What happened
During a recent taxi sequence, the flight crew operated an aircraft without activating the necessary airport lighting. The crew proceeded to the takeoff run without realizing that the runway lights remained extinguished. This oversight occurred during a short taxi period characterized by a high workload, which limited the crew's ability to monitor environmental lighting changes.
The investigation
The investigation focused on why the lack of runway illumination went unnoticed. It was determined that the brightness from the aircraft's own taxi and landing lights obscured the view of the runway environment. Specifically, a rise on the taxiway restricted the crew's visibility to only a few lights ahead, all of which were being washed out by the aircraft's own illumination.
Furthermore, the crew did not have an expectation that the lighting might be inactive because the visual cues available were insufficient to signal a problem. Auditory warnings, such as the 10-minute warning for the Pilot Alert Light (PAL) extinguishing, were inaudible without the use of headphones. Additionally, the crew did not notice the windsock flashing light warning, as they were focused on obtaining wind data via the electronic flight bag and the Automated Weather Information Service (AWIS).
Findings
- The lack of crew expectation regarding inactive lighting contributed to the oversight.
- The illumination from the aircraft's taxi and landing lights made it difficult to identify that the PAL was not active.
- Company standard operating procedures did not assign a specific role or task to ensure runway lights were selected prior to taxi, leaving no procedural prompt for the crew.
- High workload during a short taxi period reduced the opportunity for detection.