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FAA

Airspace Policy, Environmental Team (AJV-114)

Evaluation of Changes to the FAA’s 

Proposed Action regarding the 

Re-designation and Expansion of Restricted 

Area R-4403 

Introduction

The public provided comments in response to both an FAA Notice of Proposed Rulemaking 

(NPRM) published in July 2014 and a Supplemental Notice of Proposed Rulemaking (SNPRM) 

published in August 2014 regarding the re-designation and expansion of Restricted Area R-4403 

at Stennis Space Center (SSC) in Hancock County and Pearl River County, Mississippi and St. 

Tammany Parrish, Louisiana. The proposed rule would remove R-4403 and replace it with an 

expanded restricted airspace consisting of R-4403A, R-4403B, R-4403C, R-4403E, and R-4403F 

(hereinafter “the Proposed Restricted Areas”). Commenters on the NPRM and SNPRM 

expressed concerns about the potential impact of the Proposed Restricted Areas on aircraft 

transiting the area and on published instrument approach procedures serving Picayune Municipal 

Airport (MJD) and Stennis International Airport (HSA). The FAA has developed a number of 

mitigation measures to address these concerns, including: 

- Revisions to instrument approach procedures serving MJD

- Revisions to instrument approach procedures serving HSA

- Addition of two visual flight rules (VFR) waypoints south of Interstate 10 to assist pilots 

navigating along Interstate 10 to avoid inadvertently flying into the Proposed Restricted

Areas.
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These mitigation measures were not evaluated or analyzed in the United States Navy’s and 

National Aeronautics and Space Administration’s (NASA) Final Environmental Assessment for 

the Redesignation and Expansion of Restricted Airspace R-4403 to Support Military 

Air-to-Ground Munitions Training and National Aeronautics and Space Administration Rocket 

Engine Testing at Stennis Space Center, Hancock County and Pearl River County, Mississippi 

and St. Tammany Parrish, Louisiana, dated October 2015 (hereinafter “the FEA”). Due to the 

nature of the mitigation measures and their potential for environmental impact, the FAA has 

determined that they do not require supplementation of the FEA. The discussion below explains 

the basis for this determination. 

 

Revisions to Instrument Approach Procedures

MJD:

The current RNAV (GPS) RWY 18 would be split into two separate approaches, a Y variant and a 

Z variant. The Z variant would be active when the SUA is active. The change that would impact 

the flight path of aircraft is the missed approach course. The missed approach course in the 

existing procedure directs aircraft east of the airfield. The revised missed approach course would 

direct aircraft west of the airfield and away from the Proposed Restricted Airspace.

RNAV (GPS) RWY 36: This procedure would be inactive when the Proposed Restricted Airspace 

is active. Aircraft would not be able to approach the airfield from the south.

VOR A: The major changes are a 3° change in course, from 132° to 129°, to the runway and the 

elimination of circling for Category D aircraft (those with approach speeds between 141-165 

knots) and Category C aircraft (121-140 knots). These changes would direct aircraft further north 

of the airfield during their approach and allow them to avoid the Proposed Restricted Airspace 

during a missed procedure.

HSA:

The current ILS or LOC RWY 18 would be split into two separate approaches, a Y variant and a Z 

variant. The Z variant would be active when the Proposed Restricted Airspace is active. The 

change to the procedure that would impact the flight path of aircraft is moving the start of the 

approach further 8.6 nautical miles further north to avoid the expanded Proposed Restricted 

Airspace and tie in to an existing Visual Flight Rules Airway. In addition, the holding pattern for 

missed approaches would move further north.

RNAV (GPS) RWY 18: The change to the procedure that would impact the flight path of aircraft 

is moving the start of the approach 1.1 nautical miles further north which essentially would lower 

the altitude of the approach by 9.2%. 

Establishment of New VFR Waypoints
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The new VFR waypoints south of I-10 would assist VFR pilot navigation by providing navigational 

reference points, and would not specify a flight path or direct the flow of air traffic. As such they 

are considered advisory actions, which are not subject to the National Environmental Policy Act 

(NEPA). Therefore, no further environmental analysis is required for this action.

Environmental Analysis

The changes to the approach procedures at MJD would alter how aircraft fly to the runway and fly 

missed approaches. They would not change the number, time, or type of aircraft operations, nor 

would they result in any disturbance of the ground or ground based resources. The changes 

would not result in any additional flight miles.

The changes to the approach procedures at HSA would shift the start of southbound approaches 

further north of the airfield resulting in slightly reduced flight altitudes. In addition the holding 

pattern would be shifted further north to the new start of the revised approach as would the point 

to where aircraft will fly after a missed approach. Aircraft that missed an approach would fly 8.9 

nautical miles further north thereby adding roughly 18 nautical miles to each missed approach. 

The changes to these approach procedures would not result in any change in the time, type or 

level of operations at HSA, nor would they result in any disturbance of the ground or ground 

based resources. 

