A Hilo man charged with sexually assaulting a woman aboard a Japan Airlines flight will undergo a mental health evaluation.

Michael Tanouye was ordered to remain held without bail at a detention hearing Tuesday. U.S. Magistrate Judge Kevin Chang also granted his defense attorney’s request for a mental competency evaluation of the 29-year-old.

Tanouye was arrested Oct. 11 after the flight had to return to Honolulu because of the assault in the airplane’s bathroom.

The FBI says the flight was en route to Kansai International Airport when Tanouye forced his way into a bathroom and sexually assaulted a woman. Flight attendants and passengers told the FBI that a passenger was injured while struggling with Tanouye.

At a hearing last week, a federal prosecutor alluded to additional charges.