the naroghid wind farm airservices australia proponent...

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The Naroghid Wind Farm

Airservices Australia

Proponent : Naroghid Wind Farm Pty Ltd

AVIATION IMPACT STATEMENT

07 JUNE, 2017.

Naroghid Wind Farm

R. A. Gower MIEAust. of 13.

1. Author's Name and Address

Richard Gower M.I.E. Aust.

72 – 74 Boundary Road,

Gruyere, Vic. 3770.

2. Qualifications and Experience.

Details of the author's qualifications and experience are given in Appendix 1.

3. Scope.

3.1 Instructions

The author's instructions from Wind Farm Developments Pty Ltd on behalf of Naroghid Wind

Farm Pty Ltd, the Proponent, were to prepare an aviation impact statement in response to the

criteria in AirServices Australia's outline document dated January, 2017.

4. Factual Information.

(a) The Naroghid wind farm was approved by the Minister of Planning in August, 2006. The

current work is directed to re-consenting for a decrease in the number of turbines from 22

to 12 and an increase in the tip height from 125m AGL to 180m AGL along with an

increase in blade radius of up to 70m and an allowable tower height of up to 110m AGL.

(b) As part of the Aviation Impact Statement preliminary work, the southernmost turbine

location has been deleted due to the combination of both its distance from the Cobden

aerodrome and from the runway 36 extended centre line.

(c) The number of turbines for the re-consenting planning application has therefore been

reduced from 13 to 12 as a result of the risk assessment for aviation.

Naroghid Wind Farm


5. Response to AIS Criteria.

5.1 Airspace Procedures.

(1) Obstacles.

The positions of the turbines are summarised in the following table.

Latitudes and Longitudes are provided in WGS84, correct to 0.1 arc second; elevations are taken from

Google Earth, in feet, and converted to metres, and are thus correct to 0.3 m, assuming the interpolation error

between contours is negligible.

Turbine/Obstacl

e Number

Latitude

(WGS84)

Longitude

(WGS84)

Ground

Elevation

m AMSL

Maximum Tip

Elevation

m AMSL

Maximum Tip

Elevation

FT AMSL

1 -38°16"54.2" 143°1"40.9" 186.5 399.5 1,311

2 -38°17"1.7" 143°1"52.9" 185.9 398.9 1,309

3 -38°16"59.7" 143°2"18.9" 199.3 412.3 1,353

4 -38°16"36.1" 143°2"41.3" 209.1 422.1 1,385

5 -38°16"49.4" 143°2"53.9" 212.4 425.4 1,396

6 -38°17"12.6" 143°2"44.6" 205.1 418.1 1,372

7 -38°17"10.1" 143°3"11.8" 203.9 416.9 1,368

8 -38°16"55.1" 143°3"38.1" 205.1 418.1 1,372

9 -38°17"6.7" 143°3"52.5" 204.2 417.2 1,369

10 -38°17"18.9" 143°3"30.3" 200.3 413.3 1,356

11 -38°17"44.7" 143°3"23.2" 194.8 407.8 1,371

12 -38°17"28.8" 143°3"12.9" 203.3 416.3 1,366

Given that:

the LSALT on the nearest airway, W635 is 2500FT AMSL

the highest terrain at the wind farm site is 732FT

the maximum obstruction height below the 1000FT LSALT buffer is 768FT (234m).

The maximum tip height in the current proposal is 180m AGL.

(2) Drawings.

The following charts, related to Warrnambool Aerodrome, are at appendix 4.

Chart Name Date AERODROME CHART 25-May-2017 (Am 151)

RNAV-Z (GNSS) RWY 13 25-May-2017 (Am 151)

RNAV-Z (GNSS) RWY 31 25-May-2017 (Am 151)

The 1:250,000 topographical chart is at appendix 5.

http://www.airservicesaustralia.com/aip/pending/dap/WBLAD01-151.pdf

http://www.airservicesaustralia.com/aip/pending/dap/WBLGN02-151.pdf

http://www.airservicesaustralia.com/aip/pending/dap/WBLGN01-151.pdf

Naroghid Wind Farm


(3) Aerodromes.

The following aerodromes are located within 30NM of the proposed wind farm:

(a) Warrnambool Aerodrome (YWBL) is registered and has a 1372m bitumen runway

aligned 13/31 and a 1069 gravel runway aligned 04/22. It is located 27NM from the site

and is therefore outside the 25NM MSA radius. It does however lie within the 30NM

radius from YWBL ARP.

No obstacle associated with the proposal would penetrate the OLS for YWBL.