Based on the results of the noise analysis (see below), the changes to the instrument approach 

procedures at MJD and HSA fall within the scope of the categorical exclusion in paragraph 5-6.5.i 

of FAA Order 1050.1F, which includes “modifications to currently approved procedures conducted 

below 3,000 feet [above ground level (AGL)] that do not significantly increase noise over noise 

sensitive areas.” This categorical exclusion reflects the FAA’s determination, approved by the 

Council on Environmental Quality, that such actions normally do not cause significant 

environmental effects, either individually or cumulatively. It would be extraordinary for such an 

action to have the potential to cause significant environmental effects. Paragraph 5-2 of FAA 

Order 1050.1F includes a list of circumstances that could involve a potential for significant 

environmental impact from an otherwise categorically excluded action. These circumstances are 

addressed under “Extraordinary Circumstances” below.

Air Quality and Climate 

The FAA reviewed 30 random days of radar and operations data for MJD and determined that the 

number of operations and miles flown (and resultant fuel burn) would not change, and as such 

the changes to the approach procedures at Picayune Municipal would result in no additional fuel 

burn that in turn would result in an increase in air emissions. As such the changes to the

approach procedures at MJD would have no impact on air quality.

The FAA reviewed 28 random days of radar and operations data for HSA and determined that 

there would be a potential increase in miles flown for aircraft approaching from the north that 

conduct missed approaches. Each missed approach event would add roughly 18 nautical miles 
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at an altitude of approximately 2,000 feet AGL that would otherwise not be flown. The review of 

the data indicates that a missed approach (including training) is flown on average once a day. 

The FAA conducted an analysis to estimate changes in emissions from the modified missed 

approach procedures. Only the tracks captured within the 28 days of radar data identified as

causing an increase in miles flown and thus causing the change to the air quality emissions were 

analyzed. The emissions from these tracks were calculated on an annualized basis within the 

Aviation Environmental Design Tool (AEDT) flying without the modified missed approach 

(Baseline) and then flying with the modified missed approach (Alternative). In order to model the 

missed approaches each missed approach was modelled as three separate flights, an arrival, a 

departure back to the holding point, and a then as a new arrival. This resulted in an extremely 

conservative approach as the model assumes that a departing aircraft is emitting more VOCs 

than a cruising aircraft.1Table 1 below shows the change in emissions (Alternative minus 

Baseline), compared to the highest de minimis level for each pollutant under the U.S. 

Environmental Protection Agency’s general conformity rule (40 C.F.R. § 93.153(b)).

2

 

CO 

(tons)

VOC 

(tons)

NOx 

(tons)

SOx 

(tons)

PM 2·5 

(tons)

PM 10 

(tons)

Impact of Procedure 

(Alternative-Baseline) -237.03 13.67 5.17 0.001 -0.116 -0.116

Highest EPA De 

Minimis Level

100 100 100 100 100 100

Exceedance of 

De Minimis Level? No No No No No No

Table 1: Air Quality Analysis Results for Approach Procedure Changes at HSA.

Table 1 does not include the de minimis level for lead because AEDT does not model lead 

emissions, but the EPA has released guidance on how to calculate these emissions. Using the 

document Lead Emissions from the Use of Leaded Aviation Gasoline in the United States

 

1

Individual pollutant results vary within the AEDT model depending on engine type and 

activity. The type of engine (jet/piston/turboprop), the fuel flow into the engine, the engine mode, 

the time in each engine mode, the temperature of the engine, and the atmospheric pressure at 

that particular place all impact how much of each sort of combustion is occurring and thus impact 

the differences in emissions. See AEDT 2a Technical Manual (available at 

https://www.faa.gov/about/office_org/headquarters_offices/apl/research/models/aedt/media/AED

T2a_TechManual_2012August31b.pdf), pages 149-159 for more detail.

2

The highest de minimis levels are used because the relevant Air Quality Control Region is 

classified as attainment/unclassifiable for all criteria pollutants. 
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(EPA420-R-08-020, October, 2008), the following formula is given for the calculation where the 

LTO operations of piston aircraft are known:

Pb (kg) = (piston-engine LTO)*(7.0*10-3)

From the aircraft above, two out of the 22 total aircraft in these track sets modeled were piston 

aircraft, which corresponds to 26 annual piston aircraft operations. Since we’re looking at missed 

approaches which contains actions that simulate parts of an arrival procedure and part of a 

departure procedure, we’ll conservatively assume that 1 operations = 1 LTO cycle in this case. 

Given this assumption, the annual Pb emissions are 0.182 kilograms or 0.0002 tons, which is well 

under the EPA’s de minimis level of 25 tons. 

Based on these results, the changes in the approach procedures would not have the potential to 

cause a significant effect on air quality, as defined in FAA Order 1050.1F.

The same AEDT analysis reported an annual increase in CO2 emissions of 3.5 metric tons per 

year, which constitutes an insignificant increase in terms of climate when compared to the 

6,708.3 x 106 metric tons of CO2 released in the U.S. in 2011.

