Salt Lake County Sheriff’s Office, File, Associated Press
This image provided by the Salt Lake County Sheriff’s Office shows Hans Loudermilk. Loudermilk, a California man accused of groping and sexually propositioning a teenage girl on a flight from Los Angeles to Salt Lake City has pleaded guilty to a reduced charge. At a hearing Friday, Dec. 19, 2014, Loudermilk of Oceanside, Calif., acknowledged touching the 15-year-old's chin and rubbing her leg in March.

SALT LAKE CITY — A California man accused of groping and sexually propositioning a teenage girl on a flight from Los Angeles to Salt Lake City pleaded guilty to a reduced charge Friday

Hans Loudermilk, 66, of Oceanside, California acknowledged touching the 15-year-old's chin and rubbing her leg on the March flight. Loudermilk was sitting next the girl when he told her he could teach her things sexually that boys her age could not and said she was old enough to marry him in Utah, according to charging documents.

The girl reported the incident to security shortly after the plane landed. When Loudermilk saw her talking to officers, he entered an airport gift shop, removed his button-up shirt and replaced it with a jacket, possibly to duck police, prosecutors said.

He pleaded guilty to misdemeanor assault, or offensive touching, in an agreement with prosecutors. Prosecutors dropped two felony counts of sexual abuse on an aircraft.

Defense lawyer Robert Steele says Loudermilk didn't realize he was in the beginning stages of bipolar disorder at the time and wasn't in full control of his actions.

"That led to overly gregarious and inappropriate behavior," Steele said. Loudermilk has since started treatment for the disorder.

The California man appeared in court Friday in a tan jacket, jeans and sneakers, responding affirmatively to questions from Magistrate Judge Brooke Wells about the plea agreement.

Loudermilk faces up to a year in prison at a sentencing hearing scheduled for March 4.