Woman who was sexually assaulted on plane says flight attendants did nothing to help her.

A US woman has filed a civil lawsuit against Delta Airlines, claiming flight attendants failed to protect her when she was sexually assaulted on a flight last July.

According to court documents, the woman was travelling from South Carolina to Detroit, when a man sat down beside her and sexually assaulted her.

CBS Detroit reports that the first class passenger, Christopher Finkley, 41, was convicted of simple assault and indecent exposure.

“And this gentleman, if I want to call him that, was fondling himself in first-class – he was noticed about 40 minutes into the two-hour flight by a flight attendant – the flight attendant apparently called down to Detroit to make sure that police would be there to arrest this man,” the woman’s attorney Jordan Acker told the station.

However, according to a sentencing memorandum, Finkley then moved towards the back of the plane to use the toilet in coach. On the way back to first class, he sat down in the empty aisle seat next to the woman, and reached his hands under her shorts.

“Shortly after the defendant sat down, he placed his hand on the victim’s upper thigh and began to rub her bare skin,” the court document reads. “While he was doing this, the defendant told her that he ‘liked white women’ and asked ‘where’s your man?’ The victims told him to ‘please stop’ and stated ‘my kids are behind me.’”

Despite the woman’s pleas for him to stop, Finkley continued to touch her thigh, claiming her was merely massaging her leg, he then put his hand underneath the woman’s shorts, before returning to his own seat.

“After his return, he resumed rubbing his penis, this time observed by a second flight attendant,” the sentencing memorandum reads. “Upon landing, [the woman] immediately texted her daughter and told her to stay in her seat because she was scared.”

Acker believes the cabin crew could have done more to protect the woman.

"What they should've done, after they found out he's masturbating and exposing himself in first class and the stewardess went to the cabin and told the pilot, who radioed ahead to call the police. They should've taken the flight attendants and monitored that man and not allowed that predator to run through the cabin," attorney Jerry Acker told WJBK.

Finkley later admitted he liked to sit with his hands in his pants and massage his penis, what he called “his happy place".

“He stated that he did not mean for the flight attendants to see his penis but that it is possible that they did,” the document reads. “Defendant then admitted to touching [the woman] on the outside of her knee and making a ‘caressing motion.’”

He pleaded guilty to simple assault and indecent exposure in November, and as WJBK reports, was sentenced to seven days in jail and one year of probation.

Delta Airlines has not released a statement about the lawsuit.