Faulty plane exhaust led to fatal carbon monoxide levels, Emiliano Sala inquest hears

The Argentinian striker had just signed for Cardiff City in a £15 million transfer from Nantes. Credit: PA Images

A faulty exhaust was the most likely cause of deadly carbon monoxide levels inside the cabin of the plane carrying footballer Emiliano Sala, an inquest has heard.

The Argentinian striker died alongside pilot David Ibbotson, 59, when the aircraft crashed into the sea near Guernsey during a flight from France to Cardiff in January 2019.

He had just signed for Cardiff City in a £15 million transfer from French Ligue One side Nantes.

The inquest had previously heard how blood test results taken from the body of Sala showed he was overcome by toxic levels of carbon monoxide poisoning prior to his death.

The body of Mr Ibbotson, from Lincolnshire, has never been recovered.

On Tuesday, an inspector with the Air Accidents Investigation Branch (AAIB) said there could only be two explanations for the build-up of carbon monoxide: fire or a damaged exhaust.

A search vessel recovered Emiliano Sala's body from the plane wreckage, which was discovered on the seabed. Credit: PA Images

Brian McDermid told Dorset Coroner's Court there was no evidence of a fire in the cabin of the single-engine aircraft prior to the crash, and therefore the exhaust system was the likely cause.

The inquest heard how carbon monoxide is odourless and tasteless and piston engine exhaust fumes contain between 5% to 7% carbon monoxide, which can be fatal if exposed for more than one to three minutes.

"We first became aware of carbon monoxide being an issue when we received the toxicology report," Mr McDermid said.

"At that point, we had been looking at a loss of control in flight and flight break up."

Explaining how the carbon monoxide could have entered the cabin, Mr McDermid said the plane was fitted with an onboard heating system, which drew cold air in from outside.

The air passes through a sealed chamber and is heated by the exhaust gasses as they flow through the system.

Tributes for Sala were laid outside Cardiff City Stadium around the time of the incident. Credit: PA Images

Mr McDermid said it took a while for the investigation to make its conclusion.

"I went through the summaries of 190 accident reports, and I could not find anything there referring to problems with carbon monoxide - there was no history for it.

"Since 1984 we have not been able to identify something similar.

"When we looked at all the possibilities this one was the most probable explanation and there must have been significant disruption (to the exhaust system).

"It was on the balance of probabilities we reached the conclusion it was the exhaust muffler."

The inquest in Bournemouth also heard how light aircraft pilots are encouraged to carry carbon monoxide detectors on flights - particularly with it being odourless - but this is not mandatory.

Mr McDermid told the inquest that there was no record of pressure testing being carried out on the plane's exhaust system, although there was no legal requirement to do so.

"When the aircraft left that last maintenance check there was no evidence to suggest that the aircraft was not serviceable or fit to do that flight," he said.

"Something [happened] on the way to Nantes - that bang. We tried and talked to a lot of people. What could it possibly be and was it a release of energy that weakened something?

"I would have had an engineer look at the aircraft to find out what the bang was - things just don't happen for no reason."

The inquest, which is taking place at the Town Hall in Bournemouth, is due to last around a month.