Community Noise Monitoring Saffron Walden · Saffron Walden Community Noise Monitoring 9 4.2...

Community Noise Monitoring Saffron

Walden John Campbell – Campbell Associates Ltd

Saffron Walden Community Noise Monitoring

1

Page Number

1.0 Overview 2

2.0 Defining Aircraft Noise 4

3.0 Flights Arrivals and Departures 6

4.0 Number of Noise Events 7

4.1 Number of aircraft events per hour 8

4.2 Aircraft Noise Events by Aircraft Type 9

5.0 Maximum noise levels 10

5.1 Maximum levels by aircraft type 10

5.2 Maximum levels by day 11

5.3 Maximum levels by hour of the day 12

6.0 Noise Climate 14

6.1 LAeq average and L90 background noise 14

6.2 Average noise, Aircraft Noise and Residual noise 15

6.3 Lden values 16

7.0 Summary and Conclusions 17

Appendix 1 - Aircraft Type by IATA Code 18

Appendix 2 - Gate Penetration Graphs 21

Contents


2

Community Noise Monitoring Saffron Walden

1.0 Overview

Campbell Associates were commissioned by London Stansted Airport to undertake

three months community noise monitoring to evaluate the impact of noise from Aircraft

from Stansted Airport and provide a baseline for future noise monitoring.

The monitoring dates were the 1st of November 2011 to the 27th of January 2012

The noise monitor was situated in Bridge End Gardens, See figure 1 where the yellow

pin mark identifies the location


3

The instrumentation conforming to IEC 61672 type one was fixed to a maintenance hut

in the corner of the formal gardens and the measurement microphone extended on a

pole above the roof. See figure 2. The noise monitor was located approximately

14.6km from London Stansted airport. See figure 3

Figure 2 Measurement Microphone position

Figure 3 Measurement location


4

2.0 Defining Aircraft Noise

To establish the noise impact of aircraft on the community the noise from Aircraft needs

to be separated from other noise. To do this the sound level data collected over the

three month period was analyzed to find patterns in the data, which could be attributed

to aircraft noise. To do this a threshold level of 53dBA and a time period of 8 seconds

was set. Any noise data which fits this criterion was identified and labeled as a ‘Noise

Event’.

The next stage was to attribute the noise event to individual aircraft arriving at, or

departing from London Stansted Airport. To do this a gate was defined (which can be

seen in figure 4) and all Aircraft which pass through the gate were identified by Aircraft

type, flight number and with a date and time stamp. With the date and time stamp it is

possible to correlate a noise event to an aircraft to give us ‘Aircraft Noise Events’.

Figure 4 – Gate to identify aircraft overflying Saffron Walden


5

The table in figure 5 below shows the number of noise events, aircraft noise events,

flights in flight plan passing over Saffron Walden and the correlation rate.

A Correlation rate of 55% is an acceptable rate for this monitoring project when the

distance from the airport is taken into account. Measurements where noise monitors

are closer to an airport will give greater correlation. This is because the sound level of

the aircraft is greater as they are flying lower over the noise monitor. This makes them

much easier to identify above other sounds in the vicinity of the noise monitor. The

sound level from aircraft overflying Saffron Walden on some days, especially when

there was high wind, was too close to background noise to be able to identify as aircraft

noise events.

Please note the study only includes Aircraft flying to, or departing from London

Stansted. Flights to and from other airports are not included.

Total noise events 11513

Aircraft Noise events 1593

Flights in flight plan 2905

Correlation rate 55%

Figure 5 –

Correlation of Aircraft Noise Events


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3.0 Flight Arrivals and Departures

During the measurement period the vast majority of movements over Saffron Walden

were arrivals. The breakdown is as follows with flight plan being the total movement and

aircraft events being those that could be identified as noise events:

Flight Plan

• Flight arrivals – 2878

• Flight departures - 27

Aircraft events

• Flight arrivals – 1,593

• Flight departures – 14


7

4.0 Number of Noise Events

The chart in figure 6 shows the number of aircraft noise events per day. From the graph

it can be seen that the number of events varies significantly from day to day. This is

mostly due to runway usage but also due to efficiency of the correlation of aircraft noise

events. On some days it was not possible to correlate noise events due to weather

conditions generating high background noise levels.

