Incident Overview
On 21 October 2015, a Boeing 787-800 aircraft experienced a communication difficulty while operating in the North Atlantic Minimum Navigation Performance Specifications (NAT MNPS) airspace. The crew was unable to establish radio communication on both High Frequency (HF) radio sets. Although transmissions from the aircraft were unreadable, the ground station's Selective Calling System (SELCAL) functioned correctly. The entire flight within NAT MNPS airspace was conducted without HF communication.
Crew Actions and Communication
In accordance with applicable regulations, the crew communicated with air traffic control using the satellite communication (Satcom) system. The Automatic Dependent Surveillance (ADS) and Controller Pilot Data Link Communications (CPDLC) systems operated normally throughout the flight.
Maintenance Actions
Following consultation with the aircraft manufacturer, a decision was made to replace both HF radios and the antenna coupler.
Cause of the Incident
The incident was attributed to a malfunction of the on-board HF radios and/or the antenna coupler.
Operator's Preventive Measures
The operator recorded the event in their Safety Management System (SMS) database and classified it according to established criteria. The incident was included in the operator's Safety Performance Indicators (SPI), which are monitored as described in the Safety Management Manual. The operator's Safety Investigation Board closed the investigation after corrective actions were taken and no further reports of the malfunction appeared. Because the reported malfunctions were limited to a single aircraft and Boeing had no information about similar incidents with other operators, no fleet-wide preventive actions were taken. However, due to the recurring nature of the malfunction, it remained under monitoring within the operator's reliability program.
Safety Recommendations
No safety recommendations were issued by the investigation commission.