HAGATNA, Guam >> A U.S. appeals court struck down the three-year prison sentence of a rowdy Korean Air passenger convicted of interfering with flight attendants last year on a flight to Guam.

The judge who issued the sentence against dentist Kwon Woo Sung failed to use federal guidelines as a starting point for determining his prison term, the 9th U.S. Circuit Court of Appeals said Monday. A three-judge panel of the court sent the case back to Chief Judge Frances Tydingco-Gatewood in Guam for resentencing.

Kwon pleaded guilty to one count of interference with flight attendants after officials said he drank several beers and became combative during the April 2016 flight.

The dentist was accused of fighting with passengers and was subdued and tied down until the jet arrived in Guam, where he was heading on vacation.

Kwon appealed the sentence that included credit for time served under house arrest, the Pacific Daily News reported.

Federal sentencing guidelines are intended to alleviate disparities in prison terms between defendants for similar crimes. Though they are advisory, they should form the initial benchmark for any sentencing determination, the 9th Circuit said. The guidelines called for a sentence of up to six months for Kwon, according to the 9th Circuit.

Tydingco-Gatewood instead said she was throwing out the sentencing guidelines, and her initial thought was to sentence Kwon to 10 years in prison, the 9th Circuit said.