HomeMy WebLinkAbout2012-11-00-rpt (Annual Noise Report)PREPARED BY
SHARON,.WILLIAMS-
SUBMITTED TO
HANSCOM FIELD ADVISORY COMMISSION
November 2012
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Connecting with our communities
MASSACHUSETTS PORT AUTHORITY Page i
TABLE OF CONTENTS
INTRODUCTION............................................................................................ ..............................1
CHAPTER1 SUMMARY .............................................................................. ..............................2
CHAPTER 2 HISTORICAL PERSPECTIVE ON THE ANNUAL REPORT AND THE
EVALUATIONOF NOISE .................................................... ..............................4
2.1 The Use of Contours to Evaluate Noise Exposure ....................... ..............................4
2.2 Developing EXP to Evaluate Changes in Noise Exposure .......... ..............................5
2.3 The Significance of Changes in EXP ........................................... ..............................6
2.4 Upgrading EXP Calculations ....................................................... ..............................6
2.5 UP Focus: With Single Engine Piston (SEP) vs. Without SEP, With Military
Aircraft vs. Without Military Aircraft, Departure EXP vs. Arrival EXP ...................7
2.6 The Report on 2011 Noise Exposure ........................................... ..............................7
CHAPTER 3 DATA COLLECTION FOR DETERMINING OPERATIONS AND NOISE
EXPOSURE.............................................................................. ..............................8
CHAPTER 4 2011 OPERATIONS, 7 a.m. -11 p. m ...................................... .............................10
CHAPTER 5 11 P.M. to 7 A.M. OPERATIONS ...........................:............. .............................17
CHAPTER 6 NOISE EXPOSURE LEVELS .............................................. .............................20
6.1 2011 EXP Version 6. 1 ................................................................. .............................20
6.2 EXP Comparisons for Study Years, 1978 -2011 .......................... .............................22
6.3 Analysis of Changes in Annual EXP for Study Years, 1978 - 2011 ..........................
27
CHAPTER 7 NOISE MONITORING SYSTEM ........................................ .............................30
CHAPTER 8 NOISE ABATEMENT POLICIES ....................................... .............................32
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List of Figures
FIGURE 4.1
List of Tables
FIGURE 4.2
TABLE 3.1
Data Sources for Civilian Aircraft ............................................... ..............................9
FIGURE 4.3
TABLE 4.1
Annual FAA Tower Counts for 7 a.m. to 11 p.m. Since 1978 .. .............................11
FIGURE 5.1.
TABLE 4.2
Annual Estimated Operations by Aircraft Type, 7 a.m. -11 p. m .............................12
FIGURE 6.1
TABLE 4.3
Estimated Average Daily Departures *, 7 am.-1 1 p.m. by Single Engine Piston
Differences Between Civilian Departure EXP for Study Years 1978-2001
........... 25
Aircraftfor Study Years ............................................................. .............................14
Differences Between Civilian Departure EXP for Study Years 2000-2011
TABLE 4.4
2011 Monthly Average Daily Departures by Non - Single Engine Piston Aircraft..
14
TABLE 4.5
Annual Average Daily Departures by Non -SEP Aircraft for Study Years .............16
TABLE 5.1
11 p.m. to 7 am. Operations Since Nighttime Fee was Instituted ..........................18
TABLE 5.2
Breakdown. of 2011 11 p.m. to 7 am. Operations ...................... .............................19
TABLE 6.1
2011 Monthly Variations in Departure EXP 6. 1 ........................ .............................20
TABLE 6.2
Contributions to Civilian Departure EXP for 2011 Operations . .............................22
TABLE 6.3
Civilian Departure EXP Comparisons, 1978 - 2001 .........:.......... .............................23
TABLE 6.4
Civilian Departure EXP Comparisons, 2000 - 2011 .................... .............................24
TABLE 6.5
EXP 6.1 Values for 2000 and 2005 through 2011 ..................... ................:............26
TABLE 7.1
Measured DNL Levels -1995, 2000 and 2005 Through 2011 .. .............................31
List of Figures
FIGURE 4.1
Annual FAA Tower Counts for 7 am. to 11 p.m. Since 1978 ... ............................:11
FIGURE 4.2
Monthly Average Daily Departures by Non -SEP Aircraft, 2011 ............................15
FIGURE 4.3
Annual Variations in Average Daily Departures by Non -SEP Aircraft ..................17
FIGURE 5.1.
Annual 11 p.m. to 7 a.m. Operations since Nighttime Fee was Instituted ..............19
FIGURE 6.1
2011 Monthly Averages in Departure Noise Exposure EXP 6. 1 ............................21
FIGURE 6.2
Differences Between Civilian Departure EXP for Study Years 1978-2001
........... 25
FIGURE 6.3
Differences Between Civilian Departure EXP for Study Years 2000-2011
........... 25
FIGURE 6.4
Average Daily Jet Departures by SEL Groups, 2000, 2005, 2010 & 2011 .............27
FIGURE 6.5
Stage 2 Jet Activity, 2000 - 2011 ................................................. .............................29
FIGURE 7.1
Measured DNL Values -1995, 2000, and 2005 through 2011 .. .............................32
Appendices
APPENDIX A Noise Terminology Used at Hanscom Field and DNL Noise Contour Maps
APPENDIX B 2011 Average Daily Operations and Noise Exposure by Aircraft Type
APPENDIX C 1995, 2000 and 2005 through 2011 Measured DNL (dBA) at Hanscom Noise
Monitoring Sites
MASSACHUSETTS PORT AUTHORITY Page
INTRODUCTION
Each year, the Massachusetts Port Authority prepares a noise report for L.G. Hanscom Field, a
tool used by Massport to report on aircraft activity and the noise environment at the airport. It
includes a historical perspective on why and how noise impact reports have been presented since
1982, and continues with data on the numbers and types of operations and overall noise exposure
for the most recent calendar year. This report has been prepared to present data on Hanscom
Field's 2011 operations. Comparable data from previous study years (1978, 1981, and 1983
through 20 10) demonstrate trends in aviation activity and noise levels.
The Massachusetts Port Authority
The Massachusetts Port Authority (Massport) operates Boston Logan International Airport, L.G.
Hanscom Field, Worcester Regional Airport, and public terminals in the Port of Boston.
Massport is a financially self - sustaining public authority whose premier transportation facilities
generate over $8 billion dollars in economic activity every year and support over 20,000 direct
jobs, which enhances and enables economic growth and vitality in New England. Massport is
committed to providing safe, secure and efficient transportation facilities that afford travelers and
businesses the freedom to travel and conduct business throughout the world while enabling
Massachusetts and New England to compete successfully in the global marketplace. No state tax
dollars are used to fund operations or capital improvements at Massport facilities.
L. G. Hanscom Field
In 1941, the Commonwealth of Massachusetts purchased land northwest of Boston for the
proposed Boston Auxiliary Airport, and the U.S. Civil Aeronautics Administration oversaw
construction of the original runways and facilities. The completed facility was immediately
leased by the Army Air Corps for advanced pilot training in support of America's war effort. In
1943, the new airport, geographically bounded by Bedford, Concord, Lexington and Lincoln,
was officially dedicated as Laurence G. Hanscom Field.
In 1956, the Massachusetts legislature created the Massachusetts Port Authority and gave it
control of Hanscom Field. In 1959, Massport began managing the civil terminal area while the
U.S. Air Force leased and operated the airfield for continued use by military and civilian aircraft.
In 1974, the Air Force canceled its lease of the airfield, and Massport became responsible for
operating and maintaining the airport. The Air Force continued to use its own property and to
lease various parcels of land that were owned by Massport, all of which abutted the airfield.
Hanscom Air Force Base has become an important research and development facility in
Massachusetts. Although military operations at Hanscom have dropped to approximately one
percent of the aircraft activity, the airfield continues to be a valuable resource for the Base and
must be maintained at current and future military standards.
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Today, L. G. Hanscom Field plays an important role in New England's regional aviation system
by serving as a premier general aviation (GA) reliever for Logan International Airport. Hanscom
helps ease congestion at Logan by accommodating private, pilot training, business, charter, light
cargo, air taxi, medical, and military aircraft activity all of which serve the diverse flying needs
of government entities, corporations and businesses, research and development firms, and
educational institutions, as well as individuals. This full service GA facility serves as a vital link
to domestic and international destinations for local companies. Additionally, commercial service
to select markets has been periodically available at Hanscom in aircraft with no more than 60
seats, consistent with Massport's 1980 General Rules and Regulations for Lawrence G. Hanscom
Field.
On -going improvements of infrastructure and procedures ensure that Hanscom is a well -
equipped, safe, and secure facility for serving the diverse needs of its users, while standing ready
to support the future economic growth of the region. Massport recognizes the interest that the
residential and aviation communities have in its planning and operation "of the airport and has a
long history of sharing information with interested parties. Massport is committed to continuing
its relationship with the Hanscom Field Advisory Commission (HFAC), a committee consisting
of representatives from the surrounding communities, area -wide organizations, airport users, and
Ex Officio members from the FAA, Hanscom Air Force Base, and Minute Man National
Historical Park. The annual noise report is presented to HFAC each year.
CHAPTER 1 SUMMARY
The first noise report for L.G. Hanscom Field was prepared in 1982, and it compared data for
1978 and 1981. Annual updates were started in 1984 (based on the previous year's data), making
this the thirtieth Hanscom noise report. Starting with the first report, 1978 has been used as the
base year for evaluating changes in noise exposure. Chapters 2 and 6 review how this has been
done, despite updates in the noise and performance data used to calculate noise exposure at
Hanscom Field. This compilation of data provides a long term historical perspective on the
airport's aircraft activity.
The annual reports focus on the noise generated by civilian aircraft departures, including single
engine piston aircraft. This approach was an outgrowth of input from aviation and residential
representatives as the early noise reports were being developed. EXP, a metric that estimates
cumulative noise exposure at Hanscom, is used as the screening tool to evaluate the changes in
noise levels. This report presents the supporting data for calculating EXP, including total
numbers of operations and fleet mix by time of day. It also discusses noise levels for military
operations and arrival noise levels, and it includes data from the permanent noise monitoring
system for 1995, 2000, 2005, 2010 and 2011.
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Massport's data management systems compile information from a number of sources and include
estimates and formulas to develop the operations and noise data discussed in this report. Results
of this evaluation show the following:
1. The 2011 Federal Aviation Administration (FAA) Tower count, which includes all
arrivals and departures for both civilian and military aircraft activity between 7 a.m.
and 11 p.m., shows 162,999 operations, 0.5 percent fewer than in 2010.
2. While military flights represented approximately one percent of the total activity, they
contributed 33 percent of the total departure noise exposure. Tower counts indicate
that military operations decreased 21 percent in 2011, as compared to 2010.
3. The civilian portion of the FAA tower counts, which has consistently represented
approximately 99 percent of the total activity during the study years, decreased 0.2
percent as compared to 2010. Data indicate increases in all civilian aircraft categories
with the exception of Local (touch & go). Civilian activity contributed 67 percent of
the departure noise exposure.
4. The estimated 159.4 average daily single engine piston (SEP) departures, including
touch and goes, represented 71.4 percent of the 2011 operations and indicate a two
percent decrease in SEP activity as compared to 2010.
5. Non - single engine piston (non -SEP) civilian aircraft, which dominate changes in
civilian noise levels, averaged 60.2 daily departures in 2011. This represented a 4.6
percent increase in activity, as compared to 2010.
6. Business jet activity, which represented 17 percent of the total activity, increased two
percent in 2011 and contributed 86.7 percent of the civilian departure noise. Despite
the decrease in Stage 2 jet operations (the noisiest civilian aircraft) from 11 percent of
the jet fleet in 2000 to 1.1 percent in 2011, Stage 2 jets contributed over 13 percent of
the civilian jet departure noise in 2011.
7. Turboprop operations, which represented 4.2 percent of the total 2011 activity,
increased 20.7 percent.
8. Use of the airfield between 11 p.m. and 7 a.m. decreased from 1,832 arrivals and
departures in 2010 to 1,828 arrivals and departures in 2011. Jets (67 percent) and .
helicopters (15 percent) dominated this nighttime activity. A nighttime field use fee
was instituted in 1980 to discourage use of the field during these hours. Of the 741
different aircraft that were subject to the fee in 2011, 48 conducted more than five
operations. There were 326 operations exempt from the fee, of which 99.1 percent
were medical flights. Helicopters were used for the majority of the medical flights.
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9. Using EXP Version 6.1, the 2011 departure noise exposure for civilian aircraft was
109.1 decibels (dB), which represents a decrease of 0.1 dB compared to 2010.
Civilian departure EXP levels since 1978 indicate that noise exposure in 2011 is the
lowest of all the study years -to -date.
lo. This report includes a comparison of 1995, 2000, 2005, 2010 and 2011 noise levels
recorded at six noise - monitoring sites located in the communities and on the airfield.
The reported noise levels include civilian and military aircraft noise as well as
community noise. Changes in noise levels at the sites, based on available data, range
from a 0.1 dB increase to a 0.9 dB decrease when comparing 2011 to 2010.
11. In addition to the data analyses, this report discusses policies that have impacted noise
levels at Hanscom during the study years. The 1978 Hanscom Field Master Plan and
Environmental Impact Statement (The Master Plan) and the 1980 General Rules and
Regulations for Lawrence G. Hanscom Field include the policies and regulations that
continue to guide Massport as it operates Hanscom Field. Since the adoption of these
documents, Massport has worked closely with the HFAC and the Hanscom Area
Towns Committee (HATS), as well as other interested parties, to balance its
commitment to regional transportation and the business community with the need to
recognize and minimize the airport's impact on the surrounding communities.
Concepts for a new initiative to reduce touch and go traffic over Minute Man National
Historical Park have resulted in an average of 21 percent fewer flights over the Park
since the inception of the program in 2009.
CHAPTER 2 HISTORICAL PERSPECTIVE ON THE ANNUAL
REPORT AND THE EVALUATION OF NOISE
This chapter of the report discusses the development of measures used to evaluate noise exposure
at Hanscom. Each step was discussed with the HFAC, and the current approach was adopted
through general consensus at the HFAC meetings.
The first noise report was prepared in 1982 by Harris Miller Miller & Hanson Inc. (FIN4MH),
noise consultants for Massport, to evaluate the effectiveness of the noise rules that Massport had
implemented in 1980. The firm continued to prepare noise reports until 1987, when Massport
assumed the responsibility. In preparing the annual document, Massport utilizes the basic
approach and format of the original BA/1M H reports and includes some background information
written by H1 /1MR. Each year, Massport has a noise consultant review the noise data and annual
report. FFvRV1H reviewed the data and report for 2011.