Noise Analysis

The FAA conducted a noise screening analysis for the proposed procedure changes at MJD and 

HSA to determine if there would be any “reportable” or “significant” increase in noise over noise 

sensitive areas as defined in FAA Order 1050.1F. The analysis for MJD was conducted using the 

Aviation Environmental Screening Tool. The results of the analysis showed no noise increase at 

or above DNL 45 dB, and thus no reportable or significant noise increase.

The analysis for HSA was conducted using the Terminal Area Route Generation, Evaluation, and 

Traffic Simulation (TARGETS) Aviation Environmental Design Tool (AEDT) Environmental PlugIn tool. The results of this analysis also showed no reportable or significant increase in noise.

Extraordinary Circumstances

Based on the above analysis, and consistent with paragraph 5-2.b of FAA Order 1050.1F, the 

FAA has determined the above-described procedure changes at MJD and HSA would not involve 

any extraordinary circumstances because they would not:

1) cause an adverse effect on cultural resources protected under the National Historic 

Preservation Act of 1966, as amended, 54 U.S.C. §300101 et seq.;3

 

3

Based on the nature of the procedure changes and their potential for environmental impact, the 

FAA has determined that they are not a type of activity that has the potential to cause effects on 

historic properties under 36 C.F.R. § 800.3(a).
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2) have the potential to cause a significant impact on properties protected under Section 4(f);

3) have the potential to cause a significant impact, ecological, or scenic resources of Federal, 

state, tribal, or local significance (e.g., federally listed or proposed endangered, threatened, or 

candidate species, or designated or proposed critical habitat under the Endangered Species Act, 

16 U.S.C. §§ 1531-1544);

4) have the potential to cause a significant impact on the following resources: resources protected 

by the Fish and Wildlife Coordination Act, 16 U.S.C. §§ 661-667d; wetlands; floodplains; coastal 

zones; national marine sanctuaries; wilderness areas; National Resource Conservation Servicedesignated prime and unique farmlands; energy supply and natural resources; resources 

protected under the Wild and Scenic Rivers Act, 16 U.S.C. §§ 1271-1287, and rivers or river 

segments listed on the Nationwide Rivers Inventory (NRI); and solid waste management;

5) cause a division or disruption of an established community, or a disruption of orderly, planned 

development, or an inconsistency with plans or goals that have been adopted by the community 

in which the project is located;

6) cause an increase in congestion from surface transportation (by causing decrease in level of 

service below acceptable levels determined by appropriate transportation agency, such as a 

highway agency);

7) have the potential to cause a significant impact on noise levels of noise sensitive areas;

8) have the potential to cause a significant impact on air quality or a violation of Federal, state, 

tribal, or local air quality standards under the Clean Air Act, 42 U.S.C. §§ 7401-7671q;

9) have the potential to cause a significant impact on water quality, sole source aquifers, a public 

water supply system, or state or tribal water quality standards established under the Clean Water 

Act, 33 U.S.C. §§ 1251-1387, and the Safe Drinking Water Act, 42 U.S.C. §§ 300f-300j-26;

10) cause impacts on the quality of the human environment that are likely to be highly 

controversial on environmental grounds, as defined in paragraph 5 2.b of FAA Order 1050.1F; 

11) be likely to be inconsistent with any Federal, state, tribal, or local law relating to the 

environmental aspects of the proposed action; or

12) otherwise have the potential to directly, indirectly, or cumulatively create a significant impact 

on the human environment.

Conclusion

Based on the foregoing analysis, and consistent with Paragraph 9-3 of FAA Order 1050.1F and 

40 C.F.R. § 1502.9(c)(1), the FAA has determined that the above-described procedure changes 
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at MJD and HSA are not “substantial changes” to the FAA’s proposed action that are “relevant to 

environmental concerns,” and therefore do not require supplementation of the FEA. 
HSA TARGETS Environmental Plug-in Report Page 1 of 19

TARGETS

AEDT Environmental Plug-in Report

For

Stennis International Airport

KHSA

Bay St Louis, Mississippi

Prepared by:

Justin Hodgins

ATO, AJV-114, Environmental Policy Team Office

202-267-6619

justin.ctr.hodgins@faa.gov

March 21, 2016
HSA TARGETS Environmental Plug-in Report Page 2 of 19

Stennis International Airport (HSA)

TARGETS Environmental Analysis Process

1. Purpose

The purpose of this report is to document the process used to analyze the noise impact of a proposed 

changes to instrument flight procedures at Stennis International Airport (HSA). Figure 1-1 shows the 

airport diagram for HSA. This report shows the analysis of instrument flight procedures at HSA using the 

Terminal Area Route Generation, Evaluation, and Traffic Simulation (TARGETS) Aviation 

Environmental Design Tool (AEDT) Environmental Plug-In tool. Table 1-1 shows the procedure names

and types to be modeled.

Figure 1-2 shows the existing ILS or LOC procedure to be replaced by two of the proposed procedures. 

