What happened
On June 9, 2015, at 20:20 UTC, a failure occurred in the airfield lighting infrastructure at Szczecini Goleniów Airport (EPSC). The outage specifically affected the edge lighting for taxiways A and D.
The investigation
The investigation established that the failure was triggered by heavy construction equipment being used for the renovation and modernization of runway 31L/13R. Due to a prolonged period of drought, the ground in the adjacent grass sector had become highly compacted. As a result, vibrations from the heavy machinery penetrated deep into the soil within a radius of several dozen meters around the construction site.
These vibrations caused a progressive loosening of a connection between a transformer and a lamp in the primary circuit of one of the edge lights on taxiway D. This mechanical stress led to the gradual degradation of the circuit insulation, eventually resulting in a massive ground fault. This short circuit completely disabled the power supply for the lighting circuits of both taxiways A and D. The investigation noted that the fault was not detected by the duty electrical personnel or by the lighting system's built-in diagnostics.
Findings
- The primary cause was the loosening of a transformer connection caused by ground vibrations from construction machinery.
- Soil compaction due to lack of precipitation allowed vibrations to travel further and more intensely into the infrastructure.
- The failure of the built-in diagnostic system and the inability of duty personnel to detect the specific fault contributed to the continued outage.