The final report into the crash that claimed the lives of flying instructor Niall Doherty, 31, from Roscrea, Co Tipperary, and trainee pilot Damien Deegan, 31, from Crinkle, Co Offaly, found the probable cause was power loss due to fuel starvation which resulted in the aircraft stalling and the pilot losing control.
Two other student pilots who had flown separately in the same Cessna aircraft in the hours before the crash, reported that there was 60 litres of fuel on board prior to the aircraft commencing the first of three afternoon training flights.
It was not subsequently refuelled between each of these flights which took place on Nov 11 last.
The chief flying instructor at the Ormond Flying Club in Birr, Co Offaly, where the training took place, said fuel burn was assumed to be approximately 22 litres per hour. However, by the time the third flight commenced, over two hours of flying had taken place, and because some of the fuel in an aircraft is unusable, the supply was no longer assured.
The air accident investigator said it was “therefore likely” that as the aircraft climbed, one or both fuel tank outlet ports became uncovered and air entered the fuel supply lines, “thus causing fuel starvation”.
“Further evidence for this is the lack of fuel at the accident site and the fact that the engine was stopped at impact.” The investigator was “therefore satisfied that the cause of the engine stoppage was fuel starvation due to an inadequate fuel quantity remaining in the fuel tanks”.
He found the occupants were properly licensed and the airworthiness certification of the aircraft was valid. However, he said fatigue on the part of the instructor may have been a factor.
The investigation was concerned that the level of supervision and oversight of the club’s activities was inadequate. Eight safety recommendations were made including that the Ormond Flying Club publish further guidance regarding its fuel policies in its club rules; and that it amend its on-board record of flights to include fuel uplifts and fuel on board prior to each departure.
It was also recommended that the Irish Aviation Authority, “should consider a procedural requirement that registered training facilities amend their onboard record of flight to include fuel uplift and fuel on board prior to each departure”.