The proposed ILS or LOC procedures will establish a “Y” variant and a “Z” variant. The proposed ILS or 

LOC procedures are shown in Figures 1-3 and 1-4. Figure 1-5 shows the existing RNAV procedure to be 

replaced by a new RNAV procedure, which is shown in Figure 1-6.
HSA TARGETS Environmental Plug-in Report Page 3 of 19

Figure 1-1: Airport Diagram of HSA

Procedure Name Procedure Type

ILS or LOC Y RWY 18 ILS or LOC

ILS or LOC Z RWY 18 ILS or LOC

RNAV (GPS) RWY 18 RNAV

Table 1: HSA Procedures to Be Modeled
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Figure 2-2: Current Published ILS or LOC Approach Procedure
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Figure 3-3: Proposed Procedure ILSY or LOCY RWY 18
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Figure 4-4: Proposed Procedure ILSZ or LOCZ RWY 18
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Figure 5-5: Current Published RNAV Approach Procedure
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Figure 6-6: Proposed Procedure RNAV (GPS) RWY 18
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2. Methodology

Historic radar track data for HSA was obtained from the FAA’s National Offload Program (NOP).

Twenty Eight days of radar track data totaling 347 tracks were selected for the HSA analysis representing 

a range of temperature and wind conditions as well as being representative of the average runway usage.

The dates selected for this project were the following:

01/01/2015

01/12/2015

01/25/2015

02/18/2015

03/15/2015

03/28/2015

04/11/2015

04/28/2015

05/05/2015

05/29/2015

06/06/2015

06/18/2015

06/25/2015

07/10/2015

07/24/2015

08/15/2015

08/23/2015

09/19/2015

09/26/2015

09/28/2015

10/05/2015

10/19/2015

11/10/2015

11/16/2015

11/28/2015

11/30/2015

12/17/2015

12/20/2015

These dates represent average traffic counts and traffic flows through various seasons and peak travel 

times for HSA. Historical radar track data (Figures 2-1 and 2-2) was used to create a baseline noise 

exposure, which provides lateral path definition, aircraft fleet mix, departure/arrival stream proportions 

for each runway, and day/night traffic ratios. A legend (table 2-1) shows, by color, the altitudes of the 

track data. 

After the baseline scenario was built, those aircraft operations which were assigned to the proposed 

procedures were modeled as flying the proposed procedure instead of their historical tracks, which 

creates the alternative scenario. Changes to the procedures involved moving waypoint STENN 1.1 

nautical mile north to tie into a victor airway V-552. For the purpose of this report, historical track data 

referenced in relation to STENN refer to the ‘old’ STENN. New procedures being modeled referenced in 

relation to STENN refer to the ‘new’ STENN.

For the procedures modeled for HSA, part of the proposed ILS or LOC procedure involved a change to 

the missed approach. All tracks that had missed their approach in the historic data gathered from NOP 

were modeled on the missed approach course in TARGETS. Missed approaches are difficult to model 

because of the tool’s difficulty in analyzing the altitude profiles of an aircraft that descends and ascends 

on one path within the study boundary, therefore the route for the missed approach course was created as 

a departure. This was done by assigning a copy of all arrivals to a departure route following the missed 

approach course, then doubling the number of arrivals in the alternative scenario compared to the 

baseline scenario. This created the effect of landing using the proposed arrival procedure, departing using 

the proposed missed approach course, and landing again using the proposed arrival procedure. 

The changes in the proposed RNAV procedure consist of moving the holding pattern from the east side 

of STENN to the west side and lowering the altitude of the approaching aircraft. These changes to the 

RNAV procedure created a holding pattern and approach that is identical to that of the proposed ILS or 

LOC Z RWY 18 procedure. In order to model this procedure, one route was created to model both 

procedures together, and all approaching aircraft were assigned to this single route.
HSA TARGETS Environmental Plug-in Report Page 10 of 19

The analysis does not take into account terrain. The altitude controls of the RNAV procedures were used 

to adjust the vertical profile for each modeled aircraft flying the proposed procedure. When a range of 

altitudes was given for a particular waypoint, the lowest point of the range was used in order to model the 

most conservative environmental case. 

The TARGETS Environmental Plug-in uses 0.3 nautical mile dispersion on either side of the centerline 

of a procedure as its default dispersion value. In cases where the model generated by the TARGETS 

Flyability function tracks do not line up on the centerline of a procedure, the dispersion value is assigned 

using 0.3 nautical miles on either side of the outside flyability tracks as the guideline. For the missed 

approach, the dispersion was set to emulate historic flight tracks of aircraft that followed the same course 

described in the proposed missed approach instructions.

For this analysis no procedures were modelled for the baseline scenario. The 28 days of flight track data 

were used as is to generate the baseline noise. The assumptions listed in Appendix A were used to 

construct the alternative scenario.

Once the baseline and alternative scenarios were built, the TARGETS Environmental Plug-in Tool was 

used to generate noise outputs for both scenarios. The Environmental Plug-in Tool uses the Aviation 

Environmental Design Tool version 2b (AEDT 2b) to calculate noise. The noise output files from AEDT 

2b for both the baseline and alternative noise exposures consist of a series of equally spaced grid points,

each assigned a yearly day-night average noise level (DNL) value. This data is then loaded back into 

TARGETS by the Environmental Plug-in Tool, which generates three outputs: baseline noise exposure,

alternative noise exposure, and noise impact.

