Malaysia Airlines, whose MH370 airplane vanished with 239 people onboard three years ago, has become the first airline to track its fleet of planes via satellite.

The airline signed an agreement with aerospace companies Aireon, Sitaonair and FlightAware, that will enable it to monitor its aircrafts in real time, anywhere across the world.

Aireon's new satellite network is expected to be completed in 2018.

“Real-time global aircraft tracking has long been a goal of the aviation community,” Malaysia Airlines Chief Operating Officer, Izham Ismail, said in a statement.

“We are proud to be the first airline to adopt this solution."

Most flights are traceable by radar; transponders on planes automatically transmit the plane's identity via a four-digit code to air traffic controllers.

Once an aircraft is more than 240km out to sea, airliners then use equipment like high-frequency radio to keep in touch with air traffic control.

Flight MH370 which disappeared in 2014, was similarly packed with such equipment but vanished without a trace.

The plane, which left from Kuala Lumpur and was Beijing-bound, has become one of the world's greatest aviation mysteries.

According to a Bloomberg report, however, the Aireon tracking system might not have made a difference in tracking down MH370 because the plane's location transmitter was not turned on — and would not have been visible to satellites.