0

10

20

30

40

50

Nu

mb

ers

of

No

ise e

ven

ts e

ach

day

Figure 6: Numbers of Noise events


8

4.1 Number of Aircraft events per hour

Figure 7 shows the distribution of Aircraft per hour of the day. The aircraft events mainly

start at 7am which is associated with arrivals at the Airport. We can see from Arrivals

and departures in section 3.0 that arrivals are far more frequent in relation to Saffron

Walden.

0

20

40

60

80

100

120

140

160

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Nu

mb

er

of

No

ise e

ven

ts d

uri

ng

each

ho

ur

Hour of Day

Figure 7: Number of Aircraft Events per hour


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4.2 Aircraft Noise Events by Aircraft Type

Figure 8 shows the distribution of events by aircraft type. The majority of aircraft are

types 73H (Boeing 737-800) and 319 (Airbus 319). The Boeing 737-800 and Airbus

319 are the aircraft types used by Ryanair and Easyjet respectively and are two of the

major carriers operating from London Stansted.

0

100

200

300

400

500

600

700

800

900

1000

73H

319

733

M1

F

AT

7

320

73Y

74N

ER

3

76Y

74Y

AB

Y

CN

J

752

738

73W

77x

SW

M

CC

J

E9

0

142

AR

8

D38

DF

7

GS

5

321

762

76X

AP

F

CC

X

EM

2

GR

J

GS

4

744

763

75W

AB

6

AN

F

CL6

DF

3

E7

0

EP

3

F5

0

L45

L60

LO

H

LT

J

M8

3

P1

2

PA

2

nu

mb

er

of

Ev

en

ts

Aircraft type codes

Figure 8: Numbers of Aircraft noise events from different Aircraft types


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5.0 Maximum noise levels

During the measurement period the noise monitor also recorded the maximum sound

levels. For Aircraft monitoring this is measured with A weighting and a slow network

and is referred to as the LAS max

5.1 Maximum levels by aircraft type

For each Aircraft noise event this maximum level is also reported which can be seen in

Figure 9 below by aircraft type. The maximum levels range from 56dB to 68.2dB LAS max

and the most commonly used aircraft 73H and 319 had an average of maximum levels

of 61.8dB and 62.1dB LAS max respectively.

0

10

20

30

40

50

60

70

80

74N

AN

F

LO

H

GS

5

762

77x

AB

6

74Y

752

CC

J

F5

0

L45

142

M1

F

EM

2

319

73H

GR

J

76X

320

ER

3

744

738

AP

F

73W

AB

Y

AT

7

AR

8

321

P1

2

76Y

CC

X

73Y

733

D38

E9

0

E7

0

CN

J

CL6

EP

3

DF

7

PA

2

SW

M

GS

4

DF

3

L60

M8

3

LT

J

75W

763

No

ise

le

ve

l /

LA

S m

ax

dB

Aircraft type codes

Figure 9: Average value of maximum noise level arising from different Aircraft types


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5.2 Maximum levels by day

Figure 10 below shows the average of the maximum levels by day of the monitoring

period. Gaps in data were due to poor weather where aircraft noise events could not be

identified.

52

54

56

58

60

62

64

66

68

0 2 4 6 8 10121416182022242628303234363840424446485052545658606567697173757779818385

No

ise

le

ve

l /

LA

S m

ax

dB

Day of measurement

Figure 10: Average value of maximum noise levels of aircraft noise events


12

5.3 Maximum levels by hour of the day

Figure 11 shows the spread of maximum noise levels by hour of the day.

Please note the maximum noise levels are mostly dictated by the path of the aircraft

and how closely they overflew the noise monitor. The gate which can be seen from

figure 4 shows that the aircraft can be some distance from the monitor. The maximum

levels measured in this exercise should not be used as a means of establishing the

noisiest aircraft.

