To reduce such a possibility, recently a new aviation system was launched called the “Automatic dependent surveillance-broadcast” or ADS-B.
ADS-B enables aircraft to determine their position via satellite navigation, then transmit that information to a base station. They can also receive information from the base station, including weather info and the location of nearby traffic. It’s a better system than secondary radar and someday will eventually replace it, but for now pilots and controllers have access to both.
There’s also another hi-tech source of information about airliners that’s a bit more obscure, because it isn’t visible to air traffic controllers. It’s called ACARS which stands for Aircraft Communications Addressing and Reporting System. It’s a way that aircraft can communicate automatically via telex-style messages with an airline’s dispatch and maintenance offices. Depending on the service, a plane’s computer can transmit anywhere from once a minute to every half-hour. In the case of the crash of Air France Flight 447 in Senegal in 2009, after the authorities realized that the plane had disappeared, they went back and retrieved its final ACARS transmissions, which revealed that the plane had experienced a cascading series of problems just before it was lost. However, after Flight 370 went missing, the airline had stated that its ACARS reported nothing unusual. Yet they don’t say how often the messages were received, or if the system was even turned on. The latest is doubtful given the fact that Malaysian authorities expand the search area without clear clues of where to look for, says aviation expert Chris Yates.
“Since the prime minister of Malaysia made his dramatic announcement on Saturday that certain aircraft functions were deliberately disabled, that in and of itself probes the fact that he announced turn back and the flight out of the Indian Ocean to somewhere. They necessarily expanded the search area, now covering something like a tenth of the globe’s surface,”Chris Yates said.
So no ACARS, no secondary radar, no radio calls and no ADS-B to help search teams find Flight MH370. Only two causes could result in an aircraft losing communications entirely – either an electronics failure or somebody turned it off. With each passing day, investigators seem to be more convinced that the latter is the key to this mystery.