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

28/05/2023 18:04:23

UK Postcode

LETCHWORTH-SOUTH-WEST , HERTFORDSHIRE , SG6 3ND

Baseline geo-coordinates

51.9661 , -0.231118

Survey type

31 days from the 1st date shown in the Evidence table below .

Assessment band

INTERMITTENT

Assessment actual value

6.10

Assessment description

Sound equates to a "C" road or an active country lane i.e. irregular traffic volumes. Location is on a flight route as opposed to a flight corridor. Some of the flights will be below 7000 feet and could occur at evenings and weekends.

Band range

Lower: 4.0 --> Upper: 7.0

Volumes, Height bands, and Intensity.

For Assessment / Daily Avg. / Hourly Avg.

Count of ALL flights

1,534 / 49.5 / 2.9 ✔

Flights above 26k feet.

327 / 10.5 / 0.6 ✔

Flights between 16k and 26k feet

113 / 3.6 / 0.2 ✔

Flights between 13k and 15k feet

84 / 2.7 / 0.2 ✔

Flights between 7k and 12k feet

672 / 21.7 / 1.3 ❌ (490)

Flights between 6k and 7k feet

36 / 1.2 / 0.1 ✔

Flights between 5k and 6k feet

106 / 3.4 / 0.2 ✔

Flights between 4k and 5k feet

161 / 5.2 / 0.3 ✔

Flights between 3k and 4k feet

22 / 0.7 / 0.0 ✔

Flights below 3k feet

13 / 0.4 / 0.0 ✔

4 or more flights per hour

104 / 3.4 ✔

9 or more flights per hour

1 / 0.0 ✔

Departures between 1.5k and 15k feet

621 / 20.0 / 1.2 ❌ (413)

Time and Sleep Analysis

For Assessment / Daily Avg. / Hourly Avg.

0 AM

23 / 0.7

1 AM

16 / 0.5

2 AM

10 / 0.3

3 AM

15 / 0.5

4 AM

5 / 0.2

5 AM

7 / 0.2

6 AM

54 / 1.7

7 AM

120 / 3.9

8 AM to 9 PM

1,172 / 37.8 / 2.7

10 PM

60 / 1.9

11 PM

42 / 1.4

Other Noise Disturbance, Vibration and Emissions factors

Time in seconds an aircraft existed in the airspace bubble

17 ✔

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

43 ✔

Minimum avg. distance in miles

0.46

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

26.0 / 11.0 / 1.4 ✔

Flight holding stack identified?

No

Altitude for all flights

15,200 ❌ (16,276)

Altitude of departures between 1.5k and 15k feet

10,051 ✔

Altitude of flights below 20k feet

9,015 ✔

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

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

6.88

Friday @ 17:00 - 4 time(s) in 4 weeks. Approx:5 flight events.

6.63

Friday @ 8:00 - 4 time(s) in 4 weeks. Approx:5 flight events.

5.88

Saturday @ 7:00 - 4 time(s) in 4 weeks. Approx:4 flight events.

5.38

Friday @ 6:00 - 4 time(s) in 4 weeks. Approx:4 flight events.

4.38

Friday @ 13:00 - 4 time(s) in 4 weeks. Approx:3 flight events.

3.88

Friday @ 11:00 - 4 time(s) in 4 weeks. Approx:3 flight events.