What happened
On March 5, 2018, at 06:55 UTC, a Boeing 737-400 operated by PLL LOT was cleared for takeoff from Runway 15 at Warsaw Okęcie Airport. After the crew stabilized engine thrust and engaged the TOGA (Takeoff/Go-Around) mode, the aircraft displayed a T/OFF CONFIG warning. In response to the alert, the crew aborted the takeoff and taxied back to the apron.
Following the incident, the crew performed a systems check but was unable to identify the source of the warning. Due to the unidentified malfunction, the decision was made to park the aircraft and request technical assistance. After a maintenance technician inspected the systems and requested a restart of the takeoff sequence, the subsequent takeoff attempt was completed without further issues.
The investigation
The PKBWL examined the flight data and maintenance actions following the event. The crew filed an Air Safety Report (ASR), and a Flight Data Monitoring (FDM) specialist conducted an analysis of the Aerobytes parameters. The investigation confirmed that the flight data recorder (FDR) accurately reflected the crew's report, including the taxiing sequence. The analysis noted that the specific T/OFF CONFIG signal is not recorded as a discrete parameter on this particular aircraft type. The investigation concluded that the event was an isolated occurrence.
Findings
- The primary cause of the incident was an unjustified technical warning regarding the takeoff configuration.
- The warning did not recur after the systems were restarted.
- Atmospheric conditions had no impact on the event.