David Henderson was found guilty of recklessness or negligence likely to have endangered an aircraft.
The man who organised the fatal flight of footballer Emiliano Sala has been jailed for 18 months by a Cardiff court.
David Henderson was found guilty last month of acting in a reckless or negligent manner that could have endangered an aircraft.
He previously pleaded guilty to operating a commercial aircraft without permission.
But after two weeks of hearings and seven hours of deliberation, the jury of a Cardiff court found Henderson guilty of hiring a pilot he knew was not qualified.
The small private plane carrying the 28-year-old Argentinian player and pilot David Ibbotson crashed in the English Channel on 21 January 2019. The FC Nantes striker was joining Welsh side Cardiff City in a €17 million transfer.
The UK Aviation Accident Investigation Bureau (AAIB) has ruled that the pilot lost control of the aircraft -- a Piper PA-46 Malibu -- during a high-speed manoeuvre, "probably" intended to avoid bad weather.
The AAIB also suggested the pilot was "probably" poisoned by carbon monoxide from the engine exhaust system.
Sala's body was found in the plane's wreckage, more than two weeks after the accident, but the body of the 59-year-old Ibbotson has not been found.
The accident shocked the football world and prompted tributes in Cardiff, Nantes, as well as Sala's home country of Argentina.
The court found that Henderson was supposed to fly the aircraft himself but entrusted the job to Ibbotson, who did not have a pilot's licence to fly the type of aircraft and fly at night.
Prosecutors accused the suspect of acting "in his own financial interest" and knowing full well that the pilot was not qualified.
The owner of the Piper Malibu had told the court that she had explicitly asked the defendant in writing not to use David Ibbotson's services again, after several reported infractions.
Henderson's lawyers had argued that his alleged offences were "purely a matter of paperwork" and had not put the flight at risk.
Before taking the small private plane, Emiliano Sala had sent a message on WhatsApp stating that the aircraft "looks like it's going to fall apart".
"I'm scared!" the player said in a voicemail message sent to his relatives.