What happened
On January 16, 2020, at 16:26 UTC, a Bombardier CRJ 900LR, registration ES-ACL, was undergoing pre-flight preparations at Warsaw Chopin Airport (EPWA). Following the engine start sequence, the flight crew notified Air Traffic Control (TWR) of smoke appearing within the passenger cabin. The odor suggested an electrical fire within the aircraft's wiring.
In response to the report, the airport duty manager dispatched the Airport Fire Service to the aircraft's location. To mitigate the smoke levels, the cabin crew chief decided to open the L1 door to ventilate the cabin. While the intensity of the smoke visibly decreased following this action, the captain determined that the safety of the occupants required an exit from the aircraft. Because no active flames or specific source of the smoke could be identified, the captain and the cabin crew chief opted to follow standard disembarkation procedures rather than initiating a full emergency evacuation.
The investigation
The PKBWL examined the sequence of events and the technical state of the aircraft's electrical systems to identify the origin of the smoke. The investigation focused on the electrical components within the passenger cabin area to determine why smoke had entered the pressurized environment during pre-flight operations.
Findings
The investigation established that the smoke was caused by a damaged relay located within the electrical installation of the passenger cabin's ceiling lighting.
Safety action
The investigating entity has implemented the following preventive measures:
- Introduction of a new rapid disembarkation procedure in alignment with Regional Jet CRJ 700/900 OM-B 11.4.
- A revision of existing flight operations procedures and algorithms regarding fire and smoke incidents to provide more detailed operational guidance.