Two people who were flying from Cork to Roscommon were seriously injured following a crash-landing in a field in Galway last year.
A new report from the Air Accident Investigation Unit reveals that the type of fuel used on the plane during the flight was a contributory factor in the crash.
This incident took place last July when a Cessna small airplane was on its way from Cork to Tibohine airfield in Roscommon with a pilot and a single passenger on board.
During the flight, the plane encountered difficulties resulting in an engine failure and a mayday call was made to the Shannon airport air traffic control.
Just two minutes later the plane crash-landed near Kilmordaly in Galway, resulting in serious injuries to those on board and significant damage to the plane due to the hard impact with the ground.
The pilot was airlifted to the hospital for medical treatment and the passenger was taken by ambulance to the hospital.
The AIU reports found that the fuel used in the aircraft was not approved for use and the probable cause of the crash was loss of control due to stall and wing drop following a detonation induced engine failure.
The plane was airworthy and no issues were found with the pilot's licence, ratings or medical certificate.