Appendix 3.6     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
Scenario 1c / 2c		S76C+ Passing by along the flight path
	Closest Distance to Flight Path	S76C+
		Pass By
		(away)*
Talon Tower	250	82.9
Ka On	230	82.8
The Bauhinia	190	79.5
	Distance from noise source	S76C+
		Pass By
		(away)*
Sea View Mansion	350	80
Harmony Court	330	80
Hongway Garden	285	82
*worst case scenario
Closest distance between Talon Tower between the flight path was adopted as the reference distance
Scenario 2a:  Corrected Lmax Level at existing NSRs, dB(A) due to proposed helipad with corrected distance
	Distance to	S76C+
	New	Approach	Hovering		Hovering
	Helipad		to landing	Idling	to take off	Take Off
Talon Tower	432	76.7	80.6	77.2	78.6	80.5
Ka On	328	73.4	70.3	70.3	70.2	80.4
The Bauhinia	191	81.9	75.4	67.2	72.8	83.4
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 5 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.
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 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