The single-engine plane crashed during a night-time flight from Nantes to Cardiff on 21 January.
The BBC and several other national media organisations have reported that the pilot, David Ibbotson, was colour blind and his licence restricted him to flying only in daylight.
Regulatory authorities have reportedly confirmed that Mr Ibbotson, from North Lincolnshire, did not hold a ‘night rating’ on his UK private pilot’s licence.
It is understood that colour-blind pilots are banned from flying at night as they cannot distinguish between red and green lights.
The Air Accidents Investigation Branch is currently carrying out an investigation into the crash. An interim report issued in February revealed that the plane made a number of descents, ascents and turns in the minutes before it hit the water off the west coast of Alderney.