2.1 The Use of Contours to Evaluate Noise Exposure
The most frequently used measure to characterize noise exposure around an airport is referred to
as the Day -Night Average Sound Level (DNL or Ldn), which is most commonly depicted by
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using contours on a map to connect points of equal noise exposure. Creating DNL contours
requires detailed knowledge of the fleet of aircraft using the airport, the types of aircraft engines,
the climb performance characteristics, information on the frequency of runway use, and the flight
paths of the aircraft as they depart and approach the field. These data are entered into. a computer
noise model to produce the contours.
DNL is used widely throughout the United States and is the metric used by the FAA for
assessing noise impacts. DNL is discussed in more depth in Appendix A. Appendix A also
includes maps from previous studies showing the 1978, 1987, 1995; 2000, and 2005 DNL
contours for Hanscom. The 1978 contours were developed in 1981 using the computerized
modeling program called Noisemap; the 1987 contours were developed in 1988 using the
Integrated Noise Model (INM) 3.9; the 1995 contours were developed in 1996 using INM 5.0;
the 2000 contours were developed in 2002 using INM 6.0c; and the 2005 contours were
developed in 2006 using INM 6.1. The contours include the effects of civil and military aircraft
as well as touch - and -goes. Touch and goes are a procedure used by flight schools to train
students to land and depart.
Time Above is another metric sometimes used to describe the noise experience by reporting the
amount of time that noise levels exceed a given threshold. Time Above is described in Appendix
A, which includes the 2000 and 2005 Time Above contours.
2.2 Developing EXP to Evaluate Changes in Noise Exposure
In addition to creating DNL contours, FRv1MH used the 1982 report to define a screening
procedure, or metric, that could be used to routinely evaluate the effect of changes in the aircraft
fleet mix and numbers of operations. A database management system was developed to
calculate the metric (called EXP), which has been used since 1982 as a first -round screening
procedure.
Although EXP does not show how noise levels change in specific communities, it does provide a
tool for distinguishing civilian noise from military noise while indicating changes in the total
noise exposure and expected changes in DNL. This is accomplished by having EXP use the
same FAA noise data for the aircraft types, and the same manner of logarithmically summing
noise used in calculating DNL, as discussed in Appendix A. This includes applying a "noise
penalty" of 10 decibels for each 10 p.m. to 7 a.m. aircraft event to account for its more intrusive
nature.
Each aircraft type is assigned to a group, with each group characterized by a similarity of size,
the number and type of engine(s), climb performance, and ultimately, noise level characteristics.
Using FAA noise and performance data, arrival and departure Sound Exposure Levels (SEL) are
assigned to each group. The SELs used for EXP are in A- weighted decibels and represent the
amount of noise generated 15,000 feet from start of take -off roll. There is additional discussion
of SEL in Appendix A.
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The total departure noise exposure on an average day is calculated for each group by:
1. Logarithmically multiplying the representative SEL for the group by the average number
of daily departures by those aircraft, applying the "noise penalty" to 10 p.m. to 7 a.m.
operations, and creating a "partial" departure EXP; and
2. Logarithmically adding all "partial" EXPs for the entire fleet to obtain, a single number
estimate of departure noise exposure.
2.3 The Significance of Changes in EXP
Because EXP applies the same methodology used for calculating DNL, it continues to be used as
a first round procedure to estimate changes in noise levels at Hanscom. In the mid- 1980s, HFAC
and Massport discussed the significance of changes in EXP, and it was agreed that an increase of
1.5 dB above the 1978 base year noise level would indicate the need for further study.
Although civilian departure EXP has never exceeded the 1978 EXP by 1.5 dB, Massport
completed a Generic Environmental Impact Report (GEIR) based on 1985 data, an update of the
GEIR based on 1995 data, an Environmental Status and Planning Report (ESPR) based on 2000
data, and an ESPR update based on 2005 data. The GEIRs and ESPRs include noise contours
and additional noise metrics, providing comprehensive analyses of noise impacts. Furthermore,
it is anticipated that updates of the ESPR, with detailed noise analyses, will continue to be
produced. The next scheduled ESPR will be based on 2012 data.
It is increasingly complex to compare current noise levels to noise levels from 25 years ago
because the FAA routinely updates the Integrated Noise Model, which is the basis of calculating
EXP. However, EXP still allows for an annual evaluation of changes in the noise level from one
year to the next and identifies trends in those changes.
2.4 Upgrading EXP Calculations
Until 1987, the EXP calculations relied primarily on SELs from the U.S Air Force's Noisemap
noise and performance database, which was available in 1982 when EXP was developed. In
1987, the FAA released a revised and expanded set of noise and performance data (Version 3.9)
for the Integrated Noise Model (INM), and Massport moved from using Noisemap to the INM.
The FAA continues to support a process of updating its aircraft noise and performance data for
modeling aircraft noise using the INM. As a result, Massport has periodically upgraded the SEL
values used in EXP. From 1987 through 1995, EXP Version 3.9 (EXP 3.9) was used. EXP
Version 5.1 (EXP 5.1) was used starting in 1996. EXP Version 6.Oc (EXP 6.0c) was introduced
in the 2002 report for the years starting in 2000, and EXP Version 6.1 (EXP 6.1) was introduced
in the 2005 report. The numbers in each version link to the RS TM version that was used.
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2.5 EXP Focus: With Single Engine Piston (SEP) vs. Without SEP,
With Military Aircraft vs. Without Military Aircraft, Departure EXP vs.
Arrival EXP
When EXP was first developed, it was calculated for civilian and military non -SEP aircraft
departures with the capability of using either subgroup for comparisons. SEP operations were
excluded from the data for reasons discussed in detail in early reports. When residents became
interested in the effect of the noise generated by these small aircraft, a method for estimating
their usage was developed for future use and was applied to all the study years retroactively.
In 1988, HFAC members discussed the need to focus on one number when comparing EXP from
one year to the next. It was agreed that the emphasis should be on civilian aircraft, and the
civilian component should include the estimated SEP operations. It was also agreed that
Massport would begin to track arrival EXP. However, the focus on departures would still be
used as the best representation of the noise impact because changes in departure EXP more
closely reflect changes in DNL than changes in arrival or total EXP.
2.6 The Report on 2011 Noise Exposure
This report incorporates the results of the agreed -upon methodology for evaluating the noise
impact, as it applies to 2011 Hanscom operations. It includes operational data for the study years
(1978, 1981 and 1983 through 2011) and analyzes the change in noise exposure since 1978. It
focuses on the effect of civilian aircraft departures, including SEP, with supplementary
information on FAA tower counts, 11 p.m. to 7 a.m. operations, the. impact of military activity,
and arrival EXP.
In addition to being considered a good indicator of changes in DNL and changes in the general
level of total noise exposure generated by the airport, it also provides a historical perspective,
because comparative data are available for most years since 1978. Data from the permanent
noise monitoring system became available during the 1990s, providing information on the
measured noise experience at six locations.
Methods of data collection for determining operations and noise exposure are reviewed in
Chapter 3 of this report. A discussion of the 7 a.m. to 11 p.m. operational levels for 2011 is
presented in Chapter 4. Chapter 5 focuses on operations conducted between 11 p.m. and 7 a.m.
when a nighttime field use fee is in effect. Chapter 6 presents noise exposure levels (using the
EXP noise metric), and Chapter 7 discusses the permanent noise monitoring system and the data
generated by the system. Massport policies that address aircraft noise are reviewed in Chapter 8.
MASSACHUSETTS PORT AUTHORITY
CHAPTER 3 DATA COLLECTION FOR DETERMINING
OPERATIONS AND NOISE EXPOSURE
Page
Hanscom Field serves various categories of civilian and military aircraft, and data are compiled
to track their noise impact. Input to the files used to develop operations and noise data come from
several sources, which are listed below.
Massport strives to use the best available data sources to track aircraft operations at Hanscom
Field. With recent upgrades to the Noise and Operations Monitoring System (MOMS), Massport
decided to leverage the database of aircraft operations within the NOMS as the main source data
for tracking operations at Hanscom Field. 2011 represents a transition year in this process.
FAA flight strips were used from January to September. Data from the NOMS were used for
October through December and will be used in subsequent years. A two month side -by -side test
showed excellent agreement between the final operations obtained using the two methods.
Sources of Data:
1. FAA Flight Strips: used to record non -SEP Instrument Flight Rule (IFR) departures from
Hanscom between 7 a.m. and 10 p.m. and all IFR arrivals and departures between 10 p.m.
and 11 p.m.
Pilots fly using either IFR or Visual Flight Rule (VFR) procedures. When flying IFR, a
flight plan is filed with the FAA, resulting in a flight strip identifying the aircraft type and
time of the operation at the origin and destination FAA towers. When there is VFR
weather, pilots may choose to fly without filing a flight plan. The majority of jets fly
IFR, regardless of the weather. Many turboprops and twins also fly IFR.
2. Noise and Operations Monitoring System (MOMS): provides arrivals and departures to
and from Hanscom at all times of day. Radar flight tracks record the exact times of
arrival and departure. Identifying information for the aircraft, such as the operator and
aircraft type, are matched to each flight using data from the aircraft's transponder and
electronic FAA flight plan and registration databases. Aircraft in the NOMS database
without identifying information, such as some VFR flights, cannot be used.
3. FAA Monthly Tower Reports: used to provide the number of aircraft operations at
Hanscom Field between 7 a.m. and 11 p.m.
The Hanscom FAA tower personnel maintain a count of all aircraft that operate at
Hanscom when the tower is open. This includes VFR and IFR arrivals and departures.
Prior to 1993, it also included aircraft that flew through the Hanscom air space (over
flights) but did not use the airport. The FAA tower count is traditionally used to quantify
the activity level for the airport, despite the exclusion of operations between 11 p.m. and
7 a.m. when the FAA tower is closed and the previous inclusion of over flights.
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4. Estimates of Civilian. VFR non -SEP Aircraft: used to supplement IFR activity by civilian
twin- engine pistons (twins), turboprops (turbos), and helicopters between 7 a.m. and 10
p.m.
Pilots of some turboprops and twin- engine aircraft and most helicopters fly VFR. They
communicate with the FAA tower, and the tower tallies the operation, although there is
no written record of the aircraft type or specific time of the operation. Estimates are
incorporated into the database programs to provide a reasonable representation of the
noise generated by civilian non -SEP VFR operations between 7 a.m. and 10 p.m.
5. An Estimate of Civilian SEP Activity between 7 a.m. and 10 p.m.
The number of civilian SEP aircraft operations is estimated by subtracting the civilian
IFR and estimated flights for jets, helicopters, twins, and turbos from the Tower counts
for non - military operations. Prior to 1993, the FAA Tower counts included all
communications with aircraft that flew through the Hanscom air space, whether or not
they used Hanscom, making the estimated number of SEP operations derived by this
method conservatively high. Starting in 1993, the approximations are closer to the actual
number of arrivals and departures since over flights are no longer included.
6. Nighttime Field Use Logs: Massport records all operations between the hours of 11:00
p.m. and 7:00 a.m. when the FAA tower is closed. These logs are used to supplement the
NOMS data.
TABLE 3.1 Data Sources for Civilian Aircraft (January — September 2011)
7 a.m.-10 p.m.
10 n.m: 11 P.M.
11 P.m.-7 a.m.
DEPARTURES:
FAA flight strips + an estimate for civilian VFR
Non -SEP
turbos, twins & helicopters
FAA flight strips
Massport records
FAA count for non - military operations minus civilian
SEP
non -SEP IFR & estimated VFR activity
FAA flight strips
Massport records
Difference between total departures &
ARRIVAL'S'
10 p.m. -7 a.m. arrivals
FAA flight strips
Massport records
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TABLE 3.2 Data Sources for Civilian Aircraft (October - December 2011)
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CHAPTER 4 2011 OPERATIONS, 7 a.m. -11 p.m.
As discussed in Chapter 3, the FAA tower counts are traditionally used to report the official
number of operations for an airport. At Hanscom, they include military operations and, until
1993, an unidentified percentage of over flights. During the study years, the Tower has not been
open from 11 p.m. to 7 a.m., so those counts do not include operations conducted between those
hours. Including night (11 p.m. to 7 a.m.) operations would increase the total by approximately
two percent. Night activity is discussed in Chapter 5.
Table 4.1 presents the Hanscom Tower counts since 1978, showing 162,999 operations for 2011.
This indicates a 0.5 percent decrease.as compared to 2010. For thirty years prior to 1993, the
Tower counts consistently exceeded 200,000, and in 1970 they peaked at more than 300,000.
They also exceeded 200,000 from 2000 through 2002. However, from 1993 through 1999, and
again from 2003 through 2011, tower counts have remained below 200,000.
7 a.m. -10 p.m.
10 L.M. -11 p.m.
11 p.m. - 7 a.m.
NOMS + an estimate for civilian VFR turbos,
NOMS supplemented by
Non -SEP
twins & helicopters
NOMS
Massport records
NOMS + sufficient additional operations to
NOMS supplemented by
SEP
reach FAA count for total civilian activity
NOMS
Massport records
CHAPTER 4 2011 OPERATIONS, 7 a.m. -11 p.m.
As discussed in Chapter 3, the FAA tower counts are traditionally used to report the official
number of operations for an airport. At Hanscom, they include military operations and, until
1993, an unidentified percentage of over flights. During the study years, the Tower has not been
open from 11 p.m. to 7 a.m., so those counts do not include operations conducted between those
hours. Including night (11 p.m. to 7 a.m.) operations would increase the total by approximately
two percent. Night activity is discussed in Chapter 5.
Table 4.1 presents the Hanscom Tower counts since 1978, showing 162,999 operations for 2011.
This indicates a 0.5 percent decrease.as compared to 2010. For thirty years prior to 1993, the
Tower counts consistently exceeded 200,000, and in 1970 they peaked at more than 300,000.
They also exceeded 200,000 from 2000 through 2002. However, from 1993 through 1999, and
again from 2003 through 2011, tower counts have remained below 200,000.