The noise impact is a comparison between the baseline and the alternative noise exposure that depicts

reportable and significant noise changes at all affected locations per the criteria indicated in FAA Order 

1050.1F (“Environmental Impacts: Policies and Procedures”) and Chapter 32 of FAA Order 7400.2K 

(“Procedures for Handling Airspace Matters”). The reportable and significant noise increases and 

decreases (if any) are then depicted on an aerial photograph using Google Earth.
HSA TARGETS Environmental Plug-in Report Page 11 of 19

Figure 2-1, HSA Arrival Traffic Used in Analysis

Figure 2-2, HSA Departure Traffic Used in Analysis
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Track Data Legend with Above Ground Level (AGL) and Mean Sea Level (MSL) 

Altitudes

Airport: XXX Field Elevation 13

AGL Altitudes MSL Altitudes Legend Colors

1000 1013

2000 2013

3000 3013

4000 4013

5000 5013

6000 6013

7000 7013

8000 8013

9000 9013

10000 10013

11000 11013

12000 12013

13000 13013

14000 14013

15000 15013

16000 16013

17000 17013

18000 18013

Above Above

Table 2-1: Legend for Baseline Arrival and Departure Traffic
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3. Baseline Noise Exposure

TARGEST AEDT Environmental Plug-in generates a noise exposure map using track data that graphically 

illustrates noise exposure around the airport using various colors to represent different DNL levels. The baseline 

noise exposure is shown in Figure 3-1, which depicts the levels and locations of noise exposure above DNL 45 dB 

produced by the historical radar track data for arrivals and departures. Table 3-1 is the legend for the baseline noise 

exposure Figures. The results indicate exposure levels of DNL 45-50 dB at the outer edge of the affected area, 

increasing gradually toward the runway. Noise exposures above DNL 65 dB occur only at the runway.

Figure 3-1, Baseline Noise Exposure in TARGETS

GEOMETRIC SHAPE COLOR DNL VALUE

No Shape None Less 

SQUARE BLUE 45–50 dB

SQUARE LIGHT BLUE 50–55 dB

SQUARE GREEN 55–60 dB

SQUARE YELLOW 60–65 dB

SQUARE ORANGE 65–70 dB

SQUARE PINK 70–75 dB

SQUARE RED 75 dB OR MORE

Table 2-1: Legend for Noise Exposure
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4. Alternative Noise Exposure

TARGEST AEDT Environmental Plug-in generates an alternative noise exposure map by reassigning tracks in the 

baseline to fit the procedures in the alternative scenario. The alternative noise exposure is shown in Figure 4-1,

which depicts the levels and locations of the noise exposure above DNL 45 dB using the proposed procedures. 

Table 4-1 is the legend for the alternative noise exposure Figures. The results indicate exposure levels of DNL 45-

50 dB at the outer edge of the affected area, increasing gradually toward the runway. Noise exposures above DNL 

65 dB occur only at the runway.

Figure 4-1, Alternative Noise Exposure for the Proposed Procedures in TARGETS

GEOMETRIC SHAPE COLOR DNL VALUE

No Shape None Less than 45dB

SQUARE BLUE 45–50 dB

SQUARE LIGHT BLUE 50–55 dB

SQUARE GREEN 55–60 dB

SQUARE YELLOW 60–65 dB

SQUARE ORANGE 65–70 dB

SQUARE PINK 70–75 dB

SQUARE RED 75 dB OR MORE

Table 3-1: Legend for Noise Exposure
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5. Comparison of Baseline and Alternative Noise Exposure

Figure 5-1 shows a side-by-side view of the baseline and alternative scenarios.

Figure 5-1, Noise Exposure changes by comparison of scenarios for the Proposed Procedures in TARGETS
HSA TARGETS Environmental Plug-in Report Page 16 of 19

The following tables show the results of the TARGETS AEDT Environmental Plug-in analysis of the noise grid 

created to analyze noise exposure and impacts. The grid used for the study consists of an area extending 30 

nautical miles (nm) in each direction of the airport. The grid is divided into points measuring .25nm. 

Baseline Exposure:

%65+dB

%65-

60dB

%60-

55dB %55-50db

%50-

45dB %<45dB

0 0 0 0.1 0.2 99.7

The report indicates that 99.7% of the study area is exposed to less than 45dB DNL. Of the remaining study area, 

0.2% is exposed to between 54-50dB DNL, and 0.1% is exposed to 50-55dB DNL.

Alternative Exposure:

% 65+dB

% 65-

60dB

% 60-

55dB % 55-50db

% 50-

45dB

% 

<45dB

0 0 0 0.1 0.2 99.7

The report indicates results identical to the baseline. 99.7% of the study area is exposed to less than 45dB DNL. Of 

the remaining study area, 0.2% is exposed to between 54-50dB DNL, and 0.1% is exposed to 50-55dB DNL.

