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
Ka On Building - (Based on the measured helicopter noise results at Ka On Building)
      S76C+    
Event LA LA w/o bk LA with Distance Correction Corrected LA with Screening effect Duration, s
Pass By (approach) 72.9 72.9 72.9 72.9 22
Approach 79.1 79.1 79.1 79.1 32
Hovering 81.1 81.1 81.1 81.1 30
Idling 63.5 63.5 63.5 63.5 668
Hovering 77 77.0 77.0 77.0 51
Take off 73.9 73.9 73.9 73.9 13
Pass By (away) 66 66.0 66.0 66.0 30
    846
Distance 264.0 (T1)
Corrected Distance 264.0  
Distance Correction 0.0  
     
Corrected Leq(helicopter) for a event = 71.3 (SPL1)  
     
No. of flights    
N = 11 (22 movements)**  
Leq(4-hour) = 69.4        
Note:
** current maximum allowable flight frequency during 1900 to 2300