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TABLE 4.1 Annual FAA Tower Counts for 7 a.m. to 11 p.m. Since 1978
Page 11
Year
TouverCount
.Year
.. T_owerCount
.. Year,,:
Tower Count
. Year
Tower Count:
19781
235,750
1987
239,154
1996
179,497
2005
169,955
1979
225,805
1988
228,725
1997
188,087
2006
172,457
1980
218,502
1989
238,340
1998
183,185
2007
165,907
1981
213,698
1990
232,678
1999
197,302
2008
165,889
1982
215,984
1991
213,637
2000
212,371
2009
149,911
1983
219,466
1992
203,755
2001
205,436
2010
163,737
1984
229,130
1993
196,138
2002
218,248
2011
162,999
1985
247,434
1994.
187,550
2003
194,885
1986
232,110
1995
190,282
2004
180,804
The tower counts in Table 4.1 have been plotted in Figure 4.1 to illustrate the annual fluctuations
and overall decline since 1978, including the high of 247,434 operations in 1985 and the low of
149,911 operations in 2009. Decreases in SEP operations have been the predominant influence
on Hanscom's general decline in activity.
FIGURE 4.1 Annual FAA Tower Counts for 7 a.m. toll p.m. Since 1978
300,000
250,000
N
C
200,000
i
Q. 150,000
O
100,000
C
C
< 50,000
0
1978 1981 1984 1987 1990 1993 1996 1999 2002 2006 2008 2011
The FAA maintains separate tallies for "local" (i.e. touch - and -go) operations and military
activity in its daily counts. A touch - and -go is the pattern used to practice landing and departing,
most frequently conducted by the flight schools. The aircraft is brought in for a landing,
continues on the runway for a departure, circles the field and repeats the procedure without
stopping. The FAA tower tallies each touch -and -go as two operations, since there is an arrival
and a departure.
MASSACHUSETTS PORT AUTHORITY
Page 12
Starting in 1987, Massport has combined the FAA tower counts with the data collected in
Hanscom's database system in order to estimate the breakdown of 7 a.m. to 11 p.m. civilian
activity by aircraft type for both IFR and VFR operations, as shown in Table 4.2.
Table 4.2 Annual Estimated Operations by Aircraft Type, 7 a.m. -11 P.M.
CIVILIAN x
MILITARY
TOTAL.
rt Local a,
(
Siri les'
Twm
:. Piston t .
4.
� _Turf'o
:# ;:Jet..
Hel
F
'..},
1987
72,999
134,461
5,309
6,443
10,034
7,294
2,613
239,153
1988
66,669
127,233
5,968
8,800
10,216
7,258
2,581
228,725
1989
72,067
132,368
5,697
8,767
9,656
7,294
2,491
238,340
1990
76,732
124,756
5,658
7,582
8,630
7,262
2,058
232,678
1991
80,805
102,478
5,476
6,666
8,368
6,942
2,902
213,637
1992
83,427
92,328
4,940
5,579
8,105
6,834
2,542
203,755
1993
85,872
82,756
4,489
4,571
8,838
6,811
2,801
196,138
1994
86,287
74,294
4,581
4,223
9,345
6,819
2,001
187,550
1995
861048
76,685
4,589
3,997
9,592
6,804
2,567
190,282
1996
76,735
74,872
4,536
4,250
10,390
6,915
1,799
179,497
1997
76,217
83,515
4,157
3,733
11,248
6,912
2,305
188,087
1998
681506
81,976
5,797
4,524
13,583
6,878
1,921
183,185
1999
73,483
88,137
5,426
5,697
16,108
6,885
1,566
197,302
2000
75,676
90,323
5,097
12,848
20,226
6,914
1,287
212,371
2001
72,605
84,803
4,858
13,580
22,839
5,499
1,252
205,436
2002
76,849
82,282
5,295
14,598
30,788
7,012
1,424
218,248
2003
71,696
70,912
4,750
9,057
30,352
6,978
1,142
194,887
2004
1 60,794
63,755
4,818
10,155
33,021
7,066
1,195
1501804
2005
58,535
57,894
4,265
9,008
32,345
7,004
904
169,955
2006
59,222
58,198
4,352
8,828
33,251
7,014
1,592
172,457
2007
56,731
51,776
4,196
10,355
34,522
6,889
1,438
165,907
2008
65,906
50,063
3,988
6,881
30,656
6,805
1,590
165,889
2009
60,263
46,478
3,963
5,588
25,482
6,830
1,307
149,911
2010
66,038
1 52,631
1 3,451
5,704
27,293
6,825
1,795
163=162,999 737
2011
60,268
56,059
3,542
6,886
27,838
6,987
1,419
MASSACHUSETTS PORT AUTHORITY Page 13
Comparing 2011 to 2010, the FAA tower count for military operations, which represented
approximately one percent of the activity in 2011, decreased 21 percent. The civilian portion of
the FAA tower counts, which has consistently represented approximately 99 percent of the total
activity during the study years, decreased 0.2 percent as compared to 2010. Data indicate
increases in all civilian aircraft categories with the exception of Local (touch & go).
The level of jet activity is particularly relevant because jets dominate the civilian noise exposure.
Business jet use has traditionally been impacted by the economic health of the area, as illustrated
in Table 4.2. Jet activity levels declined during the slow economic years around 1990. This was
followed by a steady increase starting in the mid -1990s through 2000 when the economy was
recovering and then flourishing. As the economy slumped in 2001, the year started with a
decline in jet operations.
The events of September 11, 2001 (9/11) created a new factor that impacted aircraft activity,
particularly business jet activity levels. Despite the economic downturn, there was a surge in
business jet use after 9/11 as businesses began reevaluating the use of commercial airlines for
their travel needs. This resulted in a net increase in business jet use in 2001 and an additional 34
percent increase in 2002. Jet use continued to climb from 30,788 in 2002 to 34,522 in 2007,
when jets represented 2 1. 0 percent of Hanscom's total activity.
The economic recession that hit in 2008 caused business jet activity levels to decrease 11.2
percent in 2008 and 16.9 percent in 2009. In 2010, as the economy showed signs of a recovery,
business jet activity increased 7.1 percent. In 2011, jet activity increased 2 percent as compared
to 2010 and represented 17 percent of total activity.
There was also an increase in turboprop activity in 2011. Turboprop operations represented 4.2
percent of the 2011 total activity and increased 20.7 percent as compared to 2010.
Twin pistons and helicopters are the other non -SEP civilian aircraft that are tracked by Massport.
Estimated twin piston aircraft activity in 2011 increased 2.6 percent as compared to 2010, and
represented 2.2 percent of the operations. Estimated helicopter activity in 2011 increased 2.4
percent as compared to 2010, and represented 4.3 percent of the operations.
SEP aircraft have always dominated aircraft activity at Hanscom. SEP operations include
touch - and -go, local activity, which peaked in 1978 when the FAA logged 94,641 touch -and-
goes. Touch - and -go operations are included in Massport's estimates for single engine piston
aircraft activity for two reasons: 1) since 1980, touch - and -goes have not been allowed in aircraft
over 12,500 pounds at Hanscom, and 2) they are mostly conducted by the Hanscom flight
schools using SEP aircraft. In recent years, touch -and -go operations have represented 50 to 60
percent of the SEP activity.
In 2011, estimated SEP activity, including touch - and -goes, represented 71.4 percent of the
operations and decreased two percent as compared to 2010. Table 4.3 shows the estimated
average daily departures for SEP aircraft between 7 a.m. and 11 p.m. for the study years.
MASSACHUSETTS PORT AUTHORITY
Page 14
The 159.4 estimated average daily departures in 2011 represented a decrease of two percent as
compared to 2010. The highest study year for SEP activity was 1985, with 297.3 estimated
7 a.m. to 11 p.m. average daily departures.
TABLE 4.3 Estimated Average Daily Departures *, 7am - llpm by SEP Aircraft
Year SEP Departures
Year
SEP Departures
r
Year ,SEP Departures
Year '
SEP Departures
�r.
1978
282.0
1989
280.1
1997
218.9
2005
159.6
1981
242.6
1990
276.0
1998
206.2
2006
160.8
1983
258.0
1991
251.1
1999
221.6
2007
148.6
1984
270.4
1992
240.2
2000
227.0
2008
158.4
1985
297.3
1993
231.1
2001
213.7
2009
146.2
1986
278.4
1994
219.8
2002
219.8
2010
162.6
1987
284.2
1995
223.0
2003
195.5
2011
159.4
1988
264.9
1996
207.2
2004
170.2
Jul
51.07
*Estimated Average Daily Departures = Total Annual Operations from FAA tower counts divided by two,
minus the daily departures of aircraft other than single engine piston aircraft divided by 365 days (366 leap yr)
While the tower counts, along with the influence of the SEP operations on those counts, provide
one perspective on Hanscom's activity levels, it is the non -SEP operations, particularly the jets,
that are the major source of changes in noise levels. Table 4.4 shows a summary of the 2011
estimated average daily departures by non -SEP aircraft. These non -SEP departures have been
separated by day and 10 p.m. to 7 a.m. hours, which are the blocks of time used in noise
exposure calculations for DNL and EXP, both of which are discussed in Appendix A. The
average daily departures are for the identified and estimated civilian aircraft and the identified
military aircraft. They are listed month -by -month to show seasonal variations in activity.
TABLE 4.4 2011 Monthly Average Daily Departures by Non - Single Engine Piston Aircraft
AY r
GNILIAN "
. -iOpm -7am
x *_
?OTALr
.,
;,;DAY,
MILITARY
b10pm -7am TOTAL
§ CNILIAN &'MILITARY
'..tDAY .10pm -7am,
TOTALS;
Jan
49.62
2.81
52.43
"0.68
0.00
0.68
50.30
2.81
53.11
Feb
55.55
3.50
59.05
'0.46
0.00
0.46
56.01
3.50
59.51
Mar
57.98
3.19
61.17
0.71
0.00
0.71
58.69
3.19
61.88
Apr
62.37
2.90
65.27
0.60
0.00'.-
0.60
62.97
2.90
1 65.87
Ma
65.56
3.42
68.98
1.10
0.03
1.13
66.66
3.45
70.11
Jun
62.87
2.74 ' !
65.61
0.80
0.00 '!
0.80
63.67
2.74
66.41
Jul
51.07
2.35
53.42
0.58
0.00:'
0.58
51.65
2.35
54.00
Au
55.14
2.45:., !. !
57.59
1.00
0.03 !
1.03
56.14
2.48
58.62
Se
61:63
187
64.50
0.67 !
0.00
0.67
62.30
2.87
65.17
Oct
59:98
2.64
62.62
0.42
0.00 ! "
0.42
60.40
2.64
63.04
Nov
59.97
2.96
62.93
0.43
0.00::
0.43
60.40
2.96.
63.36
Dec
51:04
1.26 ''
52.30
`0.77
0.00; !
0.77
51.81
1.26
53.07
20'11 ,,,_
x_, 57.44 =.
2 72 �:
60.16 , .
_0 68 ..
0.00.
0 .fi8,
.:5812,x
'2.72
MASSACHUSETTS PORT AUTHORITY Page 15
The data show that the busiest month for civilian non -SEP activity was May, which averaged
68.98 daily departures, while the low occurred in December with 52.30 daily civilian non -SEP
departures. The civilian non -SEP activity averaged 60.16 daily departures during the year. The
identified military operations peaked in May with 1. 13 average daily departures. The lowest
military level was in October with 0.42 average daily departures. Military non -SEP activity
averaged 0.68 daily departures in 2011.
Figure 4.2 shows a plot of the data in Table 4.4, demonstrating the monthly variability of non -SEP
departures for both civilian and military activity. It is difficult to distinguish the civilian levels
from the combined total for civilian and military activity because of the civilian aircraft
dominance. The combined civilian and military level peaked in May, with 70.11 average daily
departures. The slowest month was December, with 53.07 average daily departures. Civilian and
military non -SEP activity averaged 60.84 departures during the year.
FIGURE 4.2 Monthly Average Daily Departures by Non -SEP Aircraft, 2011
80
N
v 70
i 60
CL 50 W' Civil
40 Military
30 t All
20
10
L
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Figure 4.2 reflects the influence of the seasons on non -SEP activity, showing peak activity levels
during the spring and fall and a decline during the summer. The spring and fall peaks are
common, although this is in contrast to the 2008 experience when there was a decline in the
summer without a fall recovery, an influence of the late 2008 downturn in the economy.
Table 4.5 shows the comparison of the 2011 data for non -SEP activity to previous study year
totals. The 60.16 average daily civilian departures are 2.9 percent more than in 2010. Non -SEP
civilian activity peaked in 2002 with 79.96 average daily departures.
MASSACHUSETTS PORT AUTHORITY
TABLE 4.5 Annual Average Daily Departures by Non -SEP Aircraft for Study Years
Page 16
Figure 43 plots the annual non -SEP departure activity for the study years from 1978 through
2011, demonstrating the dominance of the civilian activity over the past 30 years. It shows that
the non -SEP activity levels remained relatively stable between 1978 and 1998 and then increased
to a peak in 2002 with 81.65 average daily civilian and military departures.
CIVILIAN ; , ..., '
MILITARY `=
': CIVILIAN I MILITARY
M .
DAY, `.
10pii7am
.TOTAL' `
.DAY .
10pm -lam
;TOTAL
_'DAY,.. r
`ldpm -lam
''.TOTAL`'.
1978
35.55
2.11
37.66
3.32
0.03
3.35
38.87
2.14
41.01
1981
45.77
1.44
47.25
3.24
0.04
3.28
49.01
1.48
50.49
1983
39.82
0.91
40.73
1.76
0.01
1.77
41.58
0.92
42.50
1984
40.63
1.72
42.35
1.12
0.01
1.13
41.75
1.73
43.48
1985
38.68 1
0.73
39.41
2.22
0.04
2.26
40.90
0.77
41.67
1986
37.02
0.67
37.70
1.81
0.03
1.84
38.83
0.69
39.52
1987
39.61
1.00
40.61
2.13
0.04
2.17
41.75
4.04
42.79
1988
43.67
1.73
45.40
2.15
0.08
2.23
45.82
1.83
47.65
1989
42.72
1.71
44.43
2.45
0.08
2.53
45.17 1
1.78
46.95
1990
39.61
1.16
40.77
1.77
0.06
1.83
41.38
1.22
42.60
1991
37.27
1.00
38.27
2.39
0.13
2.52
39.66
1.13
40.79
1992
34.48
1.03
35.51
2.24
0.06
2.30
36.72
1.09
37.81
1993
33.55
0.90
34.45
2.49
0.11
2.60
36.04
1.02
37.06
1994
33.99
0.92
34.91
2.12
0.08
2.20
36.10
1.01
37.11
1995
34.01
1.15
35.16
2.06
0.10
2.16
36.07
1.24
37.31
1996
35.25
1.70
36.95
1.74
0.09
1.83
36.99
1.79
38.78
1997
35.38
2.04
37.42
1.75
0.04
1 1.79
37.12
2.08
39.20
1998
41.71
2.05
43.76
2.08
0.11
2.19
43.79
2.16
45.95
1999
46.31
2.27
48.58
1.81
0.04
1.85
48.12
2.31
50.43
2000
60.83
2.91
63.74
1.35
0.06
1.41
62.18
2.97
65.15
2001
65.27
2.77
68.04
1.56
0.00
1.56
1 66.83
2.77
69.60 .
