Incident Overview
On 5 March 2018, at 06:55 UTC, the flight crew of a Boeing 737-400 received clearance for takeoff from Runway 15 at Warsaw Okęcie Airport (EPWA). After stabilizing engine parameters, the crew pressed the TOGA (Takeoff/Go-Around) button, at which point a TAKE OFF CONFIG warning illuminated. The crew promptly rejected the takeoff and vacated the runway.
Post-Event Actions
Following the rejected takeoff, the crew conducted a system check but could not identify the cause of the warning. The aircraft was parked, and maintenance personnel were called to investigate. A mechanic inspected all relevant systems and requested the crew to run through the takeoff sequence; no anomalies were found. The subsequent takeoff proceeded without any issues.
Reporting and Data Analysis
The crew submitted an Air Safety Report (ASR). A Flight Data Monitoring (FDM) specialist analyzed the recorded parameters using Aerobytes software and confirmed the data was valid. The flight data recorder (FDR) showed that the aircraft had reached a speed of 34 knots during the rejected takeoff. The TAKE OFF CONFIG warning is not recorded as a parameter on this aircraft type. The FDR taxi sequence aligned with the crew's report.
Finding and Conclusion
The Polish State Commission for Aircraft Accident Investigation (PKBWL) classified the event as a single occurrence and closed the investigation. The cause was determined to be an unjustified TAKE OFF CONFIG warning that did not recur after system reset. The aircraft remained in normal service.
Weather and Safety Recommendations
Weather conditions were not a factor. No preventive actions were taken by the operator, and the PKBWL did not issue any safety recommendations.