IMPACT

% Red % Orange % Yellow % No Change % Green % Blue % Purple

0 0 0 100 0 0 0

The impacts measure differences between the baseline and alternative scenarios. In this case, 100% of the study 

area depicted no change in noise exposure. If changes had occurred, the results would be indicated graphically in 

the noise results. The colors listed in the above table reference the following legend for noise impacts.
HSA TARGETS Environmental Plug-in Report Page 17 of 19

Appendix A

This document provides reference for the methodology and reasoning for track assignments used in the 

noise model. It lists the track data as categorized in the project, a description of each track set, and the 

backbone they were assigned to. 

 Three procedures were modeled: 

o ILS or LOC Y RWY18 

o ILS or LOC Z RWY18

o RNAV RWY 18: Proposed Revisions to RNAV RWY 18 procedure, when modelled, is 

essentially identical to ILS or LOC Y RWY18 in flight profile, missed approach, and 

holding pattern. So the modelled revision of ILS or LOC RWY18 was used for both itself 

and RNAV RWY 18.

 Tracks were separated by runway (18 and 36) and by operation (Arrival or Departure)

GEOMETRIC 

SHAPE

COLOR DNL DIFFERENCE

SQUARE PURPLE 45-60 DB WITH A DECREASE OF 5.0 DB OR GREATER

SQUARE BLUE 60-65 DB WITH A DECREASE OF 3.0 DB OR GREATER

SQUARE GREEN 65 DB OR GREATER WITH A DECREASE OF 1.5 DB OR 

GREATER

OVAL RED 65 DB OR GREATER WITH AN INCREASE OF 1.5 DB OR 

GREATER

OVAL ORANGE 60-65 DB WITH AN INCREASE OF 3.0 DB OR GRTEATER

OVAL YELLOW 45-60 DB WITH AN INCREASE OF 5.0 DB OR GREATER
HSA TARGETS Environmental Plug-in Report Page 18 of 19

 Because there were no proposed changes to existing departure procedures, there were no changes 

from the baseline to the alternative scenarios for departures from RWY 18 and departures or 

arrivals to RWY 36

 All the remaining tracks (i.e. RWY 18 Arrivals) were split into three categories. The ILS or LOC 

Y and Z assigned tracks were then copied and/or split into subcategories according to the 

following criteria: 

o Runway 18 arrivals: ILS or LOC Y: These tracks represent the “Y” variant, which 

approaches STENN at 1500. This group contains tracks that were at the lowest altitudes as 

they reached STENN, very close to or below 2000ft.

 ARR:KHSA:ILSY:RW18: tracks that did not use a holding pattern and did not 

miss approach. These tracks were assigned to a backbone that crossed over 

STENN and proceeded straight to the runway.

 ARR:KHSA:ILSY:HLD:RW18: tracks that entered a holding pattern before their 

approach. These tracks were assigned to a backbone that crossed STENN, circled 

twice in a holding pattern, and then proceeded to the runway.

 ARR:KHSA:ILSY:MA01arr:RW18: tracks that missed their approach. These 

tracks were assigned to a backbone that crossed over STENN and proceeded 

straight to the runway. They were then copied and assigned to additional 

backbones to replicate a missed approach 

 DEP:KHSA:ILSY:MAdeparture:RW18: the first copy of the tracks that had 

missed their approach. This track set is identical to the track set above 

(DEP:KHSA:ILSY:MAdeparture:RW18) except that it is modeled as a departure 

that follows the course described in the proposed procedure for missed approaches. 

The backbone connects to the third copy of the track set, modeled as a second 

arrival.

 ARR:KHSA:ILSY:MA02arr:RW18: the third copy of the missed approach track 

set. These tracks are assigned to a backbone that connects to the tracks modeled as 

a departure, continuing to STENN and then entering a holding pattern that circles 

three times and then proceeds to land.

o Runway 18 arrivals: ILS or LOC Z: These tracks represent the “Z” variant, which 

approaches STENN at 2000. This group contains tracks that were at the highest altitudes 

as they reached STENN, above 2000.

 ARR:KHSA:ILSZ:RW18: tracks that did not use a holding pattern and did not 

miss approach. These tracks were assigned to a backbone that crossed over 

STENN and proceeded straight to the runway.

 ARR:KHSA:ILSZ:HLD:RW18: tracks that entered a holding pattern before their 

approach. These tracks were assigned to a backbone that crossed STENN, circled 

twice in a holding pattern, and then proceeded to the runway.
HSA TARGETS Environmental Plug-in Report Page 19 of 19

 ARR:KHSA:ILSZ:MA01arr:RW18: tracks that missed their approach. These 

tracks were assigned to a backbone that crossed over STENN and proceeded 

straight to the runway. They were then copied and assigned to additional 

backbones to replicate a missed approach 

 DEP:KHSA:ILSZ:MAdeparture:RW18: the first copy of the tracks that had missed 

their approach. This track set is identical to the track set above 

 (DEP:KHSA:ILSZ:MAdeparture:RW18) except that it is modeled as a departure 

that follows the course described in the proposed procedure for missed approaches. 

