Appendix 3.7b Calculation of Helicopter Noise
at the Proposed Helipad, Leq (4 hours) During 1900 - 2300 hrs |
Mode
2 - Approach from West and Take off to East |
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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 |
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Pass By (approach) |
65.7 |
65.7 |
66.6 |
66.6 |
22 |
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Approach |
74.5 |
74.5 |
75.4 |
75.4 |
32 |
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Hovering* |
77.5 |
77.5 |
78.4 |
68.4 |
30 |
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Idling* |
67.4 |
67.4 |
68.3 |
58.3 |
668 |
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Hovering* |
77.2 |
77.2 |
78.1 |
68.1 |
51 |
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Take off |
79.5 |
79.5 |
80.4 |
80.4 |
13 |
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Pass By (away) |
68.6 |
68.6 |
69.5 |
68.6 |
30 |
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846 |
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Background Level |
0.0 |
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Distance |
213.0 |
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(T1) |
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Corrected Distance |
191.0 |
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Distance Correction |
0.9 |
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Corrected Leq(helicopter)
for a event = |
66.6 |
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(SPL1) |
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No.
of flights |
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N = |
11 |
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(22 movements) |
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Leq(4-hour)
= |
64.7 |
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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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