What happened
On March 2, 2016, an Airbus A321 operating a flight from UUDD (Dakar) to EGLL (London) experienced a period of radio silence while transiting the Warsaw Flight Information Region (FIR). After being transferred from the GS sector (132.700 MHz) to the BD sector (134.225 MHz), the flight crew failed to establish communication with air traffic control services for a duration of seven minutes.
To re-establish contact, controllers were forced to attempt communication using the international aeronautical emergency frequency (121.500 MHz). Following this intervention, the crew successfully resumed radio contact with the controller.
The investigation
The PKBWL investigation focused on the breakdown in communication between the aircraft and the air traffic control services during the sector handover. The investigation confirmed that the period of unresponsiveness lasted seven minutes and that military services were notified of the incident due to the loss of contact.
Findings
- The primary cause of the incident was a crew error regarding adherence to standard radio communication procedures during the transition between sectors.