On 22 May 2009, a temporary modification was made to the runway 11/29 lighting at Darwin aerodrome, Northern Territory (NT), due to runway works being conducted on the runway 11 threshold. At 1840 Central Standard Time1, 10 minutes prior to last light, Darwin air traffic control (ATC) attempted to activate the runway lights; however, the runway 11/29 edge lights failed to turn on. Due to the lighting failure, ATC asked all aircraft intending to land at Darwin to hold. After requesting the reason for holding, the crew of a Boeing Company 717-200 aircraft, registered VH-NXM, on a scheduled passenger service with 117 people on board, advised that they had 30 minutes of holding fuel available (equivalent to 1920).
Just prior to 1910, ATC notified the crew of the 717 the lighting was still unavailable and reported asking the crew if they could divert. Initially the crew
advised ATC that they did not have diversion fuel. However, after further calculations, they determined that they had enough fuel for an immediate diversion to Tindal aerodrome, NT. The aircraft was diverted to Tindal and landed without further incident. The pilot in command (PIC) reported that it landed with 1,000 kg of fuel remaining, equating to the fixed fuel reserve.
The lighting at the aerodrome was subsequently restored and the other aircraft holding landed safely at Darwin.
The aerodrome operator advised the ATSB that, as a result of this incident, it has implemented a number of safety actions, including:
- they introduced standard operating procedures for placing night displaced thresholds
- on the recommendation of an independent consultant, they employed an electrical engineer as the engineering manager
- investigated alternative options for establishing a cross runway primary circuit
- purchased temporary portable lighting which can be pre deployed where similar works on the aeronautical ground lights are proposed.
In addition to having robust practices and procedures in place for conducting runway works, this incident highlights the importance of using clear and consistent radio phraseology to avoid confusion between ATC and crews.