56

57

58

59

60

61

62

63

64

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

No

ise

le

ve

l / L

AS

ma

x d

B

hours of day

Figure 11: Average value of maximum noise levels of aircraft noise event per hour of day


13

Figure 12 displays the distribution of maximum aircraft noise events.

0

50

100

150

200

250

52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

Nu

mb

er

of

Ev

en

ts

Noise level / LASmax dB

Figure 12 : Statistical distribution of maximum noise levels of aircraft noise


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6.0 Noise Climate

6.1 LAeq average and L90 background noise

Figure 13 displays the noise climate at the monitoring location displayed by hour of the

day. This includes all noise for the complete monitoring period. It is expressed as an

Leq value which is the energetic average of all sound over each hourly period.

In addition there is an LA90 value plotted which is a statistical calculation on the sound

levels logged. The LA90 is the noise level which is exceeded for 90% of the time and is

a value which is commonly used as an indicator for background noise at a given

location.

20

25

30

35

40

45

50

55

60

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

No

ise

le

ve

l /

dB

A

Hour of Day

Figure 13: Noise climate total noise (Leq) and background noise (LA90)

hour by hour

LAeq LA90


15

6.2 Average noise, Aircraft Noise and Residual noise

Figure 14 displays the average (LAeq) levels by hour again but also displays the level

attributed to aircraft noise by hour. This is calculated by combining the aircraft noise

events during the monitoring period. This value is then subtracted from the total noise

to give a residual noise which is the level you would expect if the aircraft noise events

are removed.

Figure 14: Noise Climate showing average values for each hour of total noise,

aircraft noise and residual noise (LAeq)

Hour of Day

Aircraft Noise

Total Noise

Residual Noise

1 36.7 42.9 41.7

2 36.8 42.5 41.2

3 37.4 43.5 42.3

4 37.8 44.6 43.6

5 39.4 45.8 44.7

6 43.0 48.8 47.5

7 44.7 50.5 49.2

8 46.5 51.7 50.1

9 46.4 52.3 51.0

10 48.0 52.4 50.4

11 48.9 53.1 51.0

12 47.2 51.6 49.6

13 47.4 52.0 50.1

14 47.7 53.0 51.4

15 45.8 51.2 49.7

16 45.2 51.1 49.7

17 44.8 50.2 48.7

18 45.3 49.8 47.9

19 46.5 50.4 48.2

20 46.6 51.1 49.2

21 44.0 50.0 48.7

22 41.7 47.5 46.1

23 41.5 46.0 44.1

24 37.8 43.6 42.3


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6.3 Lden values

The table in figure 14 below shows the levels as expressed as an Lden value. The

Lden is a noise metric which is a 24 hour average (LAeq) normally calculated for an

annual period. It includes a 5 dB weighting for evening and a 10 dB weighting for night

periods. The periods are broken down as can be seen in table 14. The Lden is an

indicator which is being increasingly used as an expression of the long term noise

climate at a given location. This has been expressed in the table below for total noise,

aircraft noise and residual noise.

Total Noise – Lden 54.3 dB

Day 07.00 -19.00 = 51.8dB(A)

Evening 19.00-23.00 = 49.3dB(A)

Night 23.00 – 07.00 = 46.4dB(A)

Aircraft Noise – Lden 48.5 dB

Day 07.00 -19.00 = 46.8dB(A)

Evening 19.00-23.00 = 44.0dB(A)

Night 23.00 – 07.00 = 39.9dB(A)

Residual Noise – Lden 53.8 dB

Day 07.00 -19.00 = 50.2dB(A)

Evening 19.00-23.00 = 47.8dB(A)

Night 23.00 – 07.00 = 45.3dB(A)

Figure 14 – Lden values


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7.0 Summary and Conclusions

The community noise monitoring has been a useful exercise to establish:

The impact of aircraft noise from London Stansted Airport on Saffron Walden

It is possible to measure aircraft noise in Saffron Walden and correlate this with

aircraft associated to Stansted Airport.

