| Appendix 3.7a Calculation of Helicopter Noise
at the Existing 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 |
|
| Pass By (approach) |
65.7 |
65.7 |
65.3 |
65.3 |
22 |
|
| Approach |
74.5 |
74.5 |
74.1 |
74.1 |
32 |
|
| Hovering |
77.5 |
77.5 |
77.1 |
77.1 |
30 |
|
| Idling |
67.4 |
67.4 |
67.0 |
67.0 |
668 |
|
| Hovering |
77.2 |
77.2 |
76.8 |
76.8 |
51 |
|
| Take off |
79.5 |
79.5 |
79.1 |
79.1 |
13 |
|
| Pass By (away) |
68.6 |
68.6 |
68.2 |
68.6 |
30 |
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| |
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|
846 |
|
| Background Level |
0.0 |
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| Distance |
213.0 |
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|
(T1) |
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| Corrected Distance |
222.0 |
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| Distance Correction |
-0.4 |
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| Corrected Leq(helicopter)
for a event = |
70.5 |
|
(SPL1) |
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| No.
of flights |
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| N = |
11 |
|
(22 movements)** |
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| Leq(4-hour)
= |
68.6 |
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| Note: |
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| **
current maximum allowable flight frequency during 1900 to 2300 |
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