Appendix 3.8     Calculation of Lmax at the NSRs
(Flight Path - Approach from East and Take Off to West)
Scenario 1a: S76C+ operated at Existing Helipad
Table 1.1: Measured Lmax Level, dB(A) from Existing Helipad
             
  Distance to S76C+ (w/o background)
  Existing Approach Hovering   Hovering  
  Helipad   to landing Idling to take off Take Off
Wayson 312 79.5 83.4 80.0 81.4 83.3
Ka On 264 75.3 77.2 77.2 77.1 82.3
Harbour Commercial Building 213 81.0 84.5 76.3 81.9 82.5
           
Table 1.2: Corrected Lmax Level on existing NSRs, dB(A) due to Existing Helipad with corrected distance
             
  Distance to S76C+
  Existing Approach Hovering   Hovering  
  Helipad   to landing Idling to take off Take Off
Talon Tower 358 78.3 82.2 78.8 80.2 82.1
Ka On 264 75.3 77.2 77.2 77.1 82.3
The Bauhinia 222 80.6 84.1 75.9 81.5 82.1
Table 1.3: Noise Certification Levels - S92 vs S76C+*
  S76C+ S92 Delta
Take off      
Left Mic 83.3 80.8 -2.5
Center Mic 83.2 83.3 0.1
Right Mic 80.8 80.7 -0.1
       
Approach      
Left Mic 79.3 82.2 2.9
Center Mic 87.6 87.8 0.2
Right Mic 87.7 86.8 -0.9
*ref: See Appendix 3.3
Scenario 1c / 2c / 2f S76C+ / S92 Passing by along the flight path
       
  Closest Distance to Flight Path S76C+ S92
  Pass By Pass By
  (away)*  
Talon Tower 250 82.9 83.0
Ka On 230 82.8 82.9
The Bauhinia 190 79.5 79.6
       
  Distance from noise source S76C+ S92
  Pass By Pass By
  (away)*  
Sea View Mansion 350 80 80
Harmony Court 330 80 81
Hongway Garden 285 82 82
*worst case scenario
Closest distance between Talon Tower between the flight path was adopted as the reference distance
Scenario 2a & 2d:  Corrected Lmax Level at existing NSRs, dB(A) due to proposed helipad with corrected distance
                       
  Distance to S76C+ S92
  New Approach Hovering Hovering   Approach Hovering Hovering  
  Helipad   to landing Idling to take off Take Off   to landing Idling to take off Take Off
Talon Tower 432 76.7 80.6 77.2 78.6 80.5 79.6 83.5 80.1 78.7 80.6
Ka On 328 73.4 70.3 70.3 70.2 80.4 76.3 73.2 73.2 70.3 80.5
The Bauhinia 191 81.9 75.4 67.2 72.8 83.4 84.8 78.3 70.1 72.9 83.5
Note:
1. The above noise levels predicted in Scenario 1a assuming that the flight path is approaching from the east and take off to the west.
2. No screening effect is expected to Talon Tower for all modes of helicopter operation.
3. Screening effect is expected on Ka On when the helicopter is in idling & hovering mode at the proposed helipad. Attenuation of 10 dB(A) for idling & hovering are applied to the noise levels
4.  As the measurment data at Ka On during approach mode are similar to the case for the proposed helipad, no screening correction are applied in the noise levels for approach mode.
5. No screening effects is expected to the Bauhinia during approach mode of helicopter operation at the proposed helipad according to the flight path.
6. Screening effect is expected on the Bauhinia when the helicopter is in idling and hovering mode at the proposed helipad.  Attenuation of 10 dB(A) for idling & hovering are applied to the noise levels.
7. +2.9 dB(A) was added to the Lmax of S76C+ during approach, hovering to landing and idling for the correction to S92
8. +0.1 dB(A) was added to the Lmax of S76C+ during hovering to take off and take off for the correction to S92
Scenario 3a / 3c: One S76C+ idling at Existing Helipad and and One S76C+ / S92 operated at New Helipad
Scenario 3a:  Cumulative impact (Lmax) when  one S76C+ Idling on existing helipad and one S76C+ Approach / Hovering / Takeoff on proposed helipad
  Distance to      
  New   Lmax, dB(A)  
  Helipad Approach Hovering* Takeoff
Talon Tower 432 80.9 82.8 82.7
Ka On 328 78.7 78.0 82.1
The Bauhinia 191 82.9 78.7 84.2
*Worst case scenario
Scenario 3c:  Cumulative impact (Lmax) when  one S76C+ Idling on existing helipad and one S92 Approach / Hovering / Takeoff on proposed helipad
  Distance to      
  New   Lmax, dB(A)  
  Helipad Approach Hovering* Takeoff
Talon Tower 432 82.2 84.7 82.8
Ka On 328 79.8 78.7 82.2
The Bauhinia 191 85.4 80.3 84.2
*Worst case scenario
Scenario 4a / 4c: One S76C+ operated at Existing Helipad and One S76C+ / S92 idling at New Helipad
Scenario 4a:  Cumulative impact (Lmax) when  one S76C+ Approach / Hovering / Takeoff on existing helipad and one S76C+ Idling on proposed helipad
  Distance to      
  New   Lmax, dB(A)  
  Helipad Approach Hovering* Takeoff
Talon Tower 432 80.8 83.4 83.3
Ka On 328 76.5 78.0 82.6
The Bauhinia 191 80.8 84.2 82.3
*Worst case scenario
Scenario 4c:  Cumulative impact (Lmax) when  one S76C+ Approach / Hovering / Takeoff on existing helipad and one S92 Idling on proposed helipad
  Distance to      
  New Lmax, dB(A) Lmax, dB(A) Lmax, dB(A)
  Helipad Approach Hovering* Takeoff
Talon Tower 432 82.3 84.3 84.2
Ka On 328 77.4 78.7 82.8
The Bauhinia 191 81.0 84.3 82.4
*Worst case scenario