Incident Summary
On January 4, 2022, a Boeing 787-8 aircraft, registration SP-LRA, experienced an unusual smell of burning plastic in the passenger cabin during its descent to land at Warsaw Chopin Airport (EPWA). After landing, maintenance personnel initiated the prescribed fault isolation procedure for smoke or fumes in the cabin (FIM DMC-B787-A-21-20-F5-72A-421A-A). Despite thorough inspections, no defects or anomalies in component operation were identified that could explain the burnt odor.
Investigation Findings
The aircraft remained powered on with most systems active for several hours under observation by technical staff. During this period, no recurrence of the smell or any smoke was noted. Based on information in the fault isolation procedure indicating that recirculation fans could be a source of unusual odors or smoke, the decision was made to replace the lower right recirculation fan (RECIRC FAN LWR R). Following the replacement, the aircraft was returned to service.
Cause
The cause of the incident was not determined. No irregularities were found that could have led to the smell of burning in the passenger cabin.
Preventive Actions
In response to the incident, the operator (LOTAMS) took the following preventive measures: 1. Notification of the event to maintenance area managers to inform maintenance personnel. 2. Information shared with the LOTAMS Training Department for use during periodic Human Factors training and type-specific courses. 3. Discussion of the incident at a meeting with area Safety Officers. 4. Registration of the event in the LOTAMS Event Database, to be considered when calculating Safety Performance Indicators (SPI).