An Indonesian family who lost three relatives when the Sriwijaya Air plunged into the Java Sea, killing all 62 people onboard in early January, is suing Boeing, alleging the Boeing 737-500 was “ defective and unreasonably dangerous.” The law firm representing the family filed the suit in Cook County, Illinois where Boeing headquarters are based. The suit alleges the aircraft was defective in more than one way, including possible faults in the autothrottle system, which controls engine power automatically and flight control system after a pilot had reported a problem on an earlier flight.

Court documents also claim the jet had possible corrosion on “the engine bleed-air fifth stage check valve” which they say caused it “to become stuck in the open position during flight, resulting in an uncontrollable compressor stall.” The black box containing the data recorder has been recovered but investigators have not located the cockpit voice recordings. A preliminary accident report is expected in early February.