Incident Overview
After a normal landing on runway 30 at night—a runway the flightcrew had not previously landed on—the flightcrew taxied the airplane to the end of the runway, intending to depart the runway at the last taxiway. The flightcrew passed the taxiway exit, overran the departure threshold of runway 30, and struck two lights associated with the approach lighting system for runway 12, breaking the lights off at their bases. The airplane was not damaged, and, after being towed from the overrun area, taxied to the gate under its own power.
Flightcrew Actions
The flightcrew stated to investigators that they observed the runway centerline lights initially alternated red and white and then became all red as they taxied toward the runway threshold. They were looking for a right turn to vacate the runway but did not see any green lead-off lights leading to the taxiway. They observed a line of red lights about 50 meters (about 160 feet) in front of the airplane, which they thought were part of the stop bar indicating the runway threshold. The first officer started to turn off the runway using the blue taxiway edge lights as a guide, but immediately stopped the airplane when both he and the captain realized the light pattern was not as expected.
Runway Lighting and Markings
The lighting, signage, and airfield markings of runway 30 were operational and in accordance with Federal Aviation Administration (FAA) specifications. The runway 30 centerline lights changed from all white to alternating red and white lights beginning 3,000 feet from the runway threshold and became all red lights beginning 1,000 feet from the threshold. Runway edge lights changed from white to amber at 2,000 feet from the threshold and remained amber until the end of the runway. On the left side, "distance remaining" signs were installed at 4,000 feet, 2,000 feet, and 1,000 feet before the threshold. Approximately 500 feet before the threshold, on the right side, a taxiway sign reading "Q" with an arrow pointing right was installed. About 75 feet before the threshold, centerline lights of Taxiway Q began at the runway edge and extended perpendicular to and away from the runway. Additionally, twelve parallel white bars were painted across the width of the runway to mark the threshold, and yellow chevrons were painted on the blast pad beyond the runway threshold to indicate unusable pavement.
Investigation Findings
The investigation revealed that the red lights the flightcrew observed were obstruction lights mounted on top of an Instrument Landing System localizer antenna, approximately 500 feet beyond the runway threshold. The actual runway threshold was marked with eight red lights, consisting of four lights extending out from each side of the runway edge. The flightcrew did not correctly utilize or interpret the lighting, signage, and airfield markings to determine their exact location during taxi. FAA advisory material for new runway threshold lighting installations recommends that threshold lights extend from the runway edge inboard toward the center of the runway, not outboard like those on the incident runway; however, existing installations, such as those on the incident runway, were permitted by the FAA. The taxiway at the end of the runway did not have taxiway lead-off lights extending to the center of the runway, but the taxiway did have centerline lights beginning at the runway edge, per FAA requirements. Although the flightcrew said they were confused by the location of the runway threshold lights, they had numerous other indications available to identify their position on the runway, all of which were in compliance with FAA guidance. Each of these indications would have been visible from the cockpit and are intended to help the flightcrew navigate without incident. However, the flightcrew did not heed the numerous lighting, signage, and airfield markings for runway 30, and instead focused on lights located well beyond the runway threshold to the exclusion of all other indications.