The family are suing Malaysia Airlines under the 1999 Montreal Convention, which establishes airline liability for accidents.
“The defendant is liable for such nervous shock sustained by the first, second and third plaintiffs as a result of the death of the deceased,” the writ filed in the Victorian Supreme Court states.
The document alleges the “aircraft would not have disappeared” if not for the carrier’s negligence, which it said included failing to ensure the safety of the flight, that reasonable or adequate precautions were taken, and that the flight was “monitored and tracked at all times”.
It added that the nervous shock suffered by the 49-year-old widow and sons, now aged 19 and 15, was a “direct and foreseeable consequence of the disappearance of the defendant’s aircraft”.
The writ, filed on Friday and obtained from the court by AFP on Wednesday, does not state the nationality of the plaintiffs, but the family live in the Australian state of Victoria.
The jet is thought to have crashed into the remote southern Indian Ocean but an Australian-led effort scouring the area has so far been unable to locate any wreckage.