The pilot of the plane that crashed with Cardiff City striker Emiliano Sala on board did not have a licence for commercial flights, investigators say.
The Air Accidents Investigation Branch confirmed David Ibbotson held a private pilot’s licence, which meant he could not carry passengers for reward.
Its interim report said he could only fly passengers in the European Union on a cost-sharing basis.
It has yet to establish if this was the case with Sala.
The validity of 59-year-old Mr Ibbotson’s licence at the time of the 21 January crash will form part of the AAIB’s investigations going forward.
Sala was found in the wreckage of the Piper Malibu N264DB, which was found on the seabed 13 days after it vanished over the English Channel near Guernsey.
He had completed his transfer to Premier League side Cardiff from French club Nantes just two days earlier – for a club record fee of £15m – and had returned to France to say goodbye to his former teammates.
What is cost sharing?
As flying is an expensive pastime, cost sharing allows pilots to notch up their flying hours while sharing the cost of fuel, landing fees and other expenses with passengers.
The AAIB report said the basis on which Sala was being carried on N264DB “has not yet been established but, previously, the pilot had carried passengers on the basis of ‘cost sharing'”.
Cost sharing on private flights is allowed in the UK and the report said Mr Ibbotson, of Crowle, North Lincolnshire, had operated these type of flights before.
However, the report added that because the aircraft was US-registered, it was subject to Federal Aviation Administration (FAA) regulations, which meant he could only make the flight legally if he was paying half the operating expenses.
In addition, Mr Ibbotson needed a “bona fide purpose” for making the flight – also known in aviation as “common purpose” – and must dictate when the flight should leave, the report added.
It is understood the flight’s departure was delayed to allow Sala to say goodbye to his Nantes teammates before he left.
The report said that, on the basis of a cost-sharing flight, it “must not be made for the purpose of merely transporting the passenger”.
This is one area the AAIB said needed further investigation.
What else does the report say?
The AAIB said the plane was found in three parts on the seabed after a submersible with cameras was sent underwater.
It was “extensively damaged” and the wreckage was held together by electrical and flying control cables, while the engine was disconnected from the cockpit area.
The AAIB said it had been unable to establish how much flying pilot Mr Ibbotson had done recently, as his pilot’s licence and logbook had been lost.
Investigators would normally look to establish how many hours a pilot had flown in the preceding 28 and 90 days before a crash.
Mr Ibbotson had approximately 3,700 flying hours and held a private pilot’s licence in the UK and US.
The remit of the AAIB, which is a branch of the Department for Transport, is to conduct safety investigations into the cause of aviation accidents without apportioning blame or liability.