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 |
|
|
The
Bauhinia - (Based on the measured helicopter noise results at Harbour
Commercial Building) |
|
|
|
|
|
|
S76C+ |
|
|
|
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 |
|
|
|
|
|
846 |
|
Background Level |
0.0 |
|
|
|
|
|
Distance |
213.0 |
|
|
(T1) |
|
Corrected Distance |
222.0 |
|
|
|
|
Distance Correction |
-0.4 |
|
|
|
|
|
|
|
|
|
|
Corrected Leq(helicopter)
for a event = |
70.5 |
|
(SPL1) |
|
|
|
|
|
|
|
|
|
No.
of flights |
|
|
|
|
|
N = |
8 |
|
(16 movements)** |
|
|
Leq(4-hour)
= |
67.3 |
|
|
|
|
|
Note: |
|
** existing flight frequency
during 1900 to 2300 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|