The absence of centreline lighting and the 60 m width of runway 11/29 at Darwin result in very limited visual cues for maintaining runway alignment during night landings in reduced visibility.
Response by Darwin Airport Operator
On 18 September 2017, Darwin International Airport (DIA) advised: The Department of Defence position in 2011 was as follows and DIA is not aware of any change to that:
a. Existing approach lighting at Darwin is appropriate for a Cat 1 precision approach runway.
b. Installation, upgrade and maintenance costs do not represent value for money.
c. The installation of runway centreline lighting is not imperative and will not be pursued (DIA are in agreement).
d. The option of reverting the runway lighting to 45m width would be costly and viewed as a low priority infrastructure change.
In previous correspondence Defence did indicate a concern for potential damage to tail hook equipped aircraft. Under the terms of the Joint User Agreement, Defence is responsible for airfield pavements and lighting and is considering resurfacing of Runway 11/29 in about 2022. Replacement of runway lighting may occur as part of that project. Provision of centreline lighting could be considered at that time.
On 25 January 2019, DIA advised: Darwin Airport is a Joint User aerodrome with the Department of Defence. As previously advised, and under the terms of the joint User Deed, the Department of Defence is responsible for forward planning of pavement overlays and upgrading or replacement of airfield lighting. DIA will continue to consult with Defence on whether lighting upgrades, including centreline lighting could be considered for future works. A planning meeting is proposed for March 2019.
On 8 February 2019, the Defence Flight Safety Bureau advised: The lack of centre line lighting at Darwin has been an ongoing issue for some time. Under the Joint User Deed, Defence and DIA are required to work together on any infrastructure matters. To date, Defence and DIA have been in agreement that runway centreline lighting is not supported for reasons that include upfront capital cost, ongoing maintenance issues and consideration of the potential effects of runway centreline lighting on aircraft taking the arrestor cables.
On 26 March 2019, DIA advised: Northern Territory Airports (NTAP) and Defence met on Wednesday 13th March in Canberra to discuss maintenance, projects and operational matters associated with the Joint User Area at Darwin International Airport / RAAF [Royal Australian Air Force] Darwin. A topic of tabled discussion was Airfield Ground Lighting (including a session on Runway Centreline Lighting) for RWY 11/29. Both NTAP and Defence agreed that the use of Hook Arrestor Cable System on RWY 11/29 prevented the safe introduction of CASA MOS139 compliant Runway Centreline Lighting since the risk of FOD [foreign object debris] caused via damage to Runway Centreline Lights by the Hook Arrestor Cable was of significant concern. It was however tabled that both Runway Centreline Lighting and reducing the runway width from 60m to 45m would be re-considered in future major project design briefs.
ATSB comment
The airport has undertaken safety action enhancing en route supplement guidance to flight crews, which will help flight crews conducting operations into Darwin to more effectively plan for and respond to a partial loss of visual cues there. However, this action is not a completely effective way of addressing the risk: crew preparedness can reduce the likelihood of, but not prevent, an undetected loss of adequate visual cues. The ATSB acknowledges the other safety actions and the practical limitations of installing and maintaining runway centreline lighting, and continues to encourage additional safety action. As a result, the ATSB has released the following safety recommendation.
The safety actions undertaken by Darwin International Airport adequately address the safety issue.
The Australian Transport Safety Bureau recommends that Darwin International Airport address the risk of very limited visual cues for maintaining runway alignment during night landings in reduced visibility that arise from the combination of the absence of centreline lighting and the 60-m width of runway 11/29 at Darwin.
DIA and Department of Defence (Defence) have concluded a consultation process re ATSB's Transport Safety Report. Runway centreline lighting and the 60m runway width were both key topics of discussion.
The unique "joint user" operations on runway 11/29 at Darwin International Airport including tail hook equipped military aircraft and the runway hook-arrestor system were discussed along with general civil operations in assessment of risk associated with the installation of runway centreline lighting.
The position of DIA and Defence remains aligned. Priority remains a CASA compliant aerodrome at Darwin for safe and efficient operations. DIA and Defence have agreed to the following actions to be considered and realised under the pending P0009 Defence National Airfield Works Project:
DIA notes that the runway centreline lighting identified by ATSB's letter on 9th May 2019 has been investigated and seems not to comply with the photometric standards of CASA MOS139. All were therefore deemed non-suitable. Neither DIA nor Defence intend to pursue runway centreline lighting at DIA in conjunction with runway hook-arrestor operations due to the increased risk of FOD. Such risk is considered too high.
The ATSB acknowledges the ongoing work by DIA and Defence to find an effective and practical solution, and will monitor progress and assess the safety issue on completion.
Resurfacing will now take place in the dry season of 2024 or 2025. Under consideration is the reduction of runway width from 60m to 45m, while maintaining outer 7.5m wide shoulders. New inset runway edge lighting would be installed at 45m width.
The ATSB will monitor progress and assess the safety issue on completion of safety actions.
On 5 June 2024 Darwin International Airport advised:
In June 2023 the Department of Defence commenced a full depth reconstruction of Runway 11/29, major drainage works and replacement aeronautical ground lighting.
Runway width was redeclared and marked at 45 m wide on 27 November 2023, while runway edge lights remained at 60 m width.
New runway edge lights are to be installed at 45 m width and the cutover is planned for 25–27 October 2024.
New high intensity approach lighting with sequenced flashing is to be installed with all works estimated for completion in March 2025.
The ATSB notes progress to date and will assess the safety issue on completion of safety actions.
On 29 October 2024, Darwin International Airport advised:
The ATSB notes the delay in edge lighting installation, and welcomes the addition of sequenced flashing lights to aid approach visibility prior to reaching the runway. The ATSB will continue to monitor this safety action.
On 6 March 2025, Darwin International Airport advised that the installation of 45-m runway edge lighting, high-intensity approach lighting and sequenced flashing lights had been completed.
