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
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 66.6 66.6 22
Approach 74.5 74.5 75.4 75.4 32
Hovering* 77.5 77.5 78.4 68.4 30
Idling* 67.4 67.4 68.3 58.3 668
Hovering* 77.2 77.2 78.1 68.1 51
Take off 79.5 79.5 80.4 80.4 13
Pass By (away) 68.6 68.6 69.5 68.6 30
    846
Distance 213.0 (T1)
Corrected Distance 191.0  
Distance Correction 0.9  
     
Corrected Leq(helicopter) for a event = 66.6 (SPL1)  
     
No. of flights    
N = 11 (22 movements)  
Leq(4-hour) = 64.7        
Note:
* 10dB(A) deduction for screening effect from Shun Tak Building during idling / hovering