A search agency says the first Chinese ship to search for the Malaysian airliner that vanished almost two years ago is due to depart Australia soon for the southern Indian Ocean equipped with state-of-the-art sonar.

Australian Transport Safety Bureau said in a statement Wednesday that the ship has been testing its Synthetic Aperture Sonar off the west Australian coast in recent days and will drop off personnel at the port of Fremantle before departing Thursday for the vast search area to the southwest.

The Chinese ship will become the fourth ship scouring a 120,000-square- kilometer (46,000-square-mile) expanse where Malaysia Airlines Flight 370 is thought to have crashed in 2014.

The Boeing 777 vanished after mysteriously flying far off course during a flight from Kuala Lumpur in Malaysia to Beijing.