| Appendix 3.7b Calculation of Helicopter Noise
at the Proposed Helipad, Leq (4 hours) During 1900 - 2300 hrs |
| Mode
1 - Approach from East and Take off to West |
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| The
Bauhinia - (Based on the measured helicopter noise results at Harbour
Commercial Building) |
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|
S76C+ |
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| Event |
LA |
LA w/o
bk |
LA with Distance Correction |
Corrected LA
with Screening effect |
Duration, s |
|
| Pass By (approach) |
66.8 |
66.8 |
67.7 |
67.7 |
50 |
|
| Approach |
74.9 |
74.9 |
75.8 |
75.8 |
27 |
|
| Hovering* |
79.4 |
79.4 |
80.3 |
70.3 |
30 |
|
| Idling* |
61.2 |
61.2 |
62.1 |
52.1 |
675 |
|
| Hovering* |
75.9 |
75.9 |
76.8 |
66.8 |
61 |
|
| Take off |
78.4 |
78.4 |
79.3 |
79.3 |
12 |
|
| Pass By (away) |
74.1 |
74.1 |
75.0 |
75.0 |
12 |
|
| |
|
867 |
|
| Background Level |
0.0 |
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| Distance |
213.0 |
|
|
(T1) |
|
| Corrected Distance |
191.0 |
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| Distance Correction |
0.9 |
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| Corrected Leq(helicopter)
for a event = |
66.0 |
|
(SPL1) |
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| No.
of flights |
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| N = |
11 |
|
(22 movements) |
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| Leq(4-hour)
= |
64.2 |
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| Note: |
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| *
10dB(A) deduction for screening effect from Shun Tak Building during idling /
hovering |
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