2002
76.50
3.46
79.96
1.66
0.03
1.69
78.16
3.49
81.65
2003
69.18
1 3.00
72.18
4.34
0.02
1.36
70.52
3.02
73.54
2004
72.01
3.47
75.48
1.30
0.01
1.31
73.31
3.48
76.79
2005
68.32
3.32
71.64
0.85
0.02
0.87
69.17
3.34
72.51
2006
68.52
4.24
72.76
0.80
0.02
0.82
69.32
4.26
73.58
2007
71.06
4.28
1 75.34
1.01
0.02
1.03
72.07
4.30
76.37
2008
61.00
3.19
64.19
0.89
0.02
0.91
61.89
3.21
65.10
2009
53.92
2.57
56.49
0.90
0.02
1 0.92
54.82
2.59
57.41
2010
55.65
2.84
58.49
0.78
0.03
0.81
56.43
2.87
59.30
2011
57.44
2.72
60.16
0.68
0.00
0.68
58.12
2.72
60.84
Figure 43 plots the annual non -SEP departure activity for the study years from 1978 through
2011, demonstrating the dominance of the civilian activity over the past 30 years. It shows that
the non -SEP activity levels remained relatively stable between 1978 and 1998 and then increased
to a peak in 2002 with 81.65 average daily civilian and military departures.
MASSACHUSETTS PORT AUTHORITY Page 17
FIGURE 4.3 Annual Variations in Average Daily Departures by Non -SEP Aircraft
2 90
80
70
EZ
° 60 - E— Civilian
60 - - o-- Milita
4 N
0
Q 30 — A, All
n) 20
co 10
o a,
4 1978 1984 1987 1990 1993 1996 1999 2002 2005 2008 2011
1979,1980, AND 1982 DATA UNAVAILABLE
Business jet and turboprop operations caused the post 1998 non -SEP increases. There were more
than 60 average daily non -SEP departures annually between 2000, the first full year after
commuter service was re- introduced at Hanscom in turboprop aircraft, and 2008, when the
commuter service was terminated. The peak year, 2002, was influenced by a 50 percent increase
in jet activity during the first twelve months after the events of September 11, 2001, plus it was
in 2002 that Hanscom experienced its highest number of commuter operations in turboprops.
The 2011 increase in non -SEP activity, as compared to 2010, resulted primarily from a modest
economic recovery after 2009.
CHAPTER 5 11 P.M. to 7 A.M. OPERATIONS
Hanscom Field is a public facility and is open for use 24 hours a day. However, aircraft using
the airport between 11 p.m. and 7 a.m. communicate with the FAA's Boston approach control
facility because the Hanscom FAA control tower is closed. Therefore, this activity is not
included in the Hanscom FAA tower counts discussed in Chapter 4.
In the summer of 1980, Massport instituted an 11 p.m, to 7 a.m. airfield use fee to help minimize
noise exposure by discouraging use of the field between 11 p.m. and 7 a.m. The fee is based on
aircraft weight and doubles for aircraft that conduct more than five night operations in a calendar
year. From 1980 until 1989 the fees were $20 for aircraft weighing 12,500 pounds or less and
$150 for aircraft weighing more than 12,500 pounds.
In 1988, there was a review of the nighttime field use fee. In 1989, the Massport Board voted to
increase the fees to reflect the Consumer Price Index (CPI) increase between 1980 and 1989 and
to institute an annual CPI increase, effective each July 1. In 2011, there was a 2.7 percent CPI
MASSACHUSETTS PORT AUTHORITY Page 18
increase so the 2011 fees increased from $53 to $55 for aircraft up to 12,500 pounds and from
$391 to $401 for aircraft over 12,500 pounds.
Records for activity between 11 p.m. and 7 a.m. were not maintained prior to the institution of
the night field use fee. Table 5.1 shows the history of these operations starting with 1981, the first
full year they were logged. Activity levels fluctuated in the early 1980s and then increased to
just over 1,000 in 1988 and 1989. In 1990, nighttime activity decreased and subsequently
remained below 1,000 annual operations through 1995, a likely reflection of the depressed
economy and the fee increases.
TABLE 5.1 11 p.m. to 7 a.m. Operations Since Nighttime Fee was Instituted
Year
,. , 14 °p.m:- 7a.m.:
Year,'
11 �p.m: -7
1981
585
1997
1,495
1982
532
1998
1,390
1983
640
1999
1,622
1984
759
2000
1,918
1985
442
2001
1,674
1986
466
2002
2,170
1987
850
2003
1,743
1988
1,098
2004
2,006
1989
1,053
2005
1,894
1990
773
2006
2,324
1991
797
2007
2,284
1992
702
2008
1,910
1993
689
2009
1,735
1994
735
2010
1,832
1995
919
2011
1,828
1996
1,159
NOTE: The above totals include aircraft operations that are exempt from the fee, with the exception of some missing
exemption figures in 1983 and 1984 and possibly in 1981 and 1982. Since exemptions for other years in the 1980s
represented a small number of nighttime operations, the totals in the table area are assumed to closely reflect the
number of night operations for each year.
Since 1996, the number of 11 p.m. to 7 a.m. operations has consistently exceeded 1,000, partially
due to night activity by medical air ambulance services, which transport critically ill or injured
patients. In 2011, there were 323 night air ambulance services, which is a 24 percent decrease
compared to 2010. Total night operations decreased from 1,832 in 2010 to 1,828 in 2011. All
categories increased with the exception of helicopters.
The data in Table 5.1 are plotted in Figure 5.1, illustrating the fluctuations in 11 p.m. to 7 a.m.
activity. They demonstrate that there has been a general upward trend that became more
pronounced after 1995. Since 1999 there have been fluctuations between a low of 1,622 in 1999
to a high of 2,324 in 2006. Four of those years exceeded 2,000 operations.
MASSACHUSETTS PORT AUTHORITY Page 19
FIGURE 5.1 Annual 11 p.m. to 7 a.m. Operations since Nighttime Fee was Instituted
2500
N
C
2000
n�
L
IN, :��4
CL 1500
1 1000
_2)
z
a-
500
0
z
a
1981 1984 1987 1990 1993 1996 1999 2002 2005 2008 2011
Table 5.2 provides an overview of the 2011 11 p.m. to 7 a.m. operations by aircraft type, arrivals
and departures, and significant flight times. It also shows a breakdown of the number of
operations by fee amount levied for each category of aircraft. Those aircraft being charged $110
or $802 conducted more than five operations in the calendar year.
TABLE 5.2 Breakdown of 201111 p.m. to 7 a.m. Operations
Of the 1,828 night operations, 326 were exempt. Medical flights, dominated by the medical
evacuation service based at Hanscom, represented 99.1 percent of the exemptions. Exemptions
also included operations by military aircraft and Hanscom -based aircraft that used the airport
between 11 p.m. and 7. a.m. due to unavoidable circumstances, such as weather, mechanical, or
FAA delays. There were 741 different aircraft that were subject to the nighttime fee. Of those,
48, or 6.5 percent, conducted more than five nighttime operations that were subject to the fee. 60
percent of the 11 p.m. to 7 a.m. operations were arrivals; 40 percent were departures. Over 25
percent of the night operations occurred between 6 a.m. and 7 a.m. while more than 26 percent
were between 11 p.m. and midnight. The remaining 49 percent were between midnight and 6
a.m.
TIME'O.F. OPERATION;,
:' F.EE:DISTRIBUT.ION1
s. :.
TOTAL
E,d
3z
£
1 PM-16
6 to 7
n
Ar:
Dep4{
$401
$802
Ezemp
.
, .
,.
. 12 AM ...,
AM,
OtFier
,. $55,.
$110
,
_
Jet
755
475
319
327
584
531
5
9081
215
49
!1,230
Piston
68
75
46
48
48
124
7
0
0
12,:;
' 143
Turbo
123
56
45'
31
1'03
130
13
22
0
14
179
Helis
1 1481
128
7511.
56
146
25
0
0
0
251
276'
TOTAL'
1 1,0941
734
485
462
881
332
25
930
215
326
': 11828
Of the 1,828 night operations, 326 were exempt. Medical flights, dominated by the medical
evacuation service based at Hanscom, represented 99.1 percent of the exemptions. Exemptions
also included operations by military aircraft and Hanscom -based aircraft that used the airport
between 11 p.m. and 7. a.m. due to unavoidable circumstances, such as weather, mechanical, or
FAA delays. There were 741 different aircraft that were subject to the nighttime fee. Of those,
48, or 6.5 percent, conducted more than five nighttime operations that were subject to the fee. 60
percent of the 11 p.m. to 7 a.m. operations were arrivals; 40 percent were departures. Over 25
percent of the night operations occurred between 6 a.m. and 7 a.m. while more than 26 percent
were between 11 p.m. and midnight. The remaining 49 percent were between midnight and 6
a.m.
MASSACHUSETTS PORT AUTHORITY
Page 20
Jets conducted the largest number of night operations by a single aircraft category, representing
67 percent of the activity. Helicopters represented 15 percent, turboprops 10 percent and pistons
represented eight percent of the night activity.
CHAPTER 6 NOISE EXPOSURE LEVELS
As discussed in Chapter 2, the 1982 HMMH noise study defined a screening metric, referred to
as EXP, to use in evaluating changes in noise exposure without resorting to complex noise
exposure contours for each application. It is the logarithmic sum, in decibels (dB), of the total
aircraft noise on an average day for the aircraft that used Hanscom. The estimate is made for a
point on the ground 15,000 feet from brake release for departures. A "noise penalty" of 10 dB is
applied to operations between 10 p.m. and 7 a.m. to be consistent with the development of DNL
noise contours.
6.1 2011 EXP Version 6.1
Noise exposure, represented by the EXP metric, is calculated monthly and annually at Hanscom.
As discussed in Section 2.4, EXP version 6.1 (EXP 6.1) is currently being used to calculate noise
exposure.
Table 6.1 presents the monthly departure EXP 6.1 values, including the effects of SEP aircraft, for
2011. Those portions of the noise attributable to civilian and military aircraft are separated in the
table to show the relative contributions of each.
TABLE 6.1 2011 Monthly Variations in Departure EXP 6.1
<i 14
�` Mopp. nth..,
Ewe -� .i.� �4 S �i :
��. EXP61cwith :SEPAIRCRAFT�G.f,.�:��
Civilian &,1Vlilitary
_ .
�.
Jan.
109.6
92:1
109.7
Feb.
110.1
91.8
110.1
Mar.
109.3
105:3
110:8
Apr.
109.2
105,5
110:7
May
109.6
110.0
112.8
Jun.
109.T:.,!-,
110.8
113:0
J ul.
108.2
107.0
110.6
Aug.
108.5
109' 7
112.1
Sep.
110.2
105:7
111.5
Oct.
108.6
93:7
1 08.7
Nov.
108.8
89.6
108:9
Dec.
107.5
87-8:
107.6
MASSACHUSETTS PORT AUTHORITY Page 21
Civilian departure EXP for 2011 was 109.1 dB, 67 percent of Hanscom's total (civilian and
military) departure noise energy. It fluctuated between a low of 107.5 dB in December and a
high of 110.2 dB in September. The low and high in EXP levels frequently do not correlate with
the low and high for non -SEP activity levels. Although non -SEP activity dominates noise
exposure, the high for civilian non -SEP activity, as seen in Table 4.4, occurred in May, while
September had the highest noise exposure. The low for non -SEP aircraft activity was December,
which does correlate with the low for noise exposure. This lack of correlation in May and
September is because EXP factors in the fleet mix and the nighttime "noise penalty ", not just the
numbers of operations.
Military EXP shows more variation in departure noise levels than the civilian portion. This
reflects the high noise levels of many military aircraft; a few operations by a particularly noisy
aircraft can cause EXP to increase significantly. Military aircraft are exempt from the noise
abatement measures that are applicable to civilian aircraft and have some of the highest SEL
values of any aircraft that use the airport. Military departure EXP totaled 106.0 dB in 2011, with
its lowest level in December and its highest level in June. The June high reflects activity by a
variety of military aircraft, from the KC135, which is equivalent to a Boeing 707, to a number of
fighter jets. Fighter jets have the highest SEL of all the aircraft types in EXP.
In 2011, military aircraft generated 33 percent of Hanscom's total noise energy despite
representing slightly less than one percent of the aircraft activity. Military activity has
consistently represented less than two percent of the activity during the study years, while its
contribution to the noise energy has ranged from 11 percent to 47 percent.
The departure EXP 6.1 data from Table 6.1 are plotted in Figure 6.1, which demonstrates that
military noise levels vary more than the civilian portions. The highest total (civilian and
military) EXP during the year was 113.0 in June, when the military level exceeded the civilian
portion. The lowest total departure noise exposure during the year was 107.6 dB in the month of
December.
FIGURE 6.1 2011 Monthly Averages in Departure Noise Exposure EXF 6.1
115
110 � -.... _
105 0 a
j 100 j'ft - ♦- civilian
T — �— Military
r —Civ. & Mil.
c 90O
0
85
X 80
W Jan. Mar. May Jul. Sep. Nov.
MASSACHUSETTS PORT AUTHORITY Page 22
Appendix B shows a detailed table of 2011 EXP 6.1. It includes the average daily departures and
arrivals as well as the departure and arrival SELs for each civilian and military aircraft group.
The aircraft types listed for each group are representative of those included in the group, and the
partial EXP specifies the noise impact for that group of aircraft. As explained in Chapter 2,
changes in departure EXP more closely reflect changes in DNL than do changes in arrival EXP,
so this report focuses on civilian departure EXP for primary comparative purposes. However,
arrival EXP is being calculated and is included in Appendix B.
