What happened
On 22 October 2005, an Airbus A319-131, registration G-EUOB, was operating a scheduled passenger flight from London Heathrow to Budapest. While climbing through FL200 in clear weather, the crew experienced an audible 'clunk' followed by a sudden loss of electrical power across several flight deck systems. The failure resulted in the flight deck becoming dark, with the loss of the Captain’s and First Officer’s Primary Flight Displays, Navigation Displays, and the Upper ECAM1 display. Additionally, the autopilot, autothrust, and intercom systems failed, and most flight deck lighting—including overhead and pedestal panels—was lost.
Due to the loss of radio power, the commander's initial 'MAYDAY' call was not received by Air Traffic Control. The pilot flying transitioned to manual control, maintaining the aircraft's attitude by referencing the external night horizon and available standby instruments. After approximately two minutes, the crew utilized the 'AC ESS FEED' push button switch as per ECAM procedures, which partially restored some systems. The aircraft was placed in a holding pattern near Clacton for approximately 40 minutes to allow the crew to review the aircraft's status. The flight eventually continued to Budapest, where the First Officer landed the aircraft. During the landing roll, the crew noted an amber caution regarding the No 1 thrust reverser.
The investigation
The AAIB investigation was initiated following a report through the UK Mandatory Occurrence Reporting Scheme. The aircraft was removed from service for technical examination. Maintenance engineers performed integrity checks on the electrical power system and inspected the Integrated Drive Generator feeder connectors located in the engine pylons; these tests found no anomalies. To further the investigation, several components were removed for analysis, including the No 1 Generator Control Unit, all three Display Management Computers, the No 2 System Data Acquisition Concentrator unit, and the No 2 Flight Warning Computer.
Findings
- The primary flight instruments and most flight deck lighting were lost following an electrical event.
- The crew successfully restored most systems using ECAM procedures.
- The loss of primary flight displays and flight deck lighting was the central issue during the flight.
- Following the incident, the affected systems were successfully reset by maintenance personnel, and the aircraft returned to service without further reported electrical failures.