Following a two-week search for the missing Malaysia Airlines flight MH370, the Malaysian Prime Minister, Najib Razak, regretfully confirmed the loss of the Boeing 777 after information provided by UK satellite company Inmarsat and the UK Air Accidents Investigation Branch (AAIB).
Inmarsat explained that CPDLC – Controller-Pilot Data Link Communications, the ACARS system onboard responded to text ‘handshakes’ send periodically via Inmarsat ground stations to the satellite network, then onto the aircraft. When an aircraft is within range, or over land, the ACARS messages are relayed over VHF radio.
Inmarsat and AAIB have been involved in the global operation to find the missing aircraft since 15th March and provided the data that enabled the investigators to indicate the likelihood of the plane taking the northern and southern corridors. Further calculations using the data provided have led to the conclusion that flight MH370 found its final resting place in the Indian Ocean.
CPDLC uses electronic data messages relayed to the ground via the satellite networks and carries information such as route instructions, clearances and NOTAMs. It was discovered that the onboard communications services had been manually shut down during the early stages of the flight. The datalink systems will however, continue to respond to the electronic handshakes while the flight is operational.
Until the flight recorder is recovered, we will never truly understand the nature of the disaster that has befallen the aircraft nor the plight of the passengers and crew.