights will produce fewer complaints and more flights will produce more complaints. In some regards, this condition does occur. At MSP the weekdays are the busiest for airport operations. Conversely, Saturday has the least amount of operations; Sunday is the second lowest. It should hold then that Saturday and then Sunday should produce the fewest noise complaints. This is only partially true. Saturdays are the days with the fewest noise complaints, averaging 6 complaints less than the next day of the week. The relationship 19

21 between flight activity and complaints fails on Sundays. Instead of having the second fewest complaints to correlate with the second slowest day of the week in flight activity, Sunday was the busiest day for aircraft noise complaints in 215. Flight totals and complaint totals are not directly proportional, due to the subjective nature of complaints. Section 2 of this report discussed the decreases in MSP aircraft operations over the last decade. Over the course of this time period, these decreases have led to shrinking noise exposure areas overall. While some areas may experience more noise as a product of runway configurations, the overall noise exposure area has contracted. However, the receding noise exposure area has been accompanied by increasing complaints. Figure 4.3 shows how every month in 214 had less air traffic than 213 while 1 of 12 months in 215 had less air traffic than 214, yet complaints were up every month. Figure COMPLAINTS 214 COMPLAINTS 215 COMPLAINTS 213 FLIGHTS 214 FLIGHTS 215 FLIGHTS MSP NOISE COMPLAINTS THOUSANDS THOUSANDS MSP OPERATIONS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Source: MACNOMS The nighttime hours are a particularly sensitive time for individuals. The same airplane with the same configuration will seem louder at night due to lower ambient noise levels that typically occur. In the spring and summer of 215, the MSP Noise Oversight Committee discussed and evaluated an increase in both nighttime operations and related noise complaints. As stated in Section 2, the MAC is prohibited from restricting nighttime flight activity. The combination of increased air traffic during the nighttime hours has resulted in a rise in both the total nighttime complaints and percentage of total complaints received at night. Figure 4.4 depicts total complaints and nighttime complaints. 2

22 COMPLAINTS THOUSANDS % 14.5% 11.8% 1.3% Figure 4.4 MSP COMPLAINTS ALL COMPLAINTS NIGHT COMPLAINTS PERCENTAGE OF COMPLAINTS AT NIGHT 8.1% 6.6% % % 6.9% 6.1% 6.3% 6% % 18% 16% 14% 12% 1% 9.6% 4% 2% % NIGHT COMPLAINTS (%) Source: MACNOMS Regardless of the reason that complaints associated with MSP flight activity have increased, there has been stark shifts in the origin of the complaints. Sections 1, 2 and 3 all detailed the change in air traffic due to runway configurations and a higher prevalence of south winds well into the 4 th quarter of 215. The result of those swings from the perspective of noise complaints can be seen in many areas. Zip codes were used to evaluate smaller segments of cities, due to the variability of aircraft traffic throughout a given city. Table 4.1 lists the ten zip codes with the most change in noise complaints from 214 to 215. Edina zip codes 55439, and 5541 accounted for a drop of nearly 14, complaints. This change is driven by runway configuration. With less time spent in north flow or straight north flow configurations, departure flights from Runways 3L and 3R decreased, reducing the flight traffic over these areas of Edina. Additionally, two households in Edina zip code who were responsible for almost 6 percent of the Edina noise complaints in 214 reduced the number of noise complaints in 215 by about 45 percent. Zip code in Eagan also recorded a major drop in complaints filed as aircraft were approaching Runway 3L over Eagan less often. Conversely, complaints grew from zip codes to the south of the airport off the departure end of Runway 17, east of the airport off the departure end of Runway 12L and northwest of the airport under arrival paths for Runways 12L and 12R. Zip codes and in Eagan recorded 6,281 more complaints in 215 than 214. The area off of the Runway 12L departure path, zip code in Mendota Heights, recorded 2,83 21

23 more complaints this year. Finally under the Runways 12L and 12R arrival paths, Minneapolis areas 5549, 55417, and were responsible for 9,733 more complaints this year than last. Additionally, 5535 in Minnetonka produced 842 more complaints this year due to arrival traffic inbound to Runway 12R. These increases are due to the heavy use of south flow and straight south flow configurations in 215. There are two areas that do not fit this pattern. The growth of 5,265 complaints from zip code in Golden Valley is the result of the efforts of one household, which began submitting noise complaints more frequently beginning in April 215. Zip code 5546 in eastern Minneapolis saw a similar jump in complaints from 214 to 215 as it did from 213 to 214. Figure 4.5 details the change in for all of the zip codes surrounding the airport. An enlarged figure is also available in the Appendix on page A11. The Appendix also details noise complaints for all of the NOC communities beginning on page A12. Table 4.1 City Zip Code 215 Change 215 Percent Change Edina , % Edina , % Eagan ,6-59.2% Edina / Minneapolis , % Mendota Heights % Minneapolis % Minneapolis % Farmington % Fridley % Brooklyn Center / Minneapolis % Eagan , % Golden Valley , % Minneapolis , % Minneapolis , % Mendota Heights / West St. Paul , % Minneapolis , % Minneapolis , % Bloomington , % Minnetonka % Eagan % Source: MACNOMS 22

