What happened
In the early hours of 19 September 2006, a BAe Systems ATP, registration SE-LPT, was performing a scheduled freight flight from Stockholm/Arlanda to Umeå airport. During the approach to runway 14, the aircraft encountered dense fog with visibility significantly reduced.
As the aircraft touched down, the crew experienced a sudden veer toward the left side of the runway. Despite the pilot's attempts to correct the heading with right rudder, the aircraft drifted far enough to the left that the main landing gear moved beyond the runway edge. During this excursion, the aircraft struck a runway edge light, shattering it and scattering glass shards across the pavement. The crew did not immediately realize the impact had occurred; the damage was only discovered during a subsequent technical inspection at Luleå airport, where technicians found unusual cuts and notches on a tire.
The investigation
The Swedish Accident Investigation Authority (SHK) examined the flight data, cockpit voice recordings, and runway inspection procedures. The investigation revealed that the aircraft's rudder trim had not been properly adjusted to achieve neutral forces for landing. Furthermore, investigators reviewed the morning's runway inspection, which had been conducted at 05:20 in darkness and heavy fog. While the inspection vehicle had traversed the runway, the inspection was performed with the runway edge lights switched off, which hindered the detection of the damaged fixture and the resulting glass debris.
Findings
- The aircraft was not trimmed correctly for the landing phase, which contributed to the lateral drift.
- The pilots had relatively limited experience on this specific aircraft type.
- The lack of runway centerline lighting made it difficult for the crew to realize the aircraft had drifted from the center.
- Poor monitoring of the aircraft heading during the landing phase was the primary cause of the excursion.
- The runway inspection failed to identify the damaged light or the glass shards because the edge lights were not illuminated during the inspection in low-visibility conditions.