LOS ANGELES — Paris Hilton’s youngest brother was charged Tuesday with interfering with a flight crew on a trip from London during which authorities say he called other passengers peasants and made children cry with his death threats and profane tirades.

Conrad Hilton, 20, wearing a dark suit and shirt buttoned to the collar, shuffled into U.S. District Court in ankle chains with his hands manacled at his waist. A judge asked if he understood his rights and the charge, which was filed Monday and could carry a prison term of up to 20 years if Hilton is convicted.

“Yes, your honor,” he repeated after each question, but he didn’t enter a plea. He was released on a $100,000 unsecured bond, ordered to appear for arraignment March 5 and told to continue mental health treatment.

Hilton’s trouble on British Airways began moments after Flight 269 left the ground July 31. It continued for almost the entire 10 1/2-hour flight, according to a 17-page affidavit by FBI agent David Gates.

Hilton ignored instructions to keep his seat belt fastened and began pacing the aisle as the aircraft ascended, the document said. He complained that another passenger was giving him the “stink eye.”

When told to return to his seat, he became unruly, and in a series of tirades, he threatened to kill several flight attendants and a co-pilot, and threatened to get them fired, the affidavit said.

“I could get you all fired in five minutes. I know your boss,” Hilton said in one of the document’s few quotes that didn’t include an expletive.