What aircraft was involved and where did it happen?

The accident on null involved a aircraft, at IE.

What was the probable cause of the accident?

The presence of a broken yellow line from a disused temporary taxiway, combined with poor visibility caused by wet pavement and low sun glare, led to two aircraft deviating from the correct taxiway centerline.

Taxiway Markings Issue Identified at Dublin Airport

Two separate taxiway deviations involving aircraft at Dublin Airport have prompted a safety recommendation to remove disused markings.

What happened

On the morning of 5 January 2011, an Airbus A320 was being towed northwest along Taxiway F-Outer at Dublin Airport when it stopped near Stand 87T while waiting for Air Traffic Control clearance. During this period, the crew of the A320 observed two other aircraft traveling in the opposite direction deviating from the established centerline of Taxiway F-Inner. Instead of following the continuous yellow line, these aircraft were initially following a broken yellow line located on the pavement between the F-Inner and F-Outer taxiways.

Both aircraft eventually corrected their paths as they approached the stationary A320. While no collision risk was present, the pilots of both aircraft noted that they had been taxiing along the broken line before maneuvering back to the correct centerline. The pilots also reported that identifying the proper taxiway markings was particularly difficult due to the wet pavement and the glare from a low sun.

The investigation

An investigation into the incident reviewed data from the Advanced Surface Movements Guidance and Control System (ASMGCS). This data confirmed that the two aircraft, which passed the area several minutes apart, had both drifted to the right of the Taxiway F-Inner centerline before correcting their course.

An inspector surveyed the site the following morning under similar lighting and weather conditions. The investigation established that the broken yellow line in question was a remnant of a temporary taxiway used during previous engineering works. Visual inspections confirmed that the presence of this line, combined with low sun angles and damp surfaces, contributed to the difficulty in distinguishing the active centerline from the disused marking.

Findings

The two taxiway deviations were independent events occurring several minutes apart.
The pilots of both aircraft experienced difficulty identifying the correct taxiway markings due to low sun glare and wet pavement conditions.
The broken yellow line was a leftover marking from a temporary taxiway used during construction.

Safety action

The Dublin Airport Authority (DAA) is recommended to remove the broken yellow line between Taxiway F-Inner and Taxiway F-Outer as soon as possible. Additionally, any other similar markings representing disused taxiways should be removed to prevent future confusion.