What happened
On June 8, 2022, a Boeing 787-9, registration SP-LSG, departed from HTZA for a flight to LHBP. The aircraft was operating under MEL 32-61-01 due to a previously identified malfunction, which necessitated flying with the landing gear in the extended position.
During the flight, the crew observed that the aircraft's performance was significantly deviating from the operational plan. Specifically, the aircraft did not reach FL280 until 50 minutes after takeoff, whereas the flight plan had anticipated reaching this altitude within 16 minutes. Furthermore, the crew noted that fuel consumption was approximately 4 tons higher than predicted. At 07:25 UTC, the crew notified flight operations that the current fuel burn rate would prevent them from reaching the destination and likely preclude any subsequent departures from Africa. Consequently, in coordination with flight operations, the crew decided to perform an unplanned landing at HAAB.
The investigation
The investigation examined the operational planning and the impact of the aircraft's configuration on fuel efficiency. The PKBWL reviewed the flight logs, the maintenance release under MEL 32-61-01, and the operational flight plan used for the departure from HTZA.
Findings
- The primary cause of the incident was an error in the operational flight plan, which failed to account for the additional fuel consumption resulting from the increased drag caused by the extended landing gear.
- There were no contributing circumstances identified.