What happened
On October 18, 2016, an EMBRAER ERJ-175 operated by PLL LOT departed from runway 15 at Warsaw Chopin Airport (EPWA) at 15:21 UTC. Shortly after takeoff, the pilot reported a technical problem involving the slats, which was identified during the retraction process. After two unsuccessful attempts to reset the system, the crew executed the slat failure procedure as outlined in the Quick Reference Handbook (QRH). Following these actions, the crew decided to return to the departure airport. During the period the aircraft was returning, a state of uncertainty was declared at the airport. The aircraft landed safely at 15:32 UTC using a flap 5 and slat 3 configuration. The state of uncertainty was lifted one minute after landing.
The investigation
The investigation examined the flight data recorder (FDR) and the aircraft's technical status. The FDR analysis confirmed that there were no flight parameter exceedances during the incident. Maintenance personnel inspected the aircraft and identified a malfunction in the slat tilt sensor. The faulty components were subsequently replaced. The operator's internal safety management review concluded that the event resulted from normal operational wear and tear and determined that the crew's decision to return to the airport was the optimal course of action.
Findings
- The primary cause of the incident was a malfunction of the slat tilt sensor.
- The crew followed established emergency procedures (QRH) correctly.
- No violations of regulations were identified regarding the flight crew or airport services.