Table 6.2 presents the decibel contribution of several aircraft categories to civilian departure EXP
6.1, illustrating the effect of civilian jets. Although civilian jets comprised 17 percent of the
civilian operations, they had the highest partial departure EXP and represented 79.6 percent of
the civilian departure noise energy. This reflects the relatively high SEL values assigned to
them. By contrast, single engine piston aircraft comprised 71.4 percent of the civilian activity
but contributed only 14.4 percent of the civilian departure noise energy. They have a relatively
low SEL but have the second highest partial EXP because of the large number of operations by
these aircraft.
TABLE 6.2 Contributions to Civilian Departure EXP for 2011 Operations
Partial EXP 6� 1
Aircraft Categoryt,y e ,. k
Contnbut�on to Clv�lian Departure_Noise Exposure
Jets 1.08.1 dB
Turboprops 89.6 dB
Helicopters 94.5 dB
Twin Engine Pistons 90.5 dB
Single Engine Pistons 100.7 dB
_r :;a!TOTALCIVILIAN EXP. :.1.09 1, dB
6.2 EXP Comparisons for Study Years, 1978 -2011
Massport has incorporated periodic upgrades of the noise and performance data used to produce
EXP. Because the importance of EXP is not in its specific value, but rather in the change in EXP
from one year to the next, methods have been developed to incorporate the upgrades while
presenting a reasonable representation of the changes in noise levels since 1978.
Table 6.3 shows civilian departure EXP for the study years from 1978 through 2001. It also
identifies the different EXP versions that were used and the changes in EXP for each year as
compared to the base year. Between 1978 and 1987, Noisemap was used to calculate the SEL
values for EXP. The results for the first year and the last year of that timeframe showed 112.5
dB for civilian aircraft departures. The resulting zero in the "Difference from Base Year"
column indicates equal civilian departure noise exposure, and this equal noise exposure allowed
MASSACHUSETTS PORT AUTHORITY Page 23
1987 to serve as an alternate base year for future comparisons. Applying EXP Version 3.9 to
1987 data showed EXP for civilian departures was 112.0 dB. From 1988 to 1995, EXP 3.9 was
calculated, and the difference from 112.0 dB indicated the year -to -year difference from the base
year.
TABLE 6.3 Civilian Departure EXP Comparisons, 1978 -2001
Annual" Base Year Difference ,.from
EXP l EXP, t, It : Base.Year -
r
Noisemap
1978
112.5
Original Base Year
1981
111.3
112.5
-1.2
1983
111.8
112.5
-0.7
1984
112.2
112.5
-0.3
1985
111.9
112.5
-0.6
1986
111.8
112.5
-0.7
1987
112.5
112.5
0.0
Version 3.9
1987
112.0
Alternate Base Year
1988
112.4
112.0
0.4
1989
111.6
112.0
-0.4
1990
110.8
112.0
-1.2
1991
110.7
112.0
-1.3
1992
111.4
112.0
-0.6
1993
110.6
112.0
-1.4
1994
111.4
112.0
-0.6
1995
111.6
112.0
-0.4
Version 5.1
1987
112.1
Alternate Base Year
1996
112.0
112.1
-0.1
1997
112.3
112.1
0.2
1998
113.1
112.1
1.0
1999
113.0
112.1
0.9
2000
113.4
112.1
1.3
2001
112.5
112.1
0.4
The 1996 transition to EXP 5.1 was facilitated by calculating the 1987 data using EXP 5.1. Table
6.3 shows the civilian departure EXP 5.1 for 1987 was 112.1 dB, and from 1996 to 2001 the
differences between EXP 5.1 for those years and EXP 5.1 for 1987 were calculated. Because
1987 noise levels had been determined to be equal to 1978 using Noisemap, this allowed for a
continued ability to represent the annual change in EXP as compared to 1978.
Past methodologies were not practical for the transition to EXP 6.Oc that occurred in 2000. EXP
5.1 was applied to the data for 2000 and 2001 but neither equaled EXP 5.1 in 1987, and there
was a risk in assuming that EXP 6.Oc SELs, which were developed for 2000 flying procedures
and aircraft, could be accurately applied to 15 year old data. Consequently,; it was determined
that EXP 5.1 and prior versions would illustrate the changes from 1978 to 2001 while future
versions would illustrate changes from 2000 forward.
EXP 6.Oc was used to track changes in noise between 2000 and 2005, as seen in Table 6.4. EXP
6.1 was introduced starting in 2005, and Table 6.4 shows civilian departure EXP 6.1 for the year
MASSACHUSETTS PORT AUTHORITY Page 24
2000, as well as for the years 2005 through 2011. As discussed in 2005 Noise Exposure Levels
at L. G. Hanscom Field, the differences in SEL levels for civilian aircraft groups between EXP
version 6.Oc and 6.1 were minimal. As a result, the annual civilian departure EXP was not
affected by the version that was used. This is demonstrated in Table 6.4 by the equal EXP level
for 2000, using Versions 6.Oc and 6.1 for both years, and again for 2005, using Versions 6.Oc and
6.1 for both years. Consequently, it is reasonable to compare the results of either version to the
other for the civilian component without further adjustments.
TABLE 6.4 Civilian Departure EXP Comparisons, 2000 -2011
y
An- d' ence from
f EXP; from 2000 from' 2001 Previous Year
� A 1 4 4 1
Version 5.1 2000
113.4
2001
112.5
-0.9
n/a
-0.9
Version 6.Oc 2000
112.3
2001
111.6
-0.7
n/a
-0.7
2002
112.4
0.1
0.8
0.8
2003
111.9
-0.4
0.3
-0.5
2004
111.9
-0.4
0.3
0.0
2005
111.4
-0.9
-0.2
-0.5
Version 6.1 2000
112.3
2005
111.4
-0.9
-0.2
-0.5
2006
111.0
-1.3
-0.6
-0.4
2007
111.3
-1.0
-0.3
0.3
2008
110.2
-2.1
-1.4
-1.1
2009
109.2
-3.1
-2.4
-1.0
2010
109.2
-3.1
-2.4
0.0
2011
109.1
=3.2
-2.5
-0.1
Because the upgrades in FAA noise data that are used to generate EXP make it difficult to make
a direct comparison of current noise levels to the 1978 noise experience, it has been determined
that identifying a range to represent the increase or decrease in civilian departure EXP is a
reasonable alternative. Table 6.3 shows a 0.4 dB increase in noise between 1978 and 2001, and
Table 6.4 shows a 2.5 dB decrease in noise between 2001 and 2011, indicating that civilian
departure EXP for 2011 is 2.1 dB less than 1978. Alternatively, Table 6.3 shows a 1.3 dB increase
in noise between 1978 and 2000, and Table 6.4 shows a 3.2 dB decrease between 2000 and 2011,
indicating that civilian departure EXP for 2011 is 1.9 dB less than 1978. In other words, 2011
civilian departure EXP ranges from 1.9 to 2.1 dB less than the noise exposure in 1978. A
comparison of 2011 civilian departure EXP with previous study years indicates that 2011
experienced the lowest noise levels of all the study years. The next lowest years were 2009 and
2010 with 2.0 dB below 1978.
MASSACHUSETTS PORT AUTHORITY Page 25
The EXP differences from the base year for the study years 1978 through 2001 shown in Table 6.3
are plotted in Figure 6.2 to demonstrate the way EXP changed through 2001. Figure 6.2 illustrates
a decrease in civilian departure EXP between 1978 and 1981, a subsequent general upward trend
through 1988, a decline in the early 1990s, and a consistent increase from 1993 through 1998.
From 1998 to 2001, EXP fluctuated at levels between 0.4 dB and 1.3 dB above the 1978 base
year. Figure 6.2 also demonstrates that until 2001, 2000 was the study year with the highest
civilian departure EXP, while 1993 was the lowest of those study years.
FIGURE 6.2 Differences Between Civilian Departure EXP for Study Years 1978 -2001
� 1.5
X
1
c`a
> 0.5
m0 Base Year Level
C3 a,
c Z= 0.5
ca
ri- o
X -1
w s
c
-2
1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
Note: 1979, 1980 and 1982 data unavailable
The EXP differences from 2000 for the study years 2001 through 2011, as shown in Table 6.4, are
plotted in Figure 6.3 to demonstrate the way EXP has changed since 2000. As in Figure 6.2, Figure
6.3 illustrates the decrease in EXP between 2000 and 2001. It also shows an increase in 2002,
when 2002 exceeded 2000 by a tenth of a decibel, making it the study year with the highest
civilian departure EXP to -date. This was followed by a general decrease in civilian departure
noise exposure to the lowest recorded level in 2011.
FIGURE 6.3 Differences Between Civilian Departure EXP for Study Years 2000 -2011
CD
0.5
CL -0.5
w -1.5
as -
-2.5
-3.5
2000 2001 2002 20032004 20052006 2007 2008 2008 2010 2011
MASSACHUSETTS PORT AUTHORITY
Page 26
Table 6.5 looks at the eight years for which EXP 6.1 was used to calculate EXP. It shows the
civilian and military components as well as the total noise exposure for both departures and
arrivals. Although all of this data is tracked, the noise report has never tried to analyze annual
changes in EXP for military aircraft, arrivals, or total activity. Rather, it focuses on changes in
the civilian portion for departures, which is highlighted in the table.
TABLE 6.5 EXP 6.1 Values for 2000 and 2005 through 2011
Version 6.1
CIVILIAN COMPONENT, WITH SINGLES
2000
112.3
dB
109.1 dB
2005
111.4
dB
108.8 dB
2006
111.0
dB
109.1 dB
2007
111.3
dB
109.3 dB
2008
110.2
dB
108.4 dB
2009
109.2
dB
- 107.9 dB
2010
109.2
- dB
108.0 dB
2011
109.1
dB
108.2 dB
MILITARY COMPONENT
2000
106.8
dB
99.0 dB
2005
108.4
dB
94.5 dB
2006
107.1
dB
94.2 dB
2007
109.9
dB
96.2 dB
2008
106.1
dB
95.1 dB
2009
107.2
dB
96.0 dB
2010
107.9
dB
95.9 dB
2011
106.0
dB
92.7 dB
TOTAL EXP (INCLUDING MILITARYAND SINGLES)
2000
113.4
dB
109.5 dB
2005
113.2
dB
109.0 dB
2006
112.5
dB
109.2 dB
2007
113.6
dB
109.5 dB
2008
111.6
dB
108.6 dB
2009
111.3
dB
108.2 dB
2010
111.6
dB
108.3 dB
2011
110.8
dB
108.3 dB
MASSACHUSETTS PORT AUTHORITY Page 27
6.3 Analysis of Changes in Annual EXP for Study Years, 1978 -2011
The fluctuations in civilian EXP over the past 32 years demonstrate three major influences on
noise exposure: 1) the number of jet operations, since jets dominate the noise exposure, as
discussed in Section 6.1; 2) whether the jet operations operated between 10:00 p.m. and 7:00
a.m. when the "noise penalty" is applied, as discussed in the introduction of this chapter and in
Appendix A; and 3) the amount of noise energy generated by each jet operation, which is
reflected in the SEL assigned each jet type, as discussed in Appendix A.
Because civilian departure EXP is dominated by jet activity, it is useful to look at the number of
operations conducted at Hanscom Field by the jets in each SEL group, and to see how they
compare to previous years.. Figure 6.4 shows the level of activity for each jet SEL group for 2000,
2005, 2010 and 2011. It demonstrates that most of the jet operations occurred in aircraft with
SELs of less than 94 dB. Included in these aircraft are the Very Light Jets, small, relatively
inexpensive aircraft with some of the smallest noise footprints of all the jets that use Hanscom.
FIGURE 6.4 Average Daily Jet Departures by SEL Groups, 2000, 2005, 2010 & 2011
Civilian Jets, 2000, 2005, 2010 & 2011
SEL Values from EXP Version 6.1
Representafne Jets
in each SEL Group
W
82.0 - Citation 750
82.1134
2 16
:3
14
83.0 - Eclipse 500
ca
Z
d) 12
84.6- Canadair 61
862- Glohal Ex, G3
p
86.7 - Canadair 60
10 i -
872 -8738
_
0 8 I
87.3- Citation 500
889- Citation 650
i
89.4-A320, A319
O 6 i
90.9- Westwind24
_
912 -BE40, Lear 55
Z 4 -
91.9- MI13,C550
Q
93A -Fait. 50 & 90
2
94A -DC9
N t _ _
95.4 -9737
-
96.9 -Fait 20,SBR -80
Q 820 83.0 86.2 87.0 88.8 90.9 91.2 93.0 95.6 95.9 97.2 103.8
96.7- Genencjet
972.63
SEL values in dBA
103.8-B727 51age3
1052- Lear23,SBR40
■ 2000 o2005 ■ 2010 m2011
The noise energy levels of the Hanscom fleet have been influenced by federal and Massport
regulations directed at reducing noise exposure for residents both nationally and around
Hanscom. The FAA first issued noise standards for civil aircraft in 1969, when regulations
established that minimum noise performance levels must be demonstrated for new turbojet and
transport category large airplane designs. In 1977, more stringent standards were adopted, and
Stage 1, 2, and 3 classifications were introduced. Stage 1 airplanes do not meet either the 1969
or 1977 standards. Stage 2 airplanes meet the 1969 standards but do not meet the 1977
standards. Stage 3 airplanes meet the 1977 standards.
MASSACHUSETTS PORT AUTHORITY Page 28
Over the years, the FAA also adopted regulations that phased out the use of Stage 1 and 2 aircraft
weighing more than 75,000 pounds. However, most jets using Hanscom weigh less than 75,000
pounds, so the impact was minimal.
In 1980, Massport adopted rules to address some of the noise issues being discussed with'the
communities around Hanscom. These rules included a phase out of Stage 1 civilian jet
operations in aircraft over 12,500 pounds, a fee to discourage 11 p.m. to 7 a.m. activity, and
restrictions on touch and. go operations. Figure 6.2 clearly demonstrates the initial impact of these
rules. The 1981 civilian departure EXP decreased 1.2 dB as compared to 1978, the only previous
study year. This initial decrease was followed by an upward trend in civilian departure EXP
caused by an overall increase in jet activity resulting from a strong economy. As discussed
earlier, by 1987 the noise exposure equaled 1978, and the 1988 exposure exceeded the base year
for the first time.
