Conrad Hilton To Plead Guilty To Air Assault

Paris Hilton's youngest brother, Conrad, looks set to avoid jail after agreeing to plead guilty to assaulting flight attendants on a trip from London to Los Angeles.

The 20-year-old allegedly threatened to kill crew members and called fellow passengers "peasants" on the 31 July flight.

Hilton is expected to sign a guilty plea to misdemeanour assault ahead of his scheduled court appearance on Thursday, the US attorney's office in LA said.

The charge carries a maximum sentence of six months in jail, a year's probation and a $5,000 fine.

However, prosecutors said they would seek only probation under the plea agreement.

According to an FBI affidavit, Hilton's alleged erratic behaviour began soon after take-off when he ignored instructions to keep his seatbelt fastened and began walking up and down the aisle.

He continued to cause concern for almost the entire 10-hour flight, authorities said.

Hilton told the crew he was angry over a breakup with a girlfriend, and complained that a male passenger was "giving him the stink eye".

At one point, he went to a toilet and the smell of marijuana wafted out, court papers said.

When confronted by the co-pilot, Hilton apparently ran to another bathroom and smoked a cigarette.

As the flight crew confronted him again, Hilton accused them of "taking the peasants' side".

Witnesses said Hilton added that he would "[f******] own anyone on this flight, they are [f******] peasants".

Children cried as the profanity-filled tirades escalated, authorities said.

"I could get you all fired in five minutes. I know your boss," Hilton said in one of affidavit's few quotes that did not include an expletive.

He was also accused of throwing a punch inches that missed a flight attendant's head by inches.

Hilton's attorney, Robert Shapiro, said his client's behaviour may have been "the effects of a sleeping pill" or some similar circumstance.