A baseline, which can be used for any future noise monitoring in the Saffron

Walden community.


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Appendix 1 Aircraft Type by IATA Code

IATA Code

ICAO Code Manufacturer and aircraft type/ model

73H

B738 Boeing 737-800 (winglets) pax

319

A319 Airbus A319

AT7

AT72 Aerospatiale/Alenia ATR 72

733

B733 Boeing 737-300 pax

DH4

DH8D De Havilland Canada DHC-8-400 Dash 8Q

73Y

B733 Boeing 737-300 Freighter

M1F

MD11 McDonnell Douglas MD11 Freighter

320

A320 Airbus A320-100/200

74Y


ER3

E135 Embraer RJ135

CNJ

n/a Cessna Citation

142

B462 BAe 146-200 Pax

74N

747 - 800 (Freighter)

ABY

A306 Airbus Industrie A600-600 Freighter

738


GRJ

n/a Gulfstream Aerospace G-1159 Gulfstream II / III / IV / V

76Y


GS5

Gulfstream 5

CCJ

CL60 Canadair Challenger

E90

E190 Embraer 190

73W

B737 Boeing 737-700 (winglets) pax

76X


AR8

RJ85 Avro RJ85 Avroliner

CCX

GLEX Canadair Global Express

CL6

Challenger 604/605

DF3

DC3 Douglas DC-3 Freighter

77X


DF2

n/a Dassault (Breguet Mystere) Falcon 10 / 100 / 20 / 200 / 2000

752


EM2

E120 Embraer EMB.120 Brasilia

GS4

GLF4 Gulfstream 4

SWM

n/a Fairchild (Swearingen) SA26 / SA226 / SA227 Metro / Merlin / Expediter

14Z

B463 BAe 146 Freighter (-200QT & QC)

H25

n/a British Aerospace (Hawker Siddeley) HS.125

LRJ

n/a Gates Learjet

763


D38

D328 Fairchild Dornier Do.328

E70

E170 Embraer 170

EP1

Embraer Phenom 100

318

A318 Airbus A318

321

A321 Airbus A321-100/200

73C

737-300 (Winglets)

CJT

Cessna Jet

CN7

Cessna Citation 750x


19

F50

F50 Fokker 50

L45

Learjet 45

L60

Learjet 60

PA2

n/a Piper light aircraft - twin piston engines

722


735


73G


74L

N74S Boeing 747SP

75W

757-200 (Winglets)

APF

ATP - freighter

CCL

Challenger 600 Series

CJ2

Cesna citation CJ2

FRJ

J328 Fairchild Dornier 328JET

P12

Pilatus PC-12

SFF

SAAB 340 Freighter

332

A332 Airbus A330-200

63M

Boeing globemaster 3

744


762


A4F

A124 Antonov AN-124 Ruslan

AR1

RJ1H Avro RJ100 Avroliner

BE2

n/a Beechcraft twin piston engines

CGX

Global Express

CXL

DA5

Falcon 50

DAF

Dassant Falcon (Generic)

DF7

Falcon 7x

ER4

E145 Embraer RJ145 Amazon

ERJ

n/a Embraer RJ135 / RJ140 / RJ145

F27

F27 Fokker F.27 Friendship / Fairchild F.27

G20

Gulfstream galaxy 200

GS2

Gulfstream 2

GS3

Gulfstream 3

LOF

L188 Lockheed L-188 Electra Freighter

LOH

C130 Lockheed L-182 / 282 / 382 (L-100) Hercules

M83

MD83 McDonnell Douglas MD83

PR1

Premier 1


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Appendix 2 Gate Penetration Graphs for Saffron Walden

04 and 22 Departures (all 3 months)

04 and 22 Arrivals November 2011


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04 and 22 Arrivals December 2011

04 and 22 Arrivals January 2012

Community Noise Monitoring Saffron Walden · Saffron Walden Community Noise Monitoring 9 4.2...

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