The pilot and plane involved in the crash that killed Emiliano Sala were unlicensed for the flight, investigators said.
David Ibbotson, 59, from Crowle, Lincolnshire, held a private pilot’s licence that did not allow him to conduct flights for reward.
But during its 14-month inquiry into the crash that killed Argentinian footballer Sala, the Air Accidents Investigation Branch (AAIB) found he “had been paid a fee for flights on numerous occasions”.
It also obtained “significant evidence” he was expecting to be paid for the accident flight, although it did not disclose how much he was due to earn.
Despite the plane taking off at 7.15pm on January 21 2019, Mr Ibbotson was not authorised to fly at night.
He also lacked recent experience in controlling a plane using only cockpit instruments, which can be required in poor weather such as those he encountered during the fatal flight.
The AAIB’s final report stated: “Payment brings with it some pressures for a flight to be completed so that the fee will be paid and, perhaps, to realise the opportunity to secure work in the future.”
Under the regulations which the aircraft was operated and maintained, it was only permitted to be used for private flights.
No permission had been sought or granted to allow it to be used on a commercial basis.
Unlicensed charter flights enable people to arrange cheaper air travel compared with legitimate operations.
The AAIB said these so-called grey charters are “often associated with sporting events” by using small aircraft to transport passengers.
But it added “it is difficult to gauge the level of activity accurately”.
Andrew Blackie, safety investigation expert at Abris Consulting and a former air accident investigator, told the PA news agency: “The problem with illegal charters is the same as with illegal taxis.
“There is no safety assurance, you may not be insured, you may have, as appears to be the case here, a pilot who is simply not competent for the conditions.
“Football and other sports need to be continually asking why Sala was in that aeroplane in the first place.”
Former football agent Willie McKay said he paid for the fatal flight but did not choose the pilot or the plane.
He was helping his son Mark, who was acting for Nantes, to complete Sala’s transfer to Cardiff City.
The AAIB revealed Sala was not involved in booking the flight and said passengers “are not expected to know about or understand the regulatory aspects of aviation”.