Emiliano Sala's pilot David Ibbotson was 'not qualified to fly at night'
The missing pilot did not hold a "night rating" on his pilot's licence.
David Ibbotson, the pilot of the plane carrying footballer Emiliano Sala which crashed over the English Channel on January 21, was not qualified to fly at night, according to a BBC report.
Ibbotson, who remains missing since the crash, was believed to have been colour blind, a condition which would have prevented him from obtaining his "night rating" on his pilot's licence.
It is believed that the missing pilot was killed in the crash that took the life of 28-year-old Sala, who was returning to new club Cardiff City after a short farewell trip to see his former teammates at Ligue 1 club Nantes.
Both clubs are now in the middle of a dispute over who was Sala's employer at the time of his death.
Sala was found weeks after the crash and laid to rest in his hometown of Pregreso, Argentina on February 16.
There have been a number of questions over the exact cause of the crash, as well as the safety of the plane in general, and an Air Accidents Investigation Branch (AAIB) investigation remains ongoing, with licensing believed to be one of their focuses.
"Colour-blindness stops a pilot from obtaining a night rating straight away, because being able to differentiate between green and red lights is key to flying in the dark," an aviation source told the BBC.
"Anything that's on the UK licence applies to the US licence as well, so he couldn't do anything more than the UK licence allows.
"Flying outside the restrictions of your licence is illegal and that's likely to affect the insurance cover for the flight."
The UK Civil Aviation Authority (CAA) has said it will not comment until the AIIB's investigation is complete.