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

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.
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.
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."
Emiliano Sala: a timeline of events
Emiliano Sala: a timeline of events
19 January 2019: Sala signs for Cardiff after several weeks of negotiations between the two clubs
21 January 2019: The Piper Malibu plane carrying Sala and pilot David Ibbotson crashed near Alderney
22 January 2019: Search for Sala and Ibbotson suspended due to poor weather.
24 January 2019: After being relaunched, the search is officially called off with the chances of survival said to be "extremely remote".
26 February 2019: A private search is launched funded by £259,000 raised in donations,
7 February 2019: The footballer’s body is recovered from the wreckage, but Ibbotson has still not been found.
November 2021: businessman David Henderson was jailed for 18 months over the plane crash. Henderson was convicted of endangering the safety of the aircraft after a trial at Cardiff Crown Court, having also pleaded guilty to another charge of trying to arrange a flight for a passenger without permission or authorisation.
A report published by the Air Accidents Investigation Branch stated that Ibbotson was not licensed to conduct commercial flights.
January 2020: Cardiff announced a trust fund had been launched for Sala following long discussions with the family.
February 2022: An inquest into Sala’s death opened at Dorset Coroner’s Court in Bournemouth.
March 2022: The inquest concluded Sala was overwhelmed by gas from a faulty exhaust before dying in the plane crash.
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.