The Argentina-born striker died from head and chest injuries but was deeply unconscious, having been poisoned by fumes from the plane’s faulty exhaust system.
The jury at Bournemouth Town Hall found that Sala was a passenger on a private plane, being flown by a pilot who did not have the correct authority to fly at night, which broke up when it crashed into the sea.
The 28-year-old player was on board the Piper Malibu flying from Nantes in France to Wales on the evening of January 21 2019 when it crashed in the English Channel close to Guernsey, also killing pilot David Ibbotson, 59, whose body has never been found.
Sala was joining then Premier League club Cardiff City in a £15 million transfer from French Ligue 1 side Nantes, which involved football agent Willie McKay.
Pathologist Dr Basil Purdue said Sala had been overcome by “severe poisoning” and would have been “deeply unconscious” prior to the single-engine plane crashing.
Dr Purdue said Sala was still alive at the point of impact and died from severe head and chest injuries.
An engineering expert said the most likely cause for the build-up of carbon monoxide inside the cabin was from the plane’s faulty exhaust system.
Pilot and businessman David Henderson, 67, managed the aircraft on behalf of its owner and arranged flights, pilots and maintenance, despite not being the legally registered operator.
A long-time client was McKay, who was helping his son Mark’s firm represent Nantes in the transfer.
McKay, who was barred at the time from acting as an agent in the transfer in his own right because he was an undischarged bankrupt, arranged the flights to and from Nantes after Sala had completed a medical in Cardiff.
He said he only wanted to help Sala get home, and claimed Cardiff City had “abandoned” him.
McKay denied knowingly arranging illegal “grey” flights – private charters carrying paying passengers – as Henderson did not have an air operator’s certificate (AOC) that would have allowed him to fly paying passengers.
As well as not having an AOC, the court heard that Henderson kept no records or invoices for his business, or the qualifications of the pilots who flew for him.
Ibbotson had reported to Henderson that he heard a loud bang on the outward flight from Cardiff to Nantes – but an engineer was never asked to investigate when the plane landed in France.
He had been banned from flying the Piper Malibu by its owner following two airspace infringements months earlier, but Henderson allowed him to continue.
Ibbotson held a private pilot’s licence, which did not permit him to fly passengers commercially, and was not allowed to fly at night either.
Last year Henderson was jailed for 18 months after being convicted of endangering the safety of an aircraft for using Ibbotson’s services when he knew he did not have the relevant licences.
He admitted a further offence of trying to arrange a flight for a passenger without permission or authorisation.