A plane crash in Co Offaly two years ago in which two people died, including a young boy, was probably caused by the pilot losing control in a steeply banked left turn, according to an official report.
An investigation by the Department of Transport's Air Accident Investigation Unit (AAIU) into the accident which killed UK pilot Niall Bowditch (47) and his passenger, Kasper Kacprzak (7), when their plane nose-dived into a peat bog at Ballaghassan, Co Offaly, on May 13, 2018, also found the boy should not have been allowed on the flight under EU rules.
The AAIU report said the loss of control would have resulted in a rapid loss of altitude.
It found the Cessna 208B exceeded its maximum manoeuvring speed in the turn, while an attempted recovery by the pilot was likely to have added to the loss of control.
The report said the pilot may have inadvertently rolled the aircraft beyond 90 degrees after losing control during the manoeuvre, while fuel added to the left fuel tank before the flight may have exacerbated the situation.
The investigation found no evidence of any engine failure in the aircraft, while weather conditions were not a factor.
The aircraft had taken off a short time earlier from the Irish Parachute Club's airfield in Clonbullogue, Co Offaly, with a group of 16 skydivers who had jumped from the plane at an altitude of nearly 4,000m as planned.
The Cessna, which was registered in the UK, had been in regular use at the airfield over a number of weekends before the accident and was operating its fifth flight of the day when the crash happened.
The AAIU report said the pilot had notified the airfield by radio that he was returning to land at a stage before the approach leg of the flight, but no further transmissions were received.
One eyewitness described seeing the plane flying "sideways", while another observed its wing "sticking up".
A third observer said he saw the aircraft coming "straight down" nose-first, before disappearing behind a line of trees.
One of the skydivers on the plane said the pilot performed "sharp turns as opposed to smooth turns more than once".
Another pilot who had seen the Cessna flying the day before the crash said he had performed manoeuvres which he considered "aerobatic".
AAIU inspectors said they had been contacted after the crash by a number of individuals who expressed concern about the pilot's medical fitness.
The investigation established that Mr Bowditch's pilot licence had been suspended in July 2015 over concerns about his psychological welfare, but reinstated following a number of reviews which were satisfactory.
The report said the impact of the crash was such that the entire front section of the aircraft was submerged below the surface of the bog, with rescuers needing shovels to excavate soil to access the cockpit.
Both victims had suffered multiple fractures. The AAIU said the severity of the impact and the extent of the damage to the aircraft meant the accident was not survivable.
The AAIU issued a number of safety recommendations as a result of its investigation, including a requirement for the Irish Parachute Club to revise its operational manual regarding the leasing of aircraft and the use of pilots, as well as to prohibit the carriage of passengers on skydiving flights.
It also noted that EU regulations prohibited the carrying of passengers on aircraft used for specialised flights other than those required for the mission.
"A passenger should not have been carried on board the accident flight," the AAIU said.