24 Figure 4.5 Source: MACNOMS Noise exposure is a negative consequence that is constantly weighed against the benefits of a world-class international airport in an urban environment. MSP air traffic has been declining in recent years. Additionally, each year the actual noise contours at MSP continue to show stable or shrinking noise exposure overall. The 214 actual noise contour is 44 percent smaller in the 6 DNL contour and 52 percent smaller in the 65 DNL contour than the contour that was forecast for the year 27. Moreover, the MAC has committed to provide noise mitigation to areas most exposed to current aircraft noise; however, noise complaints have continued to rise. This rise can be attributed to known, quantifiable contributors such as an increase in nighttime flights and increased south flow operations. Unfortunately, the increase in complaints can also be credited to misinformation and unquantifiable sources, such as media reports, general community awareness, overall frustration toward the airport, changes in personal lifestyles and routines, as well as airport noise issues in other areas of the country. 23

25 5. Conclusion Wind and its effect on runway use have a major impact on the location and extent of flight activity in different areas of the Minneapolis-St. Paul area. Historical wind data indicate that typical autumn and winter weather patterns produce north and northwest winds. In 215, autumn and winter did not produce typical north winds. With warmer temperatures and a higher prevalence of south winds, a south flow configuration was necessary far more often than previous years. With south flow configurations lasting longer into the 3 rd and 4 th quarters of 215, areas in Minneapolis, St. Louis Park and other northwest suburbs experienced more arrival flights than previous years, while Eagan, Mendota Heights, Bloomington, and other areas to the south and southeast saw an increase in departure traffic. Although some areas did see more aircraft traffic, the amount of aircraft operations at MSP are down from 214. This decrease is a continuation of a decline that began in 24. This consistent decrease is primarily the result of airlines moving more passengers on fewer flights by increasing load factors and flying larger aircraft. While overall aircraft operations are down, nighttime operations have increased. The MAC actively monitors nighttime activity; however, the MAC is unable to restrict these operations. The FAA s continuous use of south flow increased nighttime flights have contributed to increases in aircraft noise complaints filed. However, there is a litany of variables that leads one to file a noise complaint, which may not be limited to the noise produced by an aircraft overhead. Therefore, it becomes difficult to quantify and fully explain the complete list of conditions that have led to the increase in aircraft noise complaints. The current procedures of the MAC s Noise Program Office to document and report aircraft noise complaints does not undergo quality checks or validity processing. Any noise complaint received from a residential address in the seven-county metropolitan area will be documented and reported. At times, this leads to noise complaints submitted for MSP, when the noise was associated with a different airport operation. The Noise Program Office is interested in evaluating improved processes to document and report aircraft noise complaints in a manner that would be more valuable to the MSP Noise Oversight Committee and to the public. 24

26 APPENDIX Section Page Wind Rose Charts ( ) A2 Runway Configuration Charts A7 211 Noise Complaint Evaluation A1 Noise Complaint Change by Zip Code A11 Noise Complaints by City A12 A 1

27 Wind Rose Charts 211 Quarter 1 Quarter 2 Quarter 3 Quarter 4 A 2

28 Wind Rose Charts 212 Quarter 1 Quarter 2 Quarter 3 Quarter 4 A 3

29 Wind Rose Charts 213 Quarter 1 Quarter 2 Quarter 3 Quarter 4 A 4

30 Wind Rose Charts 214 Quarter 1 Quarter 2 Quarter 3 Quarter 4 A 5

31 Wind Rose Charts 215 Quarter 1 Quarter 2 Quarter 3 Quarter 4 Source: Iowa Environmental Mesonet (IEM) A 6

32 Runway Use Configuration Charts by Quarter 45.% MA MB N N* O S S* U 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 1ST Q 2ND Q 3RD Q 4TH Q 211 MA 8.9% 5.1% 9.1% 7.7% MB.1%.2%.1%.% N 3.3% 26.6% 41.4% 34.7% N* 17.3% 12.1% 6.5% 1.8% O 9.4% 9.1% 11.% 13.2% S 18.2% 29.4% 21.6% 21.9% S* 15.7% 17.% 1.% 11.6% U.1%.6%.3%.1% MA MB N N* O S S* U 45.% 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 1ST Q 2ND Q 3RD Q 4TH Q 212 MA 7.7% 6.7% 8.6% 6.9% MB.%.1%.4%.2% N 32.8% 3.4% 41.2% 29.6% N* 12.4% 6.9% 7.% 13.3% O 11.3% 1.8% 11.3% 11.% S 22.6% 3.% 21.5% 26.% S* 13.2% 15.% 9.8% 13.1% U.%.2%.1%.% A 7

