Summary
On June 17, 2015, an Embraer 175 aircraft experienced a temporary loss of communication while descending for landing. The incident resulted in no injuries among the 68 occupants.
Event Details
During the descent phase, while using the VHF1 radio, communication was lost for approximately 10 minutes. The crew attempted to restore communication using the VHF2 radio, but the connection quality was poor. Subsequently, the VHF3 radio, normally used for digital ACARS communication, was switched to voice mode, and communication with air traffic control was re-established. Later in the flight, the VHF1 and VHF2 radios returned to normal operation.
After the flight, the crew recorded the fault in the technical log and filed an ASR report. A maintenance technician checked all radios and cleared the fault as repaired. However, a check of the operator's electronic fault recording system showed that the fault had not been recorded because faults occurring at foreign ports were not being transcribed. The same fault had not occurred previously and did not recur in the following 30 days.
Findings
The investigation could not determine the root cause of the communication loss because the fault disappeared and did not recur. It was considered that the cause might have been a temporary failure of a ground communication system.
Probable Cause
The investigation could not determine the cause of the loss of communication because the fault did not recur; it may have been a temporary failure of the ground communication system.
Actions Taken
The incident was recorded in the operator's Safety Management System (SMS) database and classified according to established criteria. It was to be included in safety performance indicators monitored as per the SMS Manual. The maintenance organization was instructed to train staff in transcribing entries from the technical log—including those made by other maintenance organizations at foreign ports—into the electronic fault recording system in English. No safety recommendations were issued.