A preliminary report into the accident in which 69-year-old Bryan Keane and his 58-year-old friend Paul Smith died on May 24, draws attention to a number of possible negative influences on the day, but draws no definitive conclusion.
The men, who departed Ballyboy Airfield, Co Meath, in a Cessna aircraft at approximately 9am for the purpose of attending a fly-in at a private airfield near Taghmon, Co Wexford, never reached their destination, instead crashing into the Blackstairs Mountains in Co Carlow shortly before 2.40pm.
Mr Keane, a father-of-five, and Mr Smith, a father-of-three, were both experienced pilots. Both died on impact and the aircraft was destroyed with wreckage strewn over steep slopes.
A witness who spoke to air accident investigators said he saw the dogs being placed in their customary position behind the rear cