What happened
On November 17, 2014, while operating a Boeing 787-800 at cruise altitude en route to waypoint GUNPA, the flight crew received an instruction from Air Traffic Control (ATC) to divert the flight path to waypoint TUKMI. The crew was unable to execute this instruction immediately because the new waypoint was not present in the aircraft's Flight Management Computer (FMC) navigation database. Consequently, the crew had to manually input the geographic coordinates for the waypoint. Due to the resulting delay and the discrepancy in the navigation data, the supervising ATC controller required the crew to file an incident report.
The investigation
The investigation examined the discrepancy between the flight plan and the FMC data, as well as the status of the aircraft's navigation database. It was established that the aircraft had been released for flight under a Minimum Equipment List (MEL) entry because the latest navigation database update was too large to be uploaded into the FMC. The investigation also reviewed the crew's duty schedules to determine if fatigue played a role in the error.
Findings
- The primary cause of the incident was an operational error by the crew, specifically a failure to properly cross-check the flight route programmed into the FMC against the route specified in the operational flight plan.
- The crew was aware that the aircraft was operating with an outdated navigation database, yet they failed to detect the mismatch between the programmed route and the official flight plan.
- The necessity of operating under an MEL arose because the manufacturer-provided navigation database update exceeded the storage capacity of the FMC.
- An analysis of the crew's duty patterns showed no evidence of fatigue that could have contributed to the incident.
- The operator's operational services had requested permission from the Civil Aviation Authority (ULC) to utilize printed documentation for navigation during the two-month period when the database was outdated.
- The navigation database was successfully updated before the expiration of the MEL authorization.
Safety action
- The findings from this incident investigation will be utilized as instructional material during periodic pilot training sessions.