Community Noise Monitoring Saffron Walden John Campbell Campbell Associates Ltd

Transcription

1 Community Noise Monitoring Saffron Walden John Campbell Campbell Associates Ltd

2 Contents Page Number 1.0 Overview Defining Aircraft Noise Flights Arrivals and Departures Number of Noise Events Number of aircraft events per hour Aircraft Noise Events by Aircraft Type Maximum noise levels Maximum levels by aircraft type Maximum levels by day Maximum levels by hour of the day Noise Climate LAeq average and L90 background noise Average noise, Aircraft Noise and Residual noise Lden values Summary and Conclusions 17 Appendix 1 - Aircraft Type by IATA Code 18 Appendix 2 - Gate Penetration Graphs 21 1

3 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 1 st of November 2011 to the 27 th of January 2012 The noise monitor was situated in Bridge End Gardens, See figure 1 where the yellow pin mark identifies the location 2

4 The instrumentation conforming to IEC 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 3

5 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 4

6 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. Total noise events Aircraft Noise events 1593 Flights in flight plan 2905 Correlation rate 55% Figure 5 Correlation of Aircraft Noise Events 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. 5

7 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 6

8 Numbers of Noise events each day Saffron Walden Community Noise Monitoring 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. Figure 6: Numbers of Noise events

9 Number of Noise events during each hour Saffron Walden Community Noise Monitoring 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. Figure 7: Number of Aircraft Events per hour Hour of Day 8

10 73H M1F AT Y 74N ER3 76Y 74Y ABY CNJ W 77x SWM CCJ E AR8 D38 DF7 GS X APF CCX EM2 GRJ GS W AB6 ANF CL6 DF3 E70 EP3 F50 L45 L60 LOH LTJ M83 P12 PA2 number of Events Saffron Walden Community Noise Monitoring 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 ) and 319 (Airbus 319). The Boeing and Airbus 319 are the aircraft types used by Ryanair and Easyjet respectively and are two of the major carriers operating from London Stansted Figure 8: Numbers of Aircraft noise events from different Aircraft types Aircraft type codes 9

11 74N ANF LOH GS x AB6 74Y 752 CCJ F50 L M1F EM H GRJ 76X 320 ER APF 73W ABY AT7 AR8 321 P12 76Y CCX 73Y 733 D38 E90 E70 CNJ CL6 EP3 DF7 PA2 SWM GS4 DF3 L60 M83 LTJ 75W 763 Noise level / LAS max db Saffron Walden Community Noise Monitoring 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 L AS 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 L AS max and the most commonly used aircraft 73H and 319 had an average of maximum levels of 61.8dB and 62.1dB L AS max respectively. Figure 9: Average value of maximum noise level arising from different Aircraft types Aircraft type codes 10

12 Noise level / LAS max db Saffron Walden Community Noise Monitoring 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. 68 Figure 10: Average value of maximum noise levels of aircraft noise events Day of measurement 11

13 Noise level / LAS max db Saffron Walden Community Noise Monitoring 5.3 Maximum levels by hour of the day Figure 11 shows the spread of maximum noise levels by hour of the day. Figure 11: Average value of maximum noise levels of aircraft noise event per hour of day hours of 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. 12

14 Number of Events Saffron Walden Community Noise Monitoring Figure 12 displays the distribution of maximum aircraft noise events. 250 Figure 12 : Statistical distribution of maximum noise levels of aircraft noise Noise level / LASmax db 13

15 Noise level / dba Saffron Walden Community Noise Monitoring 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. Figure 13: Noise climate total noise (Leq) and background noise (LA90) hour by hour LAeq LA Hour of Day 14

16 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

17 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 = 51.8dB(A) Evening = 49.3dB(A) Night = 46.4dB(A) Aircraft Noise Lden 48.5 db Day = 46.8dB(A) Evening = 44.0dB(A) Night = 39.9dB(A) Residual Noise Lden 53.8 db Day = 50.2dB(A) Evening = 47.8dB(A) Night = 45.3dB(A) Figure 14 Lden values 16

18 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. 17

19 Appendix 1 Aircraft Type by IATA Code IATA Code ICAO Code Manufacturer and aircraft type/ model 73H B738 Boeing (winglets) pax 319 A319 Airbus A319 AT7 AT72 Aerospatiale/Alenia ATR B733 Boeing pax DH4 DH8D De Havilland Canada DHC Dash 8Q 73Y B733 Boeing Freighter M1F MD11 McDonnell Douglas MD11 Freighter 320 A320 Airbus A /200 74Y B744 Boeing Freighter ER3 E135 Embraer RJ135 CNJ n/a Cessna Citation 142 B462 BAe Pax 74N (Freighter) ABY A306 Airbus Industrie A Freighter 738 B738 Boeing pax Gulfstream Aerospace G-1159 Gulfstream II / III / GRJ n/a IV / V 76Y B763 Boeing Freighter GS5 Gulfstream 5 CCJ CL60 Canadair Challenger E90 E190 Embraer W B737 Boeing (winglets) pax 76X B762 Boeing Freighter AR8 RJ85 Avro RJ85 Avroliner CCX GLEX Canadair Global Express CL6 Challenger 604/605 DF3 DC3 Douglas DC-3 Freighter 77X B762 Boeing Freighter Dassault (Breguet Mystere) Falcon 10 / 100 / 20 / DF2 n/a 200 / B752 Boeing pax EM2 E120 Embraer EMB.120 Brasilia GS4 GLF4 Gulfstream 4 Fairchild (Swearingen) SA26 / SA226 / SA227 Metro SWM n/a / Merlin / Expediter 14Z B463 BAe 146 Freighter (-200QT & QC) H25 n/a British Aerospace (Hawker Siddeley) HS.125 LRJ n/a Gates Learjet 763 B763 Boeing pax D38 D328 Fairchild Dornier Do.328 E70 E170 Embraer 170 EP1 Embraer Phenom A318 Airbus A A321 Airbus A /200 73C (Winglets) CJT Cessna Jet CN7 Cessna Citation 750x 18

20 F50 F50 Fokker 50 L45 Learjet 45 L60 Learjet 60 PA2 n/a Piper light aircraft - twin piston engines 722 B722 Boeing pax 735 B735 Boeing pax 73G B737 Boeing pax 74L N74S Boeing 747SP 75W (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 A M Boeing globemaster B744 Boeing pax 762 B762 Boeing pax 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 19

21 Appendix 2 Gate Penetration Graphs for Saffron Walden 04 and 22 Departures (all 3 months) 04 and 22 Arrivals November

22 04 and 22 Arrivals December and 22 Arrivals January