The concern related to the approval by the airport owner for a contractor to erect a 45 metre NBN communication tower which would enter the OLS of the airport
The reporter expressed a safety concern in relation to the erection of a 45 metre [above ground level] communications tower on the western approach to [location] Airport.
The reporter advised that NBN Co have proposed building a 45 metre high communications tower which will be placed on the western approach to [location] airport. It is reported that the tower will infringe the OLS area around the airport.
CASA has advised the council that this tower presents as a hazardous object in relation to Regulations 139.370(1) of the Civil Aviation Safety Regulations 1998. The [location] airport chief executive officer and the [location] shire council’s professional officers have both also recommended that the application should be refused.
The [location] shire council has rejected this advice and has approved the tower provided that NBN Co will provide indemnity against damage claims in the event of an aviation accident. This provision indicates that the council is aware that the tower is a real threat to the safety of passengers using [location] Airport.
Why should the tower not be relocated to an area that does not affect the safety of the travelling public?
Airservices considers that the primary safety issue raised in the REPCON relates to the legislative/regulatory head of power to protect against the safety risk associated with the proposed tower, and suggests that the report be referred to CASA and the Department of Infrastructure and Regional Services for a response.
Council received a development application in 2014 from [company], on behalf of the National Broadband Network Co, to erect a telecommunications facility comprising a 45 metre high lattice tower and ancillary equipment at [address].
As part of the planning assessment of this application it was confirmed that the proposed tower would infringe the [location] Aerodrome Obstacle Limitation Surface (OLS). The proposal was subsequently referred to CASA, Airservices Australia and the airport Manager. Please note that the airport is owned and operated by [location] Shire Council and the airport operator is a council employee.
A response was received from both CASA and Airservices.
It is important to acknowledge that the CASA response did not definitively object to the infringement with their correspondence including the following comment:
However, if Council considers as part of your own safety and risk management approach that the application is to be approved, CASA recommends that that the structure be obstacle lit by medium intensity flashing red lights at the highest point of the structure. Obstacle lights are to be arranged so as to at least indicate the points or edges of the object to ensure the object can be observed in a 360° radius as per subsection 9.4.3 of the Manual of Standards Part 139 - Aerodromes. Characteristics for medium intensity lights are stated in subsection 9.4.6. (http://www.comlaw.gov.au/Details/F2012C00280/Html/Volume_2);
The Airservices Australia response did not object to the tower.
The airport manager was more definitive in his response advising that his preference was for the application to be refused due to the intrusion.
Based on this feedback, the proponent engaged [a second company] to prepare a further report. This report stated in part that:
Since there is at least one tree with an overall height equal to or greater than 205.8 m [Australian Height Datum] AHD[1] (and other trees extending to a height of greater than 202 m AHD) within close proximity to the proposed tower, the proposed tower will not be the critical obstacle with respect to [airport]’s OLS and the application should not be refused on the basis of aviation safety concerns.
CASA and the airport manager were then provided a further opportunity to respond and essentially their advice did not change.
The planning assessment was completed and the matter reported to the [date] 2015 ordinary meeting of council. As per that assessment the recommendation from the Council planning staff was for refusal, particularly due to the objections from the airport manager.
The planning recommendation was subsequently not supported by the elected Council who resolved as follows:
That Council gives approval to [number] subject to appropriate conditions including that the proponent and the NBN be responsible for all maintenance and liabilities associated with the tower and indemnifies [location] council and the [location] airport from any liabilities concerning the tower’s intrusion above the airport’s obstacle limitation surface (OLS).
The development consent has subsequently been issued to the proponent. It is important to note that the Council resolution specifically seeks an indemnity from NBN for this intrusion and it is unclear as to whether or not that indemnity can be provided to Council’s satisfaction. Any tower will also need to comply with the CASA recommendations mentioned earlier.
[1] ATSB comment: At this location, ground level is about 150 m AHD.
CASA has reviewed the REPCON and can confirm that in September 2014, [location] Council notified CASA of the proposed NBN tower at [location] and requested advice.
CASA's assessment indicated there would be an infringement of the approach surface for runway [number] and the proposal made no provision for lighting or marking of the obstacle. The proposal was assessed as a hazardous object under Civil Aviation Safety Regulation 1998 (CASR) 139.370(1).
CASA notified the approving agency as required under the regulation, which enables a consideration of risk mitigation options. CASA recommended that the tower should be lit with a medium intensity flashing red obstacle light.
The proponent commissioned an aeronautical study which showed that the proposal was 11.4 kilometres from the runway and surrounded by trees of similar height, including some that were taller.
CASA has assessed the study and accepts the conclusion that lighting and marking of the tower in accordance with Chapter 9 of the Manual of Standards for Part 139, would be an acceptable means of risk mitigation.
As this is not a Commonwealth leased airport, the Department of Infrastructure and Regional Development does not need to be consulted during the approval process.