What happened
Flight 428 was cleared to land on runway 16L at an airport where construction had closed the adjacent runway 16R. Information regarding this closure was disseminated via a Notice to Airmen (NOTAM) and announced in the Automatic Terminal Information Service (ATIS) as information Oscar. The flight crew confirmed they had received and acknowledged this briefing.
Despite being cleared for the open runway, the aircraft touched down on the closed runway 16R. The captain later explained that he mistakenly believed the left runway was the one under construction. He noted that commercial airliners typically utilized the western runway, which was 16R, rather than 16L. At the time of landing, everything appeared normal to the crew.
The investigation
An examination of the airport's lighting systems revealed a critical visual discrepancy. When Flight 428 was on final approach, the runway and approach lights for runway 16R were set to Step 3 because a separate runway inspection was underway. However, the Visual Approach Slope Indicator (VASI) and approach lights for 16R were turned off.
Conversely, the runway and approach lights for the intended destination, runway 16L, were only on Step 1. This difference in lighting intensity created a situation where the closed runway appeared more active or prominent than the open one, despite the crew having been briefed otherwise.