There are six (6) towers in the general vicinity as published in ERSA. These include a

549FT unlit tower, at 4NM SW of the aerodrome and a 394FT unlit tower 2.8NM to the

NNE.

(b) Cobden Aerodrome (YCDE) is uncertified and has a 900m bitumen runway 15m wide

aligned 18/36. The RWY 18 threshold is located 2.63 km (1.4NM) from the nearest

proposed wind turbine (#11).

There is no OLS applicable to this aerodrome.

(4) Air Routes.

There is no impact on existing air routes. Those in the vicinity of the site are shown below. W635 is the

only route of significance and the tip height of the highest turbine is 1104FT below the lowest safe altitude

(LSALT) of 2500FT

ROUTE NUMBER Associated Waypoint

Names Published Route Lowest Safe Altitude (LSALT) (ft)

V126 YWE and Portland 3000

V279 Portland to STONE 2700

V279 STONE to WENDY 3000

W571 WBL to STONE 2700

W571 STONE TO YWE 3000

W741 Hamilton to WBL 2900

J43 WBL to GRACY 18000

W635 AVV to WBL 2500

Naroghid Wind Farm


(5) Airspace.

The proposed site is contained wholly within G airspace.

5.2 Navigation/Radar.

By calculation, the proposed wind farm is significantly beyond the theoretical radar horizon from

both the Mt Macedon and Gellibrand Hill sites.

The calculated figures are shown in the table below and are derived from the formula:

D = K√(h1–h2)

where K = 1.23i

D is the distance to the radar horizon in NM and

h1 and h2 are the transmitter and target heights in FT AMSL.

The formula is quoted extensively in ICAO Guidance Material on Surveillanceii and also in

Introduction to Radar Systems – Skolnickiii

The maximum tip height of 1,396FT AMSL (turbine #5) is used in calculating the following:

Site Site Elevation Distance –

Site to Wind Farm Radar Horizon

Gellibrand Hill Primary Radar

<222 m AHD 729FT AMSL

174 km 94NM

31NM

Gellibrand Hill Secondary Radar

<222 m AHD 729FT AMSL

174 km 94NM

31NM

Mt Macedon Secondary Radar

1043 m AHD 3422FT AMSL

166 km 90NM

55NM

(1) Dead zones.

No probability due to the distance of the site beyond the radar horizon.

(2) False Target Analysis.

No probability due to the distance of the site beyond the radar horizon.

(3) Target Positional Accuracy.

Not applicable.

(4) Probability of Detection.

Not applicable.

(5) Radar Coverage Implications.

No known implications.

Naroghid Wind Farm


6. Declaration.

I have made all the inquiries that I believe are desirable and appropriate and no

matters of significance which I regard as relevant have, to my knowledge, been

omitted.

Signed

07 June, 2017.

Naroghid Wind Farm


7. Appendices.

Appendix 1 - QUALIFICATIONS AND EXPERIENCE OF THE AUTHOR.

Engineering

The author holds electrical and electronic engineering qualifications appropriate to the grade

of member of the Institution of Engineers Australia.

Engineering experience includes:

over 55 years technical support experience on aircraft avionics, electrical, fuel and

hydraulic systems on piston, turboprop and jet transport aircraft.

over 35 years experience as an aircraft design signatory under CAR Reg. 40/41 and

CAR 35/36 both as an individual and on behalf of Ansett Airlines and Ansett

Engineering Services.

Operational.

The author has 57 years of flying experience and has logged 11,000 flying hours and holds a:

commercial pilots licence (multi-engine, land and sea)

Grade 1 (A grade) flight instructor rating,

CASA Flight Examiner approval.

RFACA Master Instructor Certificate.

flight instructor training approval.

low-level aerobatic approval.

instructor training approval in aerobatics and formation flying.

Operational and airspace experience includes:

Chief Pilot and Chief Flying Instructor of Royal Victorian Aero Club, Coldstream

Flying School and Yarra Valley Flight Training.

Industry Convenor of the Victorian Regional Airspace and Procedures Advisory

Committee (RAPAC) for six (6) years and a member for 37 years.

In 2006, under contract to CASA, revised and reorganised the layout of the CASA

VHF Flight Guide.

Contact details:

tel 0418 358 250

fax (03) 9739 0121

email [email protected]

Naroghid Wind Farm


Appendix 2 – Acronyms & Abbreviations.

Acronyms and abbreviations used in this report, together with their meaning, are included in the

following table.

AC Advisory Circular – a CASA document in support of a given regulation.