Between 1988 and 1993, the slow economy resulted in an overall decrease in civilian departure
EXP that was influenced by a decline in business jet operations, including fewer Stage 2 jets. In
1993, when civilian departure EXP dropped to the lowest level of all the 1978 to 1993 study
years, there were increases in business jet activity as compared to 1992, but Stage 2 jet
operations decreased.
From 1993 through 2000, EXP for civilian departures showed an upward trend caused by annual
increases in business jet operations. In most years, that included more Stage 2 jet activity and
more jet activity between 10:00 p.m. and 7:00 a.m. Although the number of Stage 2 jet
operations was increasing, the percentage of Stage 2 jets began to decrease during these years. In
1995, Stage 2 jets represented 18 percent of the jet fleet. By 2000, Stage 2 jet activity had
dropped to 11 percent of the jet operations.
Starting in 2000, natural attrition of Stage 2 aircraft translated into an overall decline in EXP.
The turnover from Stage 2 to Stage 3 aircraft helped counteract the noise generated by the overall
increases in business jet activity. However, there were two years (2002 and 2007) when civilian
departure EXP increased as compared to the previous year's noise level.
• In 2002, there were increases, as compared to 2001, in both Stage 2 and Stage 3 jet
activity during the daytime hours and between 10 p.m. and 7 a.m. when the nighttime
noise penalty is applied in the noise calculations. These increases reflected a reaction to
the events of September 11, 2001 that resulted in many businesses turning to private
aircraft rather than flying commercially. Thus, 2002 EXP increased as compared to 2001
and became the study year with the highest noise level to -date.
• In 2007, Stage 3 jet operations increased while Stage 2 jet activity decreased during the
nighttime and daytime hours. As a result, 2007 was the first year that an increase in noise
level was driven by increases in Stage 3 jet operations, which occurred during both the
daytime and nighttime hours. This experience provides a window to the future.
Assuming current trends continue, changes in noise levels at Hanscom will increasingly
reflect increases and decreases in the noisiest Stage 3 jet activity levels, coupled with the
fluctuations in jet activity during the nighttime hours.
MASSACHUSETTS PORT AUTHORITY Page 29
Although total jet activity increased 38 percent between 2000 and 2011, Stage 2 jets decreased
over 85 percent, and in 2011, they represented only 1.1 percent of the jet fleet. Figure 6.5
illustrates the 2000 through 2011 activity levels for the Stage 2 EXP jet groups. There were
decreases by all groups of Stage 2 aircraft in 2011 as compared to 2000.
FIGURE 6.5 Stage 2 Jet Activity, 2000 -2011
In 2011, Stage 2 jets comprised 11 percent of the total civilian noise energy for departures and 13
percent of the civilian jet noise energy for departures. In 2012, Congress passed the FAA
Modernization and Reform Act, which included the phase out of all non -stage 3 aircraft by
December 31, 2015. This mandatory federal phase out of Stage 2 jets that weigh less than 75,000
pounds will facilitate more rapid noise reduction at airports nationally. Massport's support of
this phase out is discussed in Chapter 8.
As discussed in Chapter 4, an important influence on jet activity levels is the economy.
Predictably, the positive economic trends of the mid to late 1980s and again in the mid to late
1990s and into 2000 resulted in increased business jet activity at Hanscom Field. Helping
counteract the noise generated by the increases in jet operations in the 1980s was the phase out of
most Stage 1 jets at Hanscom Field, and in the 1990s there was some turnover from Stage 2 to
Stage 3 jets as businesses upgraded their equipment. For jets over 75,000 pounds, the upgrades
were required nationally by the year 2000. To meet this mandate, some aircraft operators
upgraded to new Stage 3 aircraft while others installed hush kits that reduced the noise footprint
of a non -Stage 3 aircraft and brought it below the Stage 3 noise threshold.
Stage 2
Civilian Jets, 2000 -2011
SEL Values from EXP Version 6.1
1.2
d
5
1.0
`m
m
0.8
Representative Jets
❑
in each SE_ Group
95.9 - DA02
m
0.6
¢
95.9- SBR_80
❑
9Z2 -G3
99.6 - G2
°
0.4
s
105.2- Lear23,SBR-40
z
m
a
0.2
$
0.0
95.9
95.9 97.2 99.6 105.2
SEL values in dBA
02000 02001
■2002 02003 ■2004 02005 ®2006 02007 V2008 M2009 a2010 E2011
In 2011, Stage 2 jets comprised 11 percent of the total civilian noise energy for departures and 13
percent of the civilian jet noise energy for departures. In 2012, Congress passed the FAA
Modernization and Reform Act, which included the phase out of all non -stage 3 aircraft by
December 31, 2015. This mandatory federal phase out of Stage 2 jets that weigh less than 75,000
pounds will facilitate more rapid noise reduction at airports nationally. Massport's support of
this phase out is discussed in Chapter 8.
As discussed in Chapter 4, an important influence on jet activity levels is the economy.
Predictably, the positive economic trends of the mid to late 1980s and again in the mid to late
1990s and into 2000 resulted in increased business jet activity at Hanscom Field. Helping
counteract the noise generated by the increases in jet operations in the 1980s was the phase out of
most Stage 1 jets at Hanscom Field, and in the 1990s there was some turnover from Stage 2 to
Stage 3 jets as businesses upgraded their equipment. For jets over 75,000 pounds, the upgrades
were required nationally by the year 2000. To meet this mandate, some aircraft operators
upgraded to new Stage 3 aircraft while others installed hush kits that reduced the noise footprint
of a non -Stage 3 aircraft and brought it below the Stage 3 noise threshold.
MASSACHUSETTS PORT AUTHORITY Page 30
CHAPTER 7 NOISE MONITORING SYSTEM
In the late 1980s, Massport and the surrounding communities agreed that a permanent noise
monitoring system (NMS) could contribute to a more complete picture of the noise environment
around the airport by adding data to the existing EXP metric. EXP looks at total noise on an
average day, with a focus on civilian departure EXP, and doesn't consider runway use, for
example. In the early 1990s, five noise monitors were installed on and around the airport. A
sixth monitor was installed in late 1994. Data for all the monitor sites became available in 1995.
Given the age of Massport's original noise monitoring system and the advancement of
technology in this field, in 2004, Massport decided to upgrade its system. Massport requested
proposals and subsequently selected Rannoch Corporation; now ITT Exelis Corporation, to
replace the system's microphones and software. Hanscom staff members began experiencing the
benefits of the new system in 2007 and have been able to provide callers with more information
about disturbing flights than had been available in the past. An interactive website is being
developed.
The data from the monitors shown in this report are Day -Night Average Sound Levels (DNL) in
A- weighted decibels, both of which are described in Appendix A. These are actual measured
levels, so they include military and civilian aircraft as well as community noise.
In April of 2009, the Site 34 monitor on DeAngelo Drive in Bedford was hit by a vehicle, which
caused substantial damage. Because a tree that had grown near the site could potentially
contaminate data and because there had been similar incidents in prior years, Massport
determined that a new location needed to be identified for installing a replacement. This led to a
review of possible locations, which included discussions with Bedford representatives and taking
noise measurements and analyzing flight tracks at numerous alternative sites. It was determined
that DeAngelo Drive was the best acoustical location, which led to selecting a site that was close
to the old site but away from trees and set back from the road. This work was completed in
2010.
Table 7.1 shows the readings at the six sites for 1995, 2000, 2005, 2010 and 2011. Footnotes
identify the number of months included in the data. Appendix C shows the readings for those
years by month. Appendix C also includes a map showing the locations for the monitors. Data
for the years not included in this report can be found in previous annual noise reports, available
in Massport's offices.
MASSACHUSETTS PORT AUTHORITY Page 31
TABLE 7.1 Measured DNL Levels -1995, 2000, 2005, 2010 and 2011
Site No.
1995
2000
2005
2010
2011
31
67.2
66.5
68.3
66.9
66.3
32
66.7
64.5
64.1
63.6
63.7
33
57.1
55.7
56.1
56:1
55.2
34
60.1
59.7
60.6
60.7
60.1
35
60.5
60.2
59.2
60.2
59.8
36
62.4
62.8
62.3
61.8
61.9
A comparison of the 2010 and 2011 annual DNL values at six sites shows increases of 0.1 dB at
Site 36 (Concord) and Site 32, located at the approach end of Runway 29. Site 33 (Lincoln)
decreased 0.9 dB, Site 34 (Bedford) decreased 0.6 dB, Site 35 (Lexington) decreased 0.4 dB, and
Site 31, located at the approach end of Runway 11, decreased 0.6 dB.
The measured changes must be looked at carefully for both aviation and non - aviation influences.
Aviation influences include the noise levels generated by specific aircraft and runway use, which
determines which monitors are impacted by a particular flight.
Military aircraft activity can cause particularly high readings because of the high noise levels of
some military aircraft, such as fighter jets. Some months are influenced by military events that
result in increased military activity at Hanscom: an Air Force Air Show generated high noise
levels in June of 1995; in October of 1995, there was a test of navigational equipment, which
required a military KC135 (Boeing 707 equivalent) to conduct multiple low approaches over the
airport; fighter jets operated out of Hanscom in order to conduct fly -overs at special events,
including Red Sox games in April 2005 and April 2010, and Marine week in 2010. This military
activity is known to have contributed to the monitor readings in those years but is only partially
reflected in military EXP because only the military IFR events are accounted for in the computer
modeling.
Readings may also reflect non - aviation noise sources. In 1995, Sites 31 and 32 experienced
noise from the use of tree removal equipment. Construction noise influenced readings at Site 31
in 2005 and 2010. Site 36 is also influenced by noise from the near -by wastewater treatment
facility, which produces background noises that contribute to the readings. As a result, Site 36
consistently shows the highest recorded levels at an off - airport location.
The data in Table 7.1 are plotted in Figure 7.1, which demonstrates the fluctuations in measured
noise at the six sites for 1995, 2000, 2005, 2010 and 2011. Sites 31 and 32 consistently have the
highest readings because they are located on the airport at the ends of Runway 11/29. They are
the least likely to be influenced by consistent community noise and therefore are likely to have
the closest correlation to noise levels shown in noise contours.
MASSACHUSETTS PORT AUTHORITY Page 32
FIGURE 7.1 Measured DNL Values -1995, 2000, 2005, 2010 and 2011
70
65
Q
60
55
0 50
45
40
DNL Levels at Noise Monitor Sites
1995, 2000, 2005, 2010 and 2011
Site 31 Site 32 Site 33 Site 34 Site 35 Site 36
13'95 Woo 13'05 Elio ■111
Note: 2010 includes seven months of data at Site 34.
CHAPTER 8 NOISE ABATEMENT POLICIES
Site Locations
(See Appendix C for
map)
Site 31— Runwayl l
Site 32 — Runway 29
Site 33 — Lincoln
Site 34 — Bedford
Site 35 — Lexington
Site 36 — Concord
Massport operates Hanscom as a safe and secure, well- equipped, modern airport that serves the
diverse needs of its users and accomplishes its role in the regional transportation system, while
being sensitive to the concerns of the surrounding communities. Massport encourages
meaningful public participation and expends considerable resources in an attempt to strengthen
its relationship with its neighbors. Towards this effort, Massport strives to disseminate accurate
information on a timely basis, mitigates environmental impacts whenever and wherever possible,
and prepares in -depth environmental studies and/or analyses during its planning and project
review processes.
In 2009, Massport began a new initiative to reduce noise over the Minute Man National
Historical Park. Most touch and go operations circle to the south of the airport, potentially taking
the aircraft over areas of the Battle Road Trail that are used by the Park for outdoor programs and
interpretive talks. In a partnership with the Park, the FAA, the flight schools and Hanscom
pilots, it was determined that small aircraft could increase the use of a tight touch and go pattern
that keeps the aircraft over the airfield rather than over sensitive park areas.
MASSACHUSETTS PORT AUTHORITY Page 33
This touch and go initiative is the latest of many efforts to minimize aircraft noise that began
over 30 years ago. In 1978, the Massport Board adopted the Hanscom Field Master Plan and
Environmental Impact Statement (The Master Plan). This official policy statement regarding the
future development and management of Hanscom Field was developed by Massport staff in
conjunction with the Governor's Hanscom Field Task Force. The Task Force, which represented
neighboring towns, airport users, state legislators, public interest groups and other stakeholders,
was established to ensure that all concerns were considered in a plan that would guide
Massport's operation and maintenance of the airport.
The plan's 12 policy statements fall under four broad categories, as follows:
Growth:
1. The character of the airport
2. Airport activity and runway facilities
3. Certified passenger air carrier operations
4. Passenger commuter operations
5. Cargo operations
6. Airport improvements
7. Aircraft noise
Land use:
1. Aviation related land use
2. Other Massport properties
Ground access:
1. Ground access
Planning process:
1. Hanscom Field Advisory Committee
2. Airport System Planning
One outgrowth of The Master Plan was the formation of the HFAC. Another was the Massport
Board's adoption of the 1980 General Rules and Regulations for Lawrence G. Hanscom Field,
which was designed to address noise issues. The rules for Hanscom included phasing out the use
of most Stage 1 aircraft, limiting touch - and -go operations to aircraft under 12,500 pounds,
limiting touch -and -go activity to the hours of 7 a.m. to 11 p.m., limiting commercial air carrier
passenger service to aircraft with no more than 60 seats, and establishing the nighttime
field use fee. It also provided parameters for the use of Ground Power Units and updated the
definition of commuter aircraft that had been referenced in The Master Plan.
The Master Plan and the 1980 Rules (available in Massport offices) continue to guide Massport
for Hanscom related decisions. Massport continues its diligent enforcement of the rules, while
actively sharing data, plans, and policies with the aviation and residential communities.
Massport staff members participate at all HFAC meetings and attend Hanscom Area Towns
MASSACHUSETTS PORT AUTHORITY Page 34
Committee (HATS) meetings, as well as other forums where their presence is requested or seems
warranted.
Massport has also completed a series of environmental studies, which inform staff in planning
Hanscom's future and provide the communities with extensive data related to the airport,. as
follows: a Generic Environmental Impact Report (GEIR) based on 1985 activity levels, a GEIR
Update based on 1995 activity levels, an Environmental Status and Planning Report (ESPR)
based on 2000 activity levels, and an ESPR based on 2005 activity levels. The Secretary of
Environmental Affairs found all of these documents to adequately comply with the
Massachusetts Environmental Policy Act (MEPA). Massport is currently gathering data for the
next ESPR, which will be based on 2012 data.