33 Runway Use Configuration Charts by Quarter 45.% MA MB N N* O S S* U 4.% 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 1ST Q 2ND Q 3RD Q 4TH Q 213 MA 6.2% 5.% 7.9% 1.1% MB.1%.2%.1%.% N 38.1% 27.3% 31.% 32.3% N* 17.7% 15.7% 6.1% 16.8% O 11.% 8.6% 8.6% 1.3% S 15.6% 25.8% 31.3% 2.4% S* 11.2% 17.4% 15.% 1.1% U.%.1%.%.% 4.% MA MB N N* O S S* U 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 1ST Q 2ND Q 3RD Q 4TH Q 214 MA 7.1% 6.6% 7.4% 6.% MB.1%.1%.%.% N 36.8% 22.% 31.2% 27.8% N* 19.% 14.2% 9.3% 18.7% O 1.4% 9.7% 8.7% 9.9% S 15.8% 3.3% 28.8% 22.1% S* 1.7% 16.9% 14.7% 14.7% U.1%.2%.1%.8% A 8

34 Runway Use Configuration Charts by Quarter 4.% MA MB N N* O S S* U 35.% 3.% 25.% 2.% 15.% 1.% 5.%.% 1ST Q 2ND Q 3RD Q 4TH Q 215 MA 1.4% 5.1% 1.7% 7.1% MB.1%.%.%.2% N 29.7% 26.9% 1.3% 15.4% N* 14.9% 12.7% 16.% 18.3% O 11.4% 8.8% 8.% 8.1% S 22.9% 27.8% 37.5% 32.2% S* 1.5% 17.6% 17.6% 18.4% U.2% 1.1%.%.3% Source: MACNOMS A 9

35 211 Noise Complaint Evaluation The following 26 locations in Minneapolis collectively had not issued a formal noise complaint with the Metropolitan Airports Commission prior to February 211. From February 211 through May 211, these locations filed 22,695 complaints (all via internet). Since that time, these locations have filed 12 complaints. It is the belief that this was a coordinated effort by an individual or a group of individuals to skew the complaint numbers at that time for reasons unknown to the MAC. These residences did not provide contact information, nor was any communication established with MAC staff. Each complaint was received and reported as a valid complaint and continues to be reported in this report and any other documentation that references complaints from this time period. Year Month Complaints Filed 211 Feb Mar 8, Apr 11, May 2, Aug Jan Apr May Jun 1 Source: MACNOMS A 1

36 A 11

37 Noise Complaints by City Apple Valley NOISE COMPLAINTS/HOUSEHOLDS 1,8 1,6 1,4 1,2 1, MSP NOISE COMPLAINTS COMPLAINTS HOUSEHOLDS ,431 1,162 1, MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION ,2 1, NOISE COMPLAINTS MA N N* S S* , A 12

38 Noise Complaints by City Bloomington 3, MSP NOISE COMPLAINTS COMPLAINTS HOUSEHOLDS 2,5 NOISE COMPLAINTS/HOUSEHOLDS 2, 1,5 1, , MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION NOISE COMPLAINTS MA N N* S S* *Note: The 215 increase noise complaints submitted in 215 during north flow (N) and straight north flow (N*) is largely the result of one household responsible for numerous complaints. A 13

39 Noise Complaints by City Burnsville 9 MSP NOISE COMPLAINTS 8 COMPLAINTS HOUSEHOLDS NOISE COMPLAINTS/HOUSEHOLDS MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION NOISE COMPLAINTS MA N N* S S* A 14

40 Noise Complaints by City Eagan 3, MSP NOISE COMPLAINTS NOISE COMPLAINTS/HOUSEHOLDS 25, 2, 15, 1, 5, 19,322 18,986 2,739 22,191 26, , MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION , NOISE COMPLAINTS 15, 1, 5, MA N N* S S* , , , ,43 1, ,25 2,274 1,674 12,466 1, ,74 1,383 15,73 1, ,192 1,369 1,973 19,161 1,785 A 15

41 Noise Complaints by City Edina 3, MSP NOISE COMPLAINTS COMPLAINTS HOUSEHOLDS NOISE COMPLAINTS/HOUSEHOLDS 25, 2, 15, 1, 5, 2,275 1, ,422 25,796 12, MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION NOISE COMPLAINTS 2, 18, 16, 14, 12, 1, 8, 6, 4, 2, MA N N* S S* , , ,862 1, ,91 4, ,661 2, A 16

42 Noise Complaints by City Inver Grove Heights 8 MSP NOISE COMPLAINTS 7 NOISE COMPLAINTS/HOUSEHOLDS MSP NOISE COMPLAINTS BY RUNWAY CONFIGURATION NOISE COMPLAINTS MA N N* S S* A 17