AGL Above Ground Level

AHD Australian Height Datum

AIP Aeronautical Information Publication

AMSL Above Mean Sea Level (similar meaning to AHD)

CAR Civil Aviation Regulation (-1988)

CASR Civil Aviation Safety Regulation (-1998)

DAP Departure and Approach Procedures (part of the AIP)

ERSA Enroute Supplement Australia (a combined Airservices & Defence document)

FT feet

ICAO International Civil Aviation Organisation

IFR Instrument Flight Rules

IMC Instrument Meteorological Conditions

LSALT Lowest Safe Altitude

m Metre or Metres

MOC Minimum Obstacle Clearance

MOS CASA Manual of Standards

MSA Minimum Sector Altitude

NASAG National Airports Safeguarding Advisory Group – (a CASA consultation group).

NASF National Airports Safeguarding Framework

OLS Obstacle Limitation Surface

PANS-OPS Procedures for Air Navigation Services – Operations (an ICAO document)

RWY Runway

SFC Surface

VFR Visual Flight Rules

VMC Visual Meteorological Conditions

WTG Wind Tower Generator

Naroghid Wind Farm


Appendix 3 – Calculation of Radar Horizon From Terrain Data.

The following is a calculation of the radar horizon based on the topography. It does

not consider radar energy diffraction due to atmosphere influence but does however

consider the height of the intermediate terrain.

Airservices Australia have provided locations and elevations of the relevant primary and secondary radars.

Publically available mapping software (Google Earth, and Geoscience Australia’s ELVIS) have been used to

assess whether the proposed wind farm has any line of sight contact with those radars.

The first assessment required according to the EURO Guidelines is reproduced below:

The first assessment that shall take place is to determine whether or not any part of the

turbine will be within the line of sight of the radar (i.e. from the electrical centre of the

radar antenna). If the turbines are located in a way that does not affect the surveillance

sensor performance (e.g. the turbines are fully ‘hidden’ from the sensors by terrain or

the turbines are located further away than the radar instrumented range), then consent

for the development can be approved. However if a part of the wind turbine (e.g. a

blade) can be in radar line of sight then there is potential for an impact upon the radar.

This assessment indicates that terrain intercepts the path at approximately 50NMl. The following is a

trigonometric, line of sight analysis based on a turbine tip height of 234m on the highest point of terrain on

the site.

The line of sight assessment considers both the Earth’s curvature but not any additional range due to

atmospheric refraction as does the formula quoted in 5.2 above. It does however consider height of

intermediate terrain between the radar sites and the wind farm.

The following calculations indicate that the proposed wind turbines would be not visible to the radars at

Gellibrand Hill or Mt Macedon.

Assessing first the Gellibrand Hill radars, the locations are mapped using Geoscience

Australia’s Elevation Information System: ELVIS, as shown in Figure 9. This interface

shows the height above mean sea level at a given distance from the radar. According to

Geoscience Australia, the uncertainty is ±5 m.

Screenshot from Geoscience Australia’s ELVIS tool, showing the profile from the Mt Macedon Radar Location.

Naroghid Wind Farm


The Earth’s curvature can be accounted for by considering the Earth as a circle with radius, r, 6371 km.

Thus, setting the radar as the origin, in two-dimensional Cartesian co-ordinates, the effect of the Earth’s

curvature is given by the equation of a circle, where x is the distance co-ordinate, and y is the height co-

ordinate, each given in kilometres:

Then, the terrain height above mean sea level at a distance x from the origin is y’. Thus the

effective height can be mapped with respect to the Earth’s curvature such that:

However, the map length from the Radar location R to the Wind Farm location W, is based on mean sea

level, and thus refers to an arc length. The arc length is thus known, allowing the arc angle to be computed,

and related back to the Cartesian x co-ordinate as follows:

|

Various points have been plotted in the diagram below. To determine whether a clear line of

sight exists between the radars and the wind farm, it must be established that there is no

terrain cutting the path.

In the following figures, the left most point represents the radar, and the final point (farthest

to the right) represents the maximum tip height any wind farm structure will intrude into the

1000FT LSALT buffer for W635 (1500 feet AMSL). Thus, the orange line represents the

line of sight between the radar and wind farm. It can be seen that two points, nominally 50

km from the radar, are plotted above this line. This implies that there is no line of sight

between the wind farm and the Mt Macedon radars.

Naroghid Wind Farm


Appendix 4 – DAP Charts for Warrnambool (YWBL).

Naroghid Wind Farm


Naroghid Wind Farm


Appendix 5 – 1:250,000 Chart Relating to Proposed Site.

i The constant K reduces with frequency. It is commonly quoted as 1.4 in references to VHF radio range in the aeronautical VHF

band but as 1.23 at radar frequencies.

ii ICAO EUR Doc. 11 (2016).

iii Library of Congress card number 61-17675.

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