The GEIR/ESPR documents include a comprehensive analysis of base year noise levels and look
at potential future noise levels assuming a series of future scenarios. These reports are available
for review in the Massport offices and in the libraries of the four contiguous towns.
From 1998 through 2000, Massport staff worked closely with the Noise Working Group, an
outgrowth of the then current GEIR Update. The group, which included aviation and residential
community members, formed two subgroups, one to develop noise abatement/mitigation
recommendations and the other to review and recommend metrics to be used to describe the
Hanscom Field noise environment. The recommendations were submitted to Massport in late
2000.
In 2001, Massport began taking steps to implement most of the recommendations that were
directed to Massport.l Table 6.4 in this report is an example of a metric requested by the Noise
Working Group. Implementation of the upgraded noise monitoring system and the ESPRs
respond to some of the other Noise Working Group requests.
While Massport began actively encouraging quiet flying techniques in the 1980s, the Noise
Working Group's initiatives resulted in a more robust noise abatement awareness program. In
2001, Massport distributed "Fly Friendly" videos to all Hanscom pilots, flight schools, and Fixed
Base Operators (FBOs)2. Massport is now asking all pilots who receive a Hanscom ID badge to
watch a video about quiet flying techniques. The quiet flying techniques are also described on
Massport's website, on posters that are prominently displayed by the flight schools and the
FBOs, and on handouts that are available for pilots to include with their airport flight materials.
Airfield signage also promotes quiet flying.
On another front, Massport was an active participant in Sound Initiative, an organization
spearheaded by general aviation airports that supported federal legislation to phase out Stage 2
aircraft operations in the United States. In 2012, Congress passed the FAA Modernization and
1 Some of the recommendations were directed to Hanscom Air Force Base, the Noise Working Group, or the FAA.
2 A full- service FBO is a company that handles a range of needs for based and transient aircraft, their operators and
their passengers. These include cleaning, maintaining, fueling, and parking/hangaring aircraft, providing flight
planning services for the pilots, and arranging for the specific needs of those flying.
MASSACHUSETTS PORT AUTHORITY
Page 35
Reform Act, which included the phase out of all non -stage 3 aircraft by December 31, 2015.
Section 506 of the Act prohibits the operation, within the 48 contiguous states, of jets weighing
75,000 pounds or less that do not comply with Stage 3 noise levels.
Massport's operation of Hanscom Field assists Massport in meeting its responsibilities to the
regional transportation system, to the business community and to the economic viability of the
region. At the same time, Massport recognizes the issues that are raised by the surrounding
communities and strives to work through HFAC to find mutually acceptable mechanisms to
minimize and /or mitigate those issues.
MASSACHUSETTS PORT AUTHORITY
APPENDIX A (l)
Noise Terminology Used
at Hanscom Field
DNL Noise Contour Maps
Time Above Contour Maps
Excerpts from: 2000 L. G. Hanscom Field Environmental Status and Planning Report and
Draft 2005 L. G. Hanscom Field Environmental Status and Planning Report
Noise Terminology
Noise, often defined as unwanted sound, is one of the most common environmental issues associated with
aircraft operations. Aircraft are not the only sources of noise in an urban or suburban environment where
interstate and local roadway traffic, rail, industrial, and neighborhood sources also intrude on the everyday
quality of life. Nevertheless, aircraft are readily identified by their noise and are typically singled out for —
special attention and criticism. Consequently, aircraft noise problems often dominate analyses of environ-
mental impacts. To help understand and interpret these impacts, it is important to be familiar with the
various metrics that are used to describe the noise from an aircraft and from the collection of noise events
that comprise an airport noise environment. This introductory section describes those commonly used noise
metrics, in increasing complexity. They include the:
• Decibel (dB)
• A- weighted decibel, or sound level (dBA) 7 -3
• Sound Exposure Level (SEL)
• Equivalent Sound Level (Leq)
• Day -Night Sound Level (DNL)
• Time Above (TA)
The Decibel, dB
Sound is a physical phenomenon consisting of minute vibrations that travel through a medium, such as air,
and are sensed by the human ear. Whether that sound is interpreted as pleasant (music, for example) or
unpleasant (aircraft noise, for example) depends largely on the listener's current activity, experience, and
attitude toward the source of that sound. It is often true that one person's music is another person's noise.
The loudest sounds the human ear can comfortably hear have one trillion (1,000,000,000,000) times the
acoustic energy of sounds the ear can barely detect. Because of this vast range, any attempt to represent the
intensity of sound using a linear scale becomes unwieldy. As a result, a logarithmic unit called the decibel
(dB) is used to represent the intensity of sound. This representation is called a sound pressure level.
A sound pressure level of less than 10 dB is approximately the threshold of human hearing and is barely
audible under extremely quiet conditions. Normal conversational speech has a sound pressure level of
approximately 60 to 65 dB. Sound pressure levels above 120 dB begin to be felt inside the human ear as
discomfort and eventually pain at still higher levels.
A- weighted Sound Level, dBA
Additionally, not all sound pressures are heard equally well by the human ear. Some tones are easier to
detect than others and are perceived as being louder or noisier. Thus, in measuring community noise,
frequency dependence is taken into account by adjusting the very high and very low frequencies to approxi-
mate the human ear's reduced sensitivity to those frequencies. This adjustment is called "A- weighting" and
is commonly used in measurements of environmental noise.
Figure 7 -1 shows A- weighted sound levels for some common sounds. In this document, all sound pressure
levels are A- weighted and, as is customary, are referred to simply as "sound levels," where the adjective "A-
Figure 7 -1 Common A- weighted Sound Levels
Common Outdoor Noise Level Common indoor
Sound Leveles dB(A) Sound Levels
it
ylol
Rock Band
Commercial Jet Flyover at 1000 Feet
100
Gas Lawn glover at 3 Feet
-
Inside Subway Train (New York)
..:' Diesel Truck at 50 Feet
90
Food Blender at 3 Feet
7 -4 Concrete Mixer at 50 Feet
80
Garbage Disposal at 3 Feet
Shouting at 3 Feet
Air Compressor at 50. Feet
70
Vacuum cleaner at 10 Feet
Lawn Tiller at 50 Feet
Normal Speech at 3 Feet
sa
Large Business Office
Quiet Urban Daytime
so-
Dishwasher Next Room
Quiet Urban Nighttime an Small Theater, Large Conference Room
(Background)
Quiet Suburban Nighttime Library
30
Quiet Rural Nighttime __ I Bedroom at flight
20 Concert Hall (Background)
Broadcast and Recording Studio
Ya
- Threshold of Hearing
-a-
weighted" has been omitted. Sound levels are designated in terms of A- weighted decibels, abbreviated
dBA. With A- weighting, a noise source having a higher sound level than another is generally perceived as
louder. Also, the minimum change in sound level that people can detect outside of a laboratory environment
is on the order of 3 dB. A change in sound level of 10 dB is usually perceived by the average person as a
doubling (or halving) of the sound's loudness, and this relationship holds true for loud sounds as well as for
quieter sounds.
Sound Exposure Level, SEL
A further complexity in judging the impact of a sound is how long it lasts. Long duration noises are more
annoying than short ones. The period over which a noise is heard is accounted for in noise measurements
and analyses by integrating sound pressures over time. In the case of an individual aircraft flyover, this can
be thought of as accounting for the increasing noise of the airplane as it approaches, reaches a maximum,
and then falls away to blend into the background (see Figure 7 -2). The total noise dose, or exposure, result-
ing from the time- varying sound is normalized to a one - second duration so that exposures of different
durations can be compared on an equal basis. This time - integrated level is known as the Sound Exposure
Level (SEL), measured in A- weighted decibels.
Figure 7 -2 Illustration of Sound Exposure Level
90
80
70
W.
sa
50
40
SEL
Noise Dose
q�
1 Second
1 Minute
i
7 -5
Because aircraft noise events last longer than one second, the tune- integrated SEL always has a value greater
in magnitude than the maximum sound level of the event — usually about 7 to 10 dB higher for most airport
environments. SELs are used in this study as a means of comparing the noise of several significant aircraft
types; they are also highly correlated with sleep disturbance, an impact that is discussed in Appendix G.
The remaining noise metrics discussed in this section refer to the accumulation of exposure caused by
multiple noise events over time. While such metrics are often viewed as downplaying the importance of
individual aircraft operations, they are extremely good indicators of community annoyance with complex
noise environments, and they have become widely accepted as the most appropriate means of evaluating
land use planning decisions.
Equivalent Sound Level, Leq
The most basic measure of cumulative exposure is the Equivalent Sound Level (Leq). It is a measure of
exposure resulting from the accumulation of A- weighted sound levels over a particular period (as opposed
to an event) of interest such as an hour, an eight -hour school day, nighttime, a single 24 -hour period, or an
average 24 -hour period. Because the length of the period can differ, the applicable period should always be
identified or clearly understood when discussing the metric. Such durations are often identified through a
subscript, for example Leq(8) or Leq(24).
Conceptually, the Leq may be thought of as the constant sound level occurring over the designated period of
interest and having as much sound energy as that created by the actual rising and falling sound pressures
from multiple noise sources as they become more or less pronounced. This is illustrated in Figure 7 -3 for the
same representative one - minute of exposure shown earlier in Figure 7 -2. Both the dark and light gray shaded
areas have a one - minute Leq value of 76 dBA. It is important to recognize, however, that the two representa-
tions of exposure (the constant one and the time - varying one) would sound very different from each other
were they to occur in real life.
Figure 7 -3 Illustration of Equivalent Sound Level
i so
7 -6
80
70
m
y
ao
60
50
40
= 76
j Second 1 Minute
Often the Leq is referred to misleadingly as an "average" sound level. This is not true in the traditional sense
of the term average. Because decibels are logarithmic quantities, loud events dominate the calculation of the
Leq. For example, if an aircraft produced a constant sound level of 85 dBA for 30 seconds of a minute then
immediately disappear, leaving only ambient noise sources to produce a level of 45 dBA for the remaining
30 seconds, the Leq for the full minute would be 82 dBA—just 3 dBA below the maximum caused by the
aircraft, not the 65 dBA suggested by normal averaging. More typical timeframes of interest are daytime,
nighttime, and annual average 24 -hour exposure levels, but all of these same principles of combining sound
levels apply to those periods as well. Loud noise events occurring during any timeframe are going to have
the greatest influence on the overall exposure for the period.
The Day -Night Sound Level, DNL
The most widely used cumulative noise metric is a variant of the 24 -hour Leq known as the Day -Night
Sound Level, or DNL, a measure of noise exposure that is highly correlated with community annoyance.
The long -term (yearly) average DNL is also associated with a variety of land use guidelines that suggest
mom
where incompatibilities are expected to exist between the noise environment and various human activities.
Because of these strengths, the metric is required to be used on airport noise studies funded by the Federal
Aviation Administration (FAA).
In simple terms, DNL is the equivalent sound level for a 24 -hour period, modified so that noises occurring at
night (defined specifically as 10:00 p.m. to 7:00 a.m.) are artificially increased by 10 dB. This "penalty"
reflects the added intrusiveness of nighttime noise events as community activity subsides and ambient noise t
levels get quieter. The penalty is mathematically equivalent to multiplying the number of nighttime noise
events by a factor of ten.
�i
The U.S. Environmental Protection Agency (EPA) identified DNL as the most appropriate means of evaluat-
ing airport noise based on the following considerations':
k
• The measure should be applicable to the evaluation of pervasive long -term noise in various defined
areas and under various conditions over long periods of time._ 7 -7
• The measure should correlate well with known effects of the noise environment and on individuals
and the public.
• The measure should be simple, practical and accurate. In principal, it should be useful for planning
as well as for enforcement or monitoring purposes.
• The required measurement equipment, with standard characteristics, should be commercially
available.
• The measure should be closely related to existing methods currently in use.
• The single measure of noise at a given location should be predictable, within an acceptable toler-
ance, from knowledge of the physical events producing the noise.
• The measure should lend itself to small, simple monitors, which can be left unattended in public
areas for long periods of time.
Despite these origins, the lay public often criticizes the use of DNL as not accurately representing communi-
ty annoyance and land use compatibility with aircraft noise. Much of that criticism stems from a lack of
understanding of the measurement or calculation of DNL. One frequent criticism is based on the feeling that
people react more to single noise events than to "meaningless" time - average sound levels. In fact, DNL takes
into account both the noise levels of all individual events occurring during a 24 -hour period and the number
of times those events occur. The logarithmic nature of the decibel causes noise levels of the loudest events to
control the 24 -hour average, just as they were shown to do in the previous discussion of shorter -term Leqs.
Most federal agencies dealing with noise have formally adopted DNL, though they also encourage the use of
supplemental noise metrics to aid the public in understanding the complex noise environment of an airport.
For example, Massport frequently uses the Sound Exposure Level, maximum sound level, or times above
threshold sound levels to help describe the environments around Hanscom Field and Logan International
Airport. Even so, the Federal Interagency Committee on Noise ( FICON), comprised of member agencies
such as the FAA, Department of Defense (DoD), U.S. EPA, Department of Housing and Urban Development
(HUD), National Aeronautics and Space Administration (NASA), Council on Environmental Quality (CEQ),
and the Department of Veterans Affairs, reaffirmed the appropriateness of DNL in 1992. The FICON sum-
mary report stated, "There are no new descriptors or metrics of sufficient scientific standing to substitute for
the present DNL. cumulative noise exposure metric ".' The Federal interagency Committee on Aviation Noise
(FICAN) recently supported the use of supplemental metrics in its statement that "supplemental metrics pro-
vide valuable information that is not easily captured by DNL
DN'L can be measured or estimated. Measurements are practical only for obtainin- DNL values for a rela-
tively limited number of points, and, except in the case of a permanently installed noise monitoring system,
only for relatively short time periods. Most airport noise studies are based on computer - generated Dl\Ti esti-
mates, depicted in terms of equal- exposure noise contours, much as topographic maps have contours of
equal elevation.
L
Time Above a Threshold, TA
Because. analyses of decibels are complex and often unfamiliar to the public, the FAA has developed a sup -
plemental noise metric that is non -logarithmic: the amount of time (in minutes or seconds) that the noise
source of interest exceeds a given A- weighted sound level threshold. Every time a noise event goes above
7 -8 a given. threshold, the number of seconds is accumulated and added to any previous periods that the noise
exceeded the threshold. These time- above - thresholds, or Time Above (TA), are usually reported for a ?4-
hour period_
Note that TA does not tell the loudness of the various noise events. Just as a single value of the A- weighted
sound level ignores the dimension of time; so the TA ignores the dimension of loudness. Nevertheless, TA
call. be helpful in better understanding a noise environment.
