David Henderson, the businessman who organised a flight that crashed, killing footballer Emiliano Sala, has been found guilty of endangering the safety of an aircraft.
Henderson, 67, was convicted by a majority verdict of 10 to two at Cardiff Crown Court.
Just moments after finding out the plane had gone down, Henderson texted a number of people telling them to stay silent - warning it would "open a can of worms".
Henderson had arranged the flight with football agent William 'Willie' McKay.
He had asked Mr Ibbotson to fly the plane as he was away on holiday in Paris with his wife.
Mr Ibbotson, who regularly flew for him, did not hold a commercial pilot's licence, a qualification to fly at night, and his rating to fly the single-engine Piper Malibu had expired.
Mr Henderson, a father-of-three and former RAF officer, admitted in court he feared an investigation into his business dealings.
He faces maximum sentences of five years imprisonment for endangering the aircraft and two years for the lesser charge of attempting to discharge a passenger without valid permission or authorisation.
Sala's family welcomed the conviction but said they still have unanswered questions about his death. An inquest is due to start in February next year.
Daniel Machover, of Hickman & Rose solicitors, said: "The actions of David Henderson are only one piece in the puzzle of how the plane David Ibbotson was illegally flying came to crash into the sea on 21 January 2019.
"We still do not know the key information about the maintenance history of the aircraft and all the factors behind the carbon monoxide poisoning revealed in August 2019 by AAIB.
"The answers to these questions can only be properly established at Emiliano's inquest."
"The Sala family fervently hope that everyone involved in the inquest will provide full disclosure of material without further delay," he added.
"Only if that happens will Emiliano's family finally know the truth about this tragedy enabling all the lessons to be learned, so that no family goes through a similar preventable death."
Henderson did not have a Foreign Carrier Permit (FCP) which was needed to fly passengers in the American plane, or an Air Operator Certificate (AOC), which he was required to obtain.
Fay Keely, who owned the plane, had told Henderson not to allow Mr Ibbotson to pilot it, after being contacted by the Civil Aviation Authority over two airspace infringements he had committed.
However, Henderson continued to allow him to fly, with prosecutor Martin Goudie QC telling the court he had created a culture of breaching air navigation rules with the pilots he hired.
He was accused of running a "cowboy outfit" and failing to keep basic information on his pilots.
But Stephen Spence QC, defending, said his client did not act recklessly and his actions were "purely a paperwork issue".
He said his client knew Mr Ibbotson, who had been flying for decades and had accumulated around 3,500 flying miles, was an experienced pilot.
He told the court the only difference between a commercial licence and the private licence held by Mr Ibbotson was whether you could carry passengers for money or not, and not about ability.
Henderson has been granted bail and will return for sentencing on 12 November.
Kate Staples, General Counsel at the UK Civil Aviation Authority, said: "Our thoughts remain with the families and friends that were affected by this accident in January 2019.
"Aviation safety relies upon the integrity of everyone involved in the industry. Unlawful and unsafe activity such as Mr Henderson's is unacceptable and the UK Civil Aviation Authority will always look to prosecute illegal activity."