‘Carburetor icing’ may have caused plane crash, finds inquiry

A PLANE crash at Raharney in Co Westmeath may have been caused by a loss of engine power resulting from “carburetor icing”, an inquiry has found.

Instructor Joseph McCabe, 38, from Lucan and student instructor Kevin Ryan, 38, from Clontarf, both experienced pilots, died when the plane crashed into a field just before 9am on May 29, 2006.

A report published yesterday by the Air Accident Investigations Unit (AAIU) found that the plane suffered a loss of flying speed at low altitude, stalled and spiralled to the ground. The flight left Weston Aerodrome in Co Dublin at 8.20am.

The investigation was unable to determine which man was in control at the time of the disaster.

It did find, however, that “carburetor icing”, which can occur in humid conditions and lead to a loss of engine power may have been a factor in the crash.

Evidence of the aircraft spinning and stalling just before it hit the ground was given by a number of eyewitnesses who were in the area at the time.

Two builders who were working on a house nearby drove to the crash scene and found the two dead pilots inside the plane.

The student instructor in the Cessna 150M — described as a “docile aircraft” — was on a pre-test exercise in preparation for his instructor rating examination, which he had already failed once.

He had been deemed ready by the Irish Aviation Authority for another exam in February of 2006 but this didn’t take place and there was an interlude of three months before he flew again. “It is noted by the investigation that the student instructor had only flown 3.73 hours in 28 days prior to the accident flight.”

However, the investigators said that responsibility for the safe flight of the plane lay with the qualified instructor and noted that both pilots were “appropriately qualified” to conduct the flight.

The investigation found that the student instructor “probably” entered an intentional spin manoeuvre at a little more than 4,000 feet altitude, in practice for his instructor rating examination.

Both pilots were sufficiently experienced and qualified to induce a spin and recover from a spin.

The impact with the ground caused some damage to the aircraft but, according to the AAIU report, the destruction was “limited”, there was pre-impact damage and minimal penetration of the ground.

Postmortem tests found that the men died as a result of shock and haemorrhage due to multiple injuries associated with severe brain damage. Alcohol and toxicology tests were negative.

Assessments of the plane during the investigation found that it was “fully airworthy” prior to the crash.

However, the lack of onboard recording equipment — while not required under law for this type of plane — “hampered the progress of the investigation”, said the report.