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1- :'S. .`� •� 1 �� -� i 14 .�- V i ��. A�♦ S � U � V 1- N N O
APPENDIX B
2011 Average Daily Operations and
Noise Exposure by Aircraft Type
APPENDIX B
2011 Average Daily Operations and Noise Exposure by Aircraft Type
AVERAGE DAILY DEPARTURES, ARRIVALS, AND EXP 6.1 FOR 2011
Reference Dep. SEL:
15,000 R Tram
Aircraft Representative Brake Release
Group Types (in dB)
DEPARTURES
Day Night Total
lopm -7am
Partial
EXP
6.1
Reference Am. SEL:
8,000 R from
Landing Threshold
(in dB)
Day
ARRIVALS
Night Total
10pm -7am
Partial
EXP
- 6.1
1
C500, C501
87.3
1.38
0.03
1.41
89.6
83.0
1.36
0.05
1.41
85.5
2
MU3, C550, C560
91.9
5.37
0.27
5.64
100.9
84.5
5.26
0.37
5.63
94.0
2M
T47 (MILITAR)l
91.9
0.01
0.00
0.01
70.7
84.5
0.01
0.00
0.01
63.3
3
BE40, LR35, LR55, DAIO &200
91.2
8.97
0.47
9.44
102.6
85.6
8.86
0.61
9.47
97.4
H25 -700 & 800, N265 -65
0.00
3M
C -21 (MILITARY)
912
0.10
0.00
0.10
813
85.6
0.10
0.00
0.10
75.7
4
DA02
95.9
0.02
0.00
0.02
82.9
96.1
0.02
0.00
0.02
79.4
4M
HU25
95.9
0.00
0.00
0.00
70.3
96.1
0.00
0.00
0.00
70.5
5
LR23, 24, 25, N26540 & 60, H25 -40C
105.2
0.08
0.01
0.09
97.2
97.5
0.08
0.01
0.09
89.9
5M
T- 37, 38, & 39 (MILITARY)
105.2
0.00
0.00
0.00
79.1
97.5
0.00
0.00
0.00
71A
6
BACA 11
97.3
0.00
0.00
0.00
0.0
97.1
0.00
0.00
0.00
0.0
7
G3
972
0.15
0.00
0.15
90.8
90.6
0:16
0.00
0.16
83.7
7M
C20
97.2
0.02
0.001
0.02
79.1
90.6
0.02
0.00
0.02
72.5
8
G4
82.1
3.28
0.26
3.54
89.8
86.1
3.11
0.43
3.54
94.8
8M
C20B, G4 (MILITARY)
82.1
0.00
0.00
0.00
0.0
86.1
0.00
0.00
0.00
0.0
9
CL60, DA2000, GALX
86.7
4.33
0.29
4.62
95.3
85.0
4.25
0.38
4.63
94.0
10
CL61 & 64, CARJ
84.7
3.49
0.17
3.66
91.8
86.0
3.41
0.25
3.66
93.7
11
UNKNOWN/MISC JETS (G.A.)
96.7
0.11
0.02 r
0.13
92.1
99.1
0.11
0.03
0.14
95.7
1IM UNKNOWN/MISC JETS (MIL)
100.4
0.01
0.00
0.01
77.9
89.0
0.01
0.00 r
0.01
67.4
12
C140 (MILITARY) Obsolete
0.00
0.00
0.00
0.0
0.00
0.00
0.00
0.0
13
C141 (MILITARY)
104.4
0.00
0.00
0.00
0.0
108.2
0.00
0.00
0.00
0.0
14
DC -9
94.4
0.02
0.02
0.04
87.0
91.1
0.02
0.06
0.08
88.8
14M C9, T -43 (MILITARY)
99.5
0.01
0.00
0.01
78.2
92.2
0.01
0.00
0.01
70.9
15
8707 Obsolete
0.0
0.00
0.00
0.00
0.0
0.0
0.00
0.00
0.00
0.0
15M C -5A, KC -135, C137 (ML)
103.6
0.06
0.00
0.06
93.1
99.8
0.06
0.00
0.06
90.3
16
Aaft moved to att. Groups
0.00
0.00
0.00
0.0
0.0
0.00
0.00
0.00
0.0
17
HELICOPTERS (GA.)
83.4
9.52
0.32
9.84
94.5
87.9
9.49
0.42
9.91
99.3
17M HELICOPTERS (MILITARY)
80.8
0.04
0.00
0.04
66.5
89.4
0.04
O.DO
0.04
75.1
18
G159, CV60 - HVYTURBOS
89 -9
0.00
0.00
0.00
0.0
94.6
0.00
0.00
0.00
0.0
IBM C130- HVYTURBOS(MILITARY)
93 -1
0.10
0.00
0.10
83.0
93.5
0.10
0.00
0.10
83.4
19
BE20,30- TURBOS
81.9
5.10
0.06
5.16
89.5
91.1
5.07
0.10
5.17
98.9
19M C12, T44, C26 -TURBOS (MIL)
81.9
0.20
0.00
020
75.4
91.1
0.20
0.00
0.20
84.6
20
TWIN PISTON -BE56, C310 (GA.)
82.6
4.75
0.14
4.89
90.5
83.7
4.81
0.08
4.89
91.2
20M T1MN PISTON - C45,T42 (MIL)
82.6
0.00
0.00
ODD
0.0
83.7
0.00
0.00
0.00
0.0
21
SINGLES -INC. LOCALS (GA.)
78.5
162.19
0.25
162.44
100.7
79.4
162.06
0.39
162.45
101.6
21M SINGLES (MILITARY)
782
0.06
0.00
0.06
66.3
79.4
0.06
0 -00
0.06
67.5
22
WW24,VWV25
90.9
1.62
0.07
1.69
94.7
82.5
1.59
0.10
1.69
86.7
23
FK2B -Moved to Unidentified
0.00
0.00
0.00
0.0
0.00
0.00
0.00
0.0
24
A-4,6, F- 14,15,16,18 (ML)
117.0
0.07
0.00
0.07
105.7
93.2
0.07
0.00
0.07
81.9
25
C650
88.8
0.22
0.00
022
83.1
82.5
0.21
0.00
021
77.4
26
DA50, DA90
93.0
2.28
0.13
2.41
98.5
87.4
2.26
0.15
2.41
93.2
27
CV58- TURBO
81.9.
0.00
0.00
0.00
0.0
91.5
0.00
0.00
0.00
0.0
28
DC3,CV24- HVYTWWPISTONS
94.7
0.00
0.00
0.00
0.0
95.6
0.00
0.00
0.00
0.0
28M DC3- HVY TWIN PISTONS (MIL)
94.7
0.00
0.00
0.00
0.0
95.6
0.00
0.00
0.00
0.0
29
AC6T, BE90, PA31T- TURBOS
75.3
0.49
0.02
0.51
73.7
81.9
0.50
0.01
0.51
79.9
30
SF34 -TURBO
77.4
0.00
0.00
0.00
62.6
84.0
0.00
0.00
0.00
692
31
B727 (STAGE 2) Obsolete
0.00
0.00
0.00
OD
0.00
0.00
0.00
0.0
32
B727 (STAGE 3)
103.8
0.00
0.01
0.01
94.12
94.7
0.01
0.01
0.02
80.84
33
BEST, ND26 - TURBOS
83.0
0.00
0.00
0.00
0.0
85.3
0.00
0.00
0.00
0.0
34
8737
95.6
0.02
0.01
0.03
84.1
91.8
0.02
0.01
0.03
82.7
35
DH8
70.3
0.04
0.00
0.04
60.2
81.1
0.04
0.01
0.05
72.0
36
A320, A319
89.5
0.02
0.00
0.02
75.7
91.1
0.02
0 -00
0.02
77.3
37
GLEX, G5
862
2.26
0.18
2.44
92.3
86.5
2.20
0.24
2.44
932
37M C37, G5
86-2
0.00
0.00
0.00
61.1
86.5
0.00
0.00
0.00
61.4
38
SBR1 -80
95.9
0.00
0.00
0.00
69.8
96.0
0.00
0.00
0.00
69.9
39
G2
99.6
0.19
0.00
0.19
92.9
92.3
0.17
0.01
0.18
87.1
40
C750
82.0
2.03
0.11
2.14
86.8
89.1
1.98
0.15
2.13
94.6
41
8738
91.1
0.18
0.05
023
89.1
92.4
0.17
0.08
0.25
92A
42
8757
87.0
0.03
0.00
0.03
71.4
91.0
0.03
0.00
0.03
78.2,
43
EA50, C510
83.0
1.48
0.07
1.55
86.3
87.4
1.43
0.13
1.56
91.7
TOTALS
CIVILIAN W/O SINGLES
57.44
2.72
60.16
108A
56.67
3.70
60.37
106.9
CIVILIAN W /SINGLES
219.63
2.97
222.60
109.1
218.74
4.09
222.83
1082
MILITARY
0.68
0.00
0.68
106.0
0.68
0.01
0.69
92.7
TOTAL W/O SINGLES
58.05
2.72
60.77
110.4
57.29
3.71
61.00
107.3
TOTAL W /SINGLES
220.31
2.97
22328
110.8
219.42
4.10
223.52
108.3
APPENDIX C
1995, 2000, 2005, 2010 & 2011 Measured DNL (dBA)
at
Hanscom Noise Monitoring Sites
LO N Ihr -7 Lq V' O m 1•hN m m M rr mN M
m N m 1• m m N (O -�t m m m N G m v m o m N
m m m mmm N m m m m m m N 'm m m m m m
Omf N N m m V' T Cl! It m m 1, r m M. N 1-, m N
m N Cl) m a) O - m� V m O N m M N 7 m O m
N .mmmm m m N m m m m m m O 1- m m m m m
� O aoi
cl
O m lh m m m m m m m a) r M •7 m 0 7 N c•)
I- m m r O m m m 'V' m � N 10 m N m N m N
o (D ED m m o m m m m m m o r m m m m m
Z Z >o
Z
I j ti V m O O M a1 O 11 a) r m I r m N m 0
m to •7 m M r N _ r- m v M N �O O V m O M
m m m m m m U m m m m m m O f` m m m m m
U U U
O O
m m M V' O m Ci p m N ti m t` m O d: a) m m m
m
IT m Cl) m N - m M m m O N r- r r O W
m m m m m m m m m m m m m m m m m m
(A (!J (n M
w
amj 1- V N Ih m p a) m O N N aD p N Cl! Cl! M V O
M M M M N m [t to O m r Ih N O N m N -O
m m m m m m 3 m m m m m m m m m m m m m W
Q Q Q U
W
a
m ti r m M n p m m m V m N m0 r a) m M m r 'rC-
m V h m r - mNmmm N - m rmm 1-m -O
m m m m m m 3 m m m m m m 7 m m m m m m 0
7
W
m
M a) m M m r °O m O m M V M p Q) 7 0 m r m
a� m m m m V V m ((i M Ih 0 a) (`7 v m M M M r 'p
r t• m m m m m m m m m m m m m m m m m
C W R 75
n
m N m� m M N p0 m m N m r r N O) aI r m N N W
7 N m m m N U- m m m m O M mqr m N r- N
mmmmmm of ca mmmmmm m m m m m m 0 =
ca
Z 0 O
LO
a
M N (O r is r p O co q. m M ; R v N N O O O T C
t-- N CO m N N «O m M m O O M O m m m O W 4 a7 D O
`d CO m m m m m 'C m o_ m m m m m m CO CO m CO m CO 3
Q o m Q O a m
E Q O C N
A2 0 amj (q a) r O m L t- O M m -: r,-: m m m M T N m m m N Q C
m m m O N ' r m •7 m m O M O R? 7 m m N 0
m m m m m p m R m m m m m m m m m m m m m 0 i
(0 r r O a
V
N U C
L W
m 01 M '7 O R 00 a) a7 d) h M M p N C
ti "r I` m r .L4')
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m m m m m 0 mmmmmm 0 m m m m m m g r.
LL C LL ID
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m ro mMm ; °° mm10wI-m o I�mmmh.l� Wa
m m h m N 3 O rl: N 4 m a) M m M M a) m
c m m m m m a m mmmmmm m mmmmmm y a w
ca O m ° --a -� 00 O 'o
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(/l O C
W - m C ' p
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W W `
a ❑ C J y(c' « J a U �o ' d a 'W d ' d y 3 R U U`° O O C U - a ❑ O � N N 6 ` U a N QOm o i ' m -N O ° Q C O C a m` U c
W -0 0 c (D a 0 c O c
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CO 7O N C - U N Y O N m O
`6 m a m o Q N O Q
O o 0 0 0 W
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J 0 J N J d 6 E o ca o o O c m o
U 0 ° c a) Q N 0-0 5R C: 0 a -0
0 0 c 0 s N C O
0 0 u E 0 0 0 C 0 0 0 0 0 C 0 0 0
U m J m J U n 0` U m J m J U U m J 03 J U __
Q M '� C (p ❑ L O M M M M M M ❑ Lp M N M M M R M m N M m U 0 M M M M M M (
2 m M
+
O
a] m r 1- N m
MP,� N r m O
p
m M m m O r p
m M m O m
N
m m m m m to N
m m mmm m
O
r ti O h
m N lh r--: m N
U
m m m 0 U
M N m m m N
W
mmmm m m
m m m m m m
O
r
aI r• h M m m Y �--
7 O m m m
>
m M m r o o N >
V N m 0 N
Zm
m m m m m Z
m m m m m m
0
O
r
C
M OD h ti M M R r
M 0 m-'r 7 0
j�
V' m o o
m m m m m m o
m m m m m m
O
C
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m m M m M N
m v m m m M
(r0 m m m m m W
W
mmmmm m
O
m (O a1 V L r
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F-
rnl-mmmmm
• N t!1 m 6 « 01
m m m O O N
mmmmmm
w U Q
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a .ca
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r m r
r O) Mr- a W _
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m W Q
n M rm N
7 m? m m M
C
ON C
m m m m m m C N 3
m c'im o m
m m m m m m
p
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r
m N V: W m M O r -`-
O m m CO N m
m (a L C (OO co N L •Q u
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p_mmm
m N m C m (h C C Q
mm
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m
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r
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m m 0) m m 0
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m L m m� C
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°
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a N QQ
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U m J m J U. i U m J m J U
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