What happened
On 16 January 2020, an Airbus A3/21-231, registration G-WUKG, was preparing for a commercial passenger flight from London Luton Airport to Prague. Although the flight was originally scheduled to use an A320, an aircraft swap to the larger A321 was performed for operational reasons.
During the takeoff roll on Runway 26, the pilot flying applied a standard aft side stick input at rotation speed. However, the aircraft failed to pitch up. The pilot increased the side stick input to nearly maximum deflection, but the nose still did not lift. The pilot monitoring then selected TOGA thrust, which prompted the aircraft to rotate. The flight continued to Prague, where the crew eventually realized that the passenger distribution was incorrect.
The investigation
The investigation established that a technical failure prevented an automated notification from the Operational Control Centre in Budapest from reaching the ground handling and passenger services departments at Luton. While the loading department updated the aircraft registration in the software, the passenger services department continued to seat passengers based on the original A320 configuration.
Because the A320 has only three passenger zones and the A321 has four, the passengers were concentrated in the front of the aircraft, leaving the rear zone unoccupied. The resulting Load and Trim Sheet incorrectly suggested a balanced distribution. The crew initially believed the rotation issue was caused by an incorrect stabilizer setting, only realizing the weight and balance error near the top of the descent.
Findings
- The aircraft's center of gravity was outside the permitted forward limit due to the concentration of passengers in the front of the cabin.
- A technical error caused a failure in the communication chain regarding the aircraft type change.
- The passenger services department was not notified of the swap from an A320 to an A321.
- The crew did not immediately identify that the passenger distribution was the cause of the rotation difficulty.