The backbone connects to the third copy of the track set, modeled as a second 

arrival

 ARR:KHSA:ILSZ:MA02arr:RW18: the third copy of the missed approach track 

set. These tracks are assigned to a backbone that connects to the tracks modeled as 

a departure, continuing to STENN and then entering a holding pattern that circles 

three times and then proceeds to land.

o ARR:KHSA:OTHER:RW18: tracks that appeared to follow no procedure and were 

therefore assumed to be VFR flights. These tracks were not assigned to a backbone and 

are the same in the baseline and alternative models. 
MJD AEST Noise Screening Report Page 1 of 10

Aviation Environmental Screening Tool

Report For

Picayune Municipal Airport

MJD

Picayune, MS

Prepared by:

Name: Justin Hodgins

FAA Office: ATO, AJV-114, Environmental Policy Team Office

Phone Number: 202-267-6619

Email Address: Justin.ctr.Hodgins@faa.gov

Date: March 10, 2016
MJD AEST Noise Screening Report Page 2 of 10

Picayune Municipal Airport (MJD)

AEST Environmental Analysis Process

1. Purpose

The purpose of this report is to document the process used to identify and quantify the noise impact of 

the proposed changes to three instrument approach procedures at Picayune Municipal Airport (MJD).

The following study was designed to test for a change in noise over noise sensitive areas as a result in 

adjustments to airport procedures. This report shows the analysis at MJD using the Aviation 

Environmental Screening Tool (AEST). This report refers to the existing historic flight paths as the 

“baseline scenario.” and the proposed changes to the procedure are referred to as the “alternative 

scenario.” Figure 1-1 shows an aerial view of the airport and runway at MJD. Table 1-1 shows the 

procedure names a brief summary of the major changes. Figure 1-2 shows the existing procedures at

MJD. 

The proposed changes to existing Area Navigation (RNAV) approach procedures “RNAV (GPS) RWY 

18” primarily consists of inflight altitude changes, but for this procedure the required altitudes in flight 

will not actually be modified causing no change in the procedure from a noise modeling perspective. For 

the “RNAV (GPS) RWY 36” procedure, the changes to inflight altitudes deal with decision altitudes, 

minimum approach altitudes, and weather minimums. The altitude at the IAF (WISCO) will increase

from at or above 1,800ft to 2,000ft. The changes to the procedure that could affect the noise impact are 

the changes to the missed approach course for each procedure. The changes will result in aircraft no 

longer being directed to the East, but instead being directed North from RWY36 or North via the West 

side of the airport from RWY18 to fix CIQYI (see figures 2-3 and 2-4 in the next section), depending on 

the runway used.

The relevant proposed change to VOR-A is a 3° change in course from 132° to 129° related to a 

MAGVAR change at the airport and the elimination of circling for Category D aircraft (aircraft with 

approach speeds between 141-165 knots) 
MJD AEST Noise Screening Report Page 3 of 10

Figure 1-1: View of Picayune Municipal Airport (MJD)

Name of Procedure Major Change 

Modeled

RNAV (GPS) RWY 18 Change to missed 

approach course

RNAV (GPS) RWY 36 Change to missed 

approach course 

VOR A 3° change in course 

from 132° to 129°

Table 1: MJD Arrival Approaches to Be Modeled

RWY 18

RWY 36
MJD AEST Noise Screening Report Page 4 of 10

Figure 1-2: MJD Existing Procedures RNAV (GPS) RW18, RNAV (GPS) RWY36, and VOR-A
MJD AEST Noise Screening Report Page 5 of 10

2. Methodology

Historic Radar Track Data for MJD was obtained from the FAA’s National Offload Program (NOP). 

Thirty days of radar track data totaling 24 tracks (after removing obvious overflights from the track set) 

were used in the analysis. Days were chosen to capture seasonal weather variation and avoid days where 

significant thunderstorms or high winds may have affected normal operations.

The following dates were used for this analysis:

01/01/2015

01/12/2015

01/25/2015

02/18/2015

03/15/2015

03/28/2015

04/11/2015

04/18/2015

04/28/2015

05/05/2015

05/29/2015

05/30/2015

06/07/2015

06/18/2015

06/25/2015

07/12/2015

08/15/2015

08/23/2015

09/19/2015

09/26/2015

09/28/2015

10/05/2015

10/16/2015

10/19/2015

10/28/2015

11/10/2015

11/16/2015

11/30/2015

12/17/2015

12/20/2015

The arrival procedures in the alternative scenario were created to replicate the proposed procedures. No 

flights in the sampled track data missed their approach, as the missed approach is rarely used. However, 

in order to ensure that even a very rarely used missed approach does not have a noise impact, the 

alternative scenario was built to replicate all flights following the new missed approach procedure. The 

arrival procedures in the baseline scenario were generated in AEST automatically according to the 

sampled track data based on the following ‘bundles’:

Runway 18 Arrivals

Runway 18 VOR Arrivals

Runway 18 Departures

Runway 36 Departures

Runway 36 RNAV East Arrivals

Runway 36 West Arrivals

Missed approaches are difficult to model because of the tool’s difficulty in analyzing the altitude profiles

of an aircraft that descends and ascends on one path within the study border, therefore the route for the 

missed approach course was created as a departure. This was done by assigning a copy of all arrivals to a 

departure route following the missed approach course, and doubling the number of arrivals in the 

alternative scenario compared to the baseline scenario. This created the effect of landing using the 

standard arrival procedure, departing using the missed approach course, and landing again using the 

standard arrival procedure. 

