The accused Mell was approached by the girl's mother so that he could give her flying lessons.

A New Jersey-based millionaire could reportedly get five-year jail time after pleading guilty to engaging in sexual acts with a 15-year-old girl. He even stooped so low that he once put his private plane in autopilot for the explicit purpose.

53-year-old Stephen Bradley Mell of Bedminster, New Jersey, pleaded guilty to federal charges of engaging in interstate travel to engage in illicit sexual conduct and receiving child pornography in December 2018 and is now due for sentencing on Tuesday.

The victim's mother had approached the accused so that he could give her flying lessons but the father-of-three, Mell, who had a brokerage firm, was accused of committing sex acts with a 15-year-old girl.

The accused began chatting up with the girl in 2017 when he allegedly "performed oral sex acts" on the girl and reportedly brought an emergency contraceptive pill. In a text message, Mell is said to have told the girl, "If you are nervous it will hurt more. When you are turned on is when it will feel ok."

Ahead of his sentencing, Mell's legal team has argued he is a 'humble man' who was on 'multiple anti-depressants' after falling into 'a spiral of depression' brought on by survivors' guilt over giving up his seat on a fatal helicopter trip with friends in 2012.

Mell also faces sentencing in July on a state charge related to sexual activity with the teen, which he pleaded guilty to earlier this month.

The millionaire started his own charity, Air LifeLine, which flew children with medical needs anywhere in the US for treatment.

(With inputs from agencies)