What happened
On September 16, 2015, Bydloszcz Airport (EPBY) experienced two separate power supply failures that significantly impacted Air Traffic Management (ATM) services. The first outage occurred at 06:53 UTC, resulting in the loss of the operational telephone system and tower air conditioning. During this period, the ILS GS and DME systems switched to battery power and were subsequently taken out of operational service. While the backup generator was engaged, it took five minutes to restore power to the terminal, but critical systems remained offline for extended periods; the ILS and air conditioning were restored at 07:07 UTC, while the operational telephone did not function again until 07:14 UTC. During this window, EPPO APP attempted to contact the EPBY tower regarding the arrival of flight RYR66NL.
A second power failure occurred at 07:37 UTC, causing the failure of the PEGASUS system (specifically SDD 82, 83, and FDD 97), operational telephones, the PANDORA system, and air conditioning. The ILS GS and DME were again forced onto battery power and removed from service, necessitating the issuance of NOTAM 5415. The PEGASUS system was restored at 07:41 UTC, followed by the PANDORA system at 07:43 UTC. Due to the lack of air conditioning, temperatures within the tower rose above 27 degrees Celsius. The power supply was not fully stabilized until 09:57 UTC.
The investigation
The investigation, conducted by Port Lotniczy Bydgoszcz S.A., focused on the sequence of electrical failures during a planned medium-voltage shutdown intended for substation repairs. The investigation examined the performance of the backup mobile generator and the transition of critical navigation and communication systems to battery power.
Findings
- The primary cause of the incident was the automatic shutdown of the mobile generator.
- This generator was intended to provide continuous power to the terminal during a scheduled medium-voltage maintenance operation.
- The failure of the generator during the planned transition led to the subsequent loss of ATM services and navigation aids.