This method is considered valid for the purpose of this project because the noise created in the model 

would greatly exceed the noise created by aircraft following the normal missed approach course. This is 

because the altitude is lower in an arrival/departure that connects to the runway (ending/starting at 0ft 

above ground level, respectively) as it would be in a missed approach. Additionally, the number of flights 

following the course is a conservative estimate when compared to the historical data.
MJD AEST Noise Screening Report Page 6 of 10

The baseline arrival routes were generated by AEST using historical track data (Figure 2-1). Arrivals to 

RWY 36 were split into two bundles: East arrivals and West arrivals. This was done in order to allow 

backbones to more accurately represent the historic flight track data. Normal departures in the alternative 

scenario followed the same routes as in the baseline scenario. As with the arrivals in the baseline 

scenario, these routes were generated automatically in AEST based on the historical track data. For 

simplicity and clarity, these routes are omitted from the images below.

The approach routes used in the alternative scenario were based on the official procedures. RNAV (GPS) 

RWY18 and RNAV (GPS) RWY36 procedures are shown together in Figure 2-2. The alternative missed 

approach course for RNAV (GPS) RWY18 directs aircraft to turn right and proceed directly to fix CIQYI 

(Figure 2-3). The alternative missed approach for (GPS) RWY36 directs aircraft to proceed directly north 

to fix CIQYI and hold to the east (Figure 2-4).

The baseline and alternative VOR-A approaches to RWY 18 reflect a 3° change in course from 132° in 

the baseline scenario to 129° in the alternative scenario. These courses are shown together in Figure 2-5. 

The baseline is shown in red and the alternative is shown in blue. 

AEST assumes that track data is representative of a single day. However, for this study, Thirty days of 

track data were used. AEST allows for adjusting the model to account for more than one day of data. In 

this case, annualization should be set to 3.33%. in order to properly represent an average annual day. For 

this study, annualization was rounded up to 4%. baseline scenarios were run using only historical 

operations, while the alternative scenario was run using double the number of operations to replicate 

missed approaches using the method described above.

Figure 2-1: Baseline scenario arrival routes generated by AEST using historic track data 
MJD AEST Noise Screening Report Page 7 of 10

Figure 2-2: RNAV (GPS) RW18 and RNAV (GPS) RWY36 arrival procedures used in the alternative scenario
MJD AEST Noise Screening Report Page 8 of 10

 

Figure 2-3: Proposed RNAV (GPS) RW18 Missed Approach Course. 

Figure 2-4: Proposed RNAV (GPS) RW36 Missed Approach Course. 
MJD AEST Noise Screening Report Page 9 of 10

Figure 2-4: The Baseline VOR-A Procedure (red) will shift 3°, from 132° to 129°
MJD AEST Noise Screening Report Page 10 of 10

3. Results: Comparison of Noise Exposure in Baseline and Alternative Scenarios

Analysis of noise exposure in the baseline scenario shows that 100% of the study area is exposed to noise

below Yearly Day Night Average Sound Level (DNL) 45 dB. These results are shown in Table 3-1 

below. By comparison, analysis of noise exposure in the alternative scenario shows that 100% of the 

study area is still only exposed to noise below DNL 45 dB. These results are shown in Table 3-2 below. 

Figure 3-1 shows the grid used in the study, and graphically illustrates the results of 100% of the study 

area being exposed to noise below DNL 45 dB. The grid compares the baseline and alternative scenarios 

and indicates the location of increases in noise, if any. 

Based on this analysis using a highly conservative model, the proposed procedure changes will not result 

in any noise increase at or above DNL 45 dB.

#Name Type

DNL 

65+ dB

DNL 65-

60 dB

DNL 60-

55 dB

DNL 55-

50 dB

DNL 50-

45 dB

DNL 

<45 dB

Grid 1

Quiet 

Suburb 0 0 0 0 0 100

Overall 0 0 0 0 0 100

Table 3-1: Count of Points in Baseline Exposure Map. 100% of the study area is below DNL 45 dB noise exposure.

#Name Type

DNL 

65+ dB

DNL 65-

60 dB

DNL 60-

55 dB

DNL 55-

50 dB

DNL 50-

45 dB

DNL 

<45 dB

Grid 1

Quiet 

Suburb 0 0 0 0 0 100

Overall 0 0 0 0 0 100

Table 3-2: Count of Points in Alternative Exposure Map. 100% of the study area is below DNL 45 dB noise exposure.