A report into the plane crash that killed footballer Emiliano Sala has found pilot David Ibbotson was "not licensed" to fly the aircraft at the time of the accident.
The report from the Air Accident Investigation Branch (AAIB) said Ibbotson lost control of the Piper Malibu aircraft, which broke up mid-flight during a high speed manoeuvre.
Ibbotson is likely to have been affected by carbon monoxide (CO) poisoning during the flight.
The report found Ibbotson was wrongly authorised to fly aircraft at night but there was no evidence found of completing night flying training.
It was also revealed he was paid a fee for the flight despite only having a private pilot licence which did not permit him to be paid.
Leading up to the accident Ibbotson attempted a manoeuvre at an airspeed “significantly in excess of its design manoeuvring speed.” It’s thought he did so to avoid poor weather conditions which would have affected visibility.
The report said the loss of control was made more likely as Ibbotson was operating the aircraft at night in poor weather conditions despite having no training in night flying.
Sala and Ibbotson were flying from Nantes in France to Cardiff after signing for Cardiff City, when the Piper Malibu aircraft crashed into the English Channel on January 21 2019.
The Argentinian striker's body was recovered but Ibbotson has not been found.
A previous toxicology report found Sala had been exposed to harmful levels of carbon monoxide in the cockpit when the plane crashed.
The final report from the AAIB found there was no CO detector on the aircraft and that inspection of the exhaust systems could not rule out the risk of poisoning.
The AAIB investigation identified the following as causal factors that led to the plane crash:
The pilot lost control of the aircraft during a manually-flown turn, which was probably initiated to remain in or regain Visual Meteorological Conditions.
The Aircraft subsequently suffered an in-flight break-up while manoeuvring at an airspeed significantly in excess of its designs manoeuvring speed.
The pilot was probably affected by carbon monoxide (CO) poisoning.
The also identified the several contributory factors:
A loss of control was made more likely because the flight was not conducted in accordance with safety standards applicable to commercial operations. This manifested itself in the flight being operated under Visual Flight rules (VFR) at night in poor weather conditions despite the pilot having no training in night flying and a lack of recent practice instrument training.
In service inspections of exhaust systems do not eliminate the risk of CO poisoning.
There was no CO detector with an active warning in the aircraft which might have alerted the pilot to the presence of CO in time for him to take mitigating action.
Cardiff City continues to be locked in a legal dispute with Nantes over payment of the footballer's £15 million transfer fee.
The Bluebirds argue they were not liable for the full amount because Sala was not officially a player when he died.
Cardiff City recently urged French authorities to launch an official investigation into Sala's death.
Cardiff City said they welcome the findings of the AAIB report.