Assessment ScoreCard – 31 Day

Assessment Scorecard headlines

All Assessments are based on an ambient background noise of 40 decibels i.e. a quiet residential area. If your property is located near to a busy road i.e. 70-75 decibels, the noise impact from aircraft will be significantly reduced, whilst the road remains busy.

Note: Airborne aircraft noise is typically in the range of 45dB - 65dB for heights below 26,000 feet and for a duration of 30-50 seconds. Whereas the average car, bus or HGV the duration is only a few seconds.

Date of survey

29/05/2023 19:14:21

UK Postcode

LETCHWORTH-SOUTH-WEST-3M , HERTFORDSHIRE , SG6 3ND

Baseline geo-coordinates

51.9672 , -0.231124

Survey type

31 days prior to: 29-May-2023 @17:59:05

Assessment band

FREQUENT

Assessment actual value

13.47

Assessment description

Sound equates to an "A" road or a busy "B" road i.e. regular traffic that will be noticeable at peak times which includes evenings and weekends. Location is on a primary flight corridor or flight route or in a flight holding stack area. At times there will be multiple flight occurrences within the same hour, typically between 4-10. Some of the flights will be below 7000 feet.

Band range

Lower: 12.0 --> Upper: 16.0

Volumes, Height bands, and Intensity.

For Assessment / Daily Avg. / Hourly Avg.

Count of ALL flights

5,794 / 186.9 / 11.0 ❌ (3,197)

Flights above 26k feet.

1,148 / 37.0 / 2.2 ❌ (760)

Flights between 16k and 26k feet

414 / 13.4 / 0.8 ❌ (349)

Flights between 13k and 15k feet

365 / 11.8 / 0.7 ❌ (178)

Flights between 7k and 12k feet

2,485 / 80.2 / 4.7 ❌ (547)

Flights between 6k and 7k feet

110 / 3.5 / 0.2 ✔

Flights between 5k and 6k feet

455 / 14.7 / 0.9 ❌ (229)

Flights between 4k and 5k feet

590 / 19.0 / 1.1 ❌ (266)

Flights between 3k and 4k feet

75 / 2.4 / 0.1 ✔

Flights below 3k feet

152 / 4.9 / 0.3 ✔

4 or more flights per hour

506 / 16.3 ❌ (204)

9 or more flights per hour

243 / 7.8 ❌ (77)

Departures between 1.5k and 15k feet

2,543 / 82.0 / 4.8 ❌ (407)

Time and Sleep Analysis

For Assessment / Daily Avg. / Hourly Avg.

Between Midnight and 1am

76 / 2.5

Between 1am and 2am

43 / 1.4

Between 2am and 3am

27 / 0.9

Between 3am and 4am

32 / 1.0

Between 4am and 5am

12 / 0.4

Between 5am and 6am

15 / 0.5

Between 6am and 7am

255 / 8.2

Between 7am and 8am

455 / 14.7

Between 8am and 9pm

4,470 / 144.2 / 10.3

Between 10pm and 11pm

182 / 5.9

Between 11pm and Midnight

149 / 4.8

Other Noise Disturbance, Vibration and Emissions factors

Avg time in seconds an aircraft remained in the airspace bubble

49 ❌ (30)

Percentage of overflying occuring Out-Of-Hours and at Weekends

49 ❌ (44)

Minimum avg. distance in miles

1.55

Number of possible disruptions by; day / out-of-hours / hour

137.0 / 68.0 / 7.2 ❌ (68)

Flight holding stack identified?

Yes ❌

Altitude for all flights

14,925 ❌ (17,611)

Altitude of departures between 1.5k and 15k feet

9,847 ✔

Altitude of flights below 20k feet

9,043 ✔

Busiest times of day
(Distruption: 0 - low, 25+ high)

Day of week, time, frequency and number of flight events.

22.40

Saturdays between 7:00 and 8:00- 4 time(s) in 4 weeks. Approx:14 flight events.

20.20

Mondays between 7:00 and 8:00- 4 time(s) in 4 weeks. Approx:12 flight events.

16.20

Saturdays between 14:00 and 15:00 - 4 time(s) in 4 weeks. Approx:10 flight events.

15.50

Mondays between 8:00 and 9:00- 4 time(s) in 4 weeks. Approx:11 flight events.

15.30

Sundays between 18:00 and 19:00 - 4 time(s) in 4 weeks. Approx:10 flight events.

14.70

Sundays between 17:00 and 18:00 - 4 time(s) in 4 weeks. Approx:9 flight events.

14.60

Saturdays between 13:00 and 14:00 - 4 time(s) in 4 weeks. Approx:9 flight events.

14.50

Sundays between 9:00 and 10:00- 4 time(s) in 4 weeks. Approx:9 flight events.