A California man is facing up to 20 years in prison after he allegedly assaulted a female flight attendant aboard an American Airlines flight last week.

The U.S. Attorney’s Office announced Monday that Brian Hsu, 20, has been charged with interference with a flight crew and assault within the special aircraft jurisdiction of the United States. The incident occurred on Oct. 27 aboard American Airlines Flight 976, which was headed from New York’s JFK airport to Orange County, California, but was forced to divert to Denver, Colorado.