Tall, dark and clean-cut, Ethan Williams would have cut a dashing figure in his pilot's uniform, driving around in his $17,000 BMW four-wheel-drive.

Except the Nelson teenager is neither a pilot, rich, nor licensed to drive a car. The unemployed 18-year-old's dream run, in which he appears to have modelled a life on Leonardo DiCaprio's depiction of conman Frank Abagnale Jr in the movie Catch Me If You Can, ended after he was caught in New Plymouth in June.

His arrest at a backpackers, while wearing a pilot's uniform and using stolen credit card details to order pizza online, resulted in his appearance in the Nelson District Court yesterday.

WANTED BY CAA: Warnings were posted at various flying establishments around the country, including Nelson, advising that Williams had been trespassed from Motueka and Nelson airports because of his "unhealthy interest in aviation".

Ethan Richard James Williams, who describes himself on Facebook as a comedian, had been in custody pending yesterday's appearance, when he admitted 30 charges, including theft, burglary, wilful trespass, fraud, breaching bail, multiple computer crimes, driving while prohibited, and using a document.

Yesterday he wore a grey sweatshirt and a resigned expression while being led back into custody, after Judge Geoffrey Ellis convicted him and remanded him for sentencing on September 27.

Warnings were recently posted at various flying establishments around the country, including Nelson, advising that Williams had been trespassed from Motueka and Nelson airports because of his "unhealthy interest in aviation".

A warning posted in the June 2011 Aviation Sports Club gliding newsletter described the 190-centimetre teenager as appearing older. "A very well-versed conman for his young years. He is very convincing".

CAA spokesman Bill Sommer told the Nelson Mail the poster was distributed by CAA safety advisers, with the co-operation of airports around New Zealand.

Williams' notoriety extends to recent claims that he fell into the trap set by Facebook scammer Natalia Burgess, who created fake online identities to forge relationships with teenage boys.

He claimed that the cyber relationship included some "pretty strong sexual advances that I wasn't particularly keen on".

Aviation authorities first became concerned about Williams on June 9 last year, when he was served with a trespass notice banning him from Nelson Airport and the aerodrome reserve. Between April 20 and May 19 this year, Williams entered the area at least four times, and on one occasion asked a Sounds Air representative about doing volunteer work.

His efforts to become someone he wasn't moved up a gear in October last year, when he duped a senior staff member at a Nelson telecommunications store into selling him two hand-held radios, cases and a pager worth $2359. He also arranged to gain repeater access from the Takaka Hill repeater so the radios and pager would operate.

Williams, who gained a St John Ambulance first aid certificate at age 14, said he was part of an ambulance operation in Motueka called Life Ambulance, and claimed to have a backup contract for St John. The second time he visited the store, he used a false name to try to hire two more radios, but staff became suspicious and called the police.

In May this year, Williams attended the Nelson Pilot Training School at Nelson Airport with the aim of getting a pilot's licence. He told the school that all his expenses were being met by a sponsor – a prominent local businessman – to the value of $408.25. Williams was soon trespassed again from the airport complex.

On the night of June 12, Williams used a drill to remove a window frame and enter the pilot training school's building. He stole a chequebook, an aviation headset, two flight manuals, navigation charts, a scanner and instructors' personal belongings, including aviation sunglasses and flight-related documents.

Williams then went on a spending spree, using personalised Nelson Pilot Training cheques to take a $400 taxi ride to Picton (including a $20 tip) and a $55 ferry trip, plus taxi and accommodation costs in Wellington.

While staying at a Wellington backpackers, Williams saw and documented a German tourist's credit card details. He then used his notebook computer to go online and order aviation accessories including a $65 pilot's shirt, and various other items, using the card details.

The next day, Williams travelled to Petone and presented himself as a pilot when he went into Asset Disposal Services to buy a $17,000 BMW four-wheel-drive, using a cheque from Nelson Pilot Training. He then went to the Airways Corporation and used another pilot school cheque to buy almost $500 worth of CAA flight manuals and navigation charts.

Several days later, Williams checked himself and "four fabricated associates" into the Ariki Backpackers in New Plymouth and ordered the pizza, which was when things started to unravel. He was arrested on June 15, while wearing a pilot's uniform. The BMW was returned undamaged, as were the Airways Corporation manuals and charts.

BACK TO EARTH

Ethan Williams' trail of offending:

March 2010: Forbidden to drive until he obtained a driver's licence.

June 2010: Trespassed from Nelson Airport.

October 2010: Deceives a telecommunications store into selling him radios and a pager, and arranges access to a repeater.

March 2011:Steals a digital recorder from a Nelson store.

April-May 2011:Enters airport area at least four times. Trespassed again.

June 2011: Walks out of Nelson's Elma Turner Library with a $3239 projector; breaks into Nelson Pilot Training building and takes aviation equipment and a chequebook; takes a taxi to Picton and a ferry to Wellington, and checks into backpacker accommodation; obtains a tourist's credit card details and buys a pilot's shirt and other items online; uses a cheque from the pilot school to buy a BMW 4X4 plus CAA flight manuals and navigation charts from the Airways Corporation; drives BMW to New Plymouth, checks himself and four fabricated friends into backpacker accommodation, and orders a pizza using the stolen credit card details.

Arrested by police in New Plymouth while eating pizza and wearing his pilot's uniform.