Appendix 3.6     Calculation of Lmax at the NSRs
(Flight Path - Approach from West and Take Off to East)
Scenario 1b:	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	83.7	84.9	77.9	83.7	77.1
Ka On	264	84.5	85.7	78.4	84.5	79.2
Harbour Commercial Building	213	81.7	83.5	78.5	84.1	83.6
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	82.5	83.7	76.7	82.5	75.9
Ka On	264	84.5	85.7	78.4	84.5	79.2
The Bauhinia	222	81.3	83.1	78.1	83.7	83.2
Scenario 1c / 2c		S76C+ Passing by along the flight path
	Closest Distance to Flight Path	S76C+
		Pass By
		(approach)*
Talon Tower	250	79.9
Ka On	230	79.8
The Bauhinia**	190	76.6
**worst case scenario for The Bauhinia was away mode
	Distance from noise source	S76C+
		Pass By
		(approach)*
Sea View Mansion	350	77
Harmony Court	330	77
Hongway Garden	285	79
*worst case scenario
Closest distance between Talon Tower between the flight path was adopted as the reference distance
Scenario 2b :  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	80.9	82.1	75.1	80.9	74.3
Ka On	328	82.6	78.8	71.5	77.6	77.3
The Bauhinia	191	82.6	74.4	69.4	75.0	84.5
Note:
1. 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
2. No screening effect is expected to Talon Tower for all modes of helicopter operation.
3. No screening effects is expected to the Bauhinia during take off mode of helicopter operation at the proposed helipad according to the flight path.
4. 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.
5. The above noise levels predicted in Scenario 1b assuming that the flight path is approaching from the west and take off to the east.
6. As the measurement data at Ka On during take off are similar to the case for the proposed helipad, no screening effect correction are applied in the noise levels for the take off mode.
Scenario 3b:  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	82.3	83.2	78.7
Ka On	328	84.0	81.6	80.9
The Bauhinia	191	84.0	79.9	85.4
*Worst case scenario
Scenario 4b:  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	83.2	84.3	78.5
Ka On	328	84.7	85.9	79.9
The Bauhinia	191	81.6	83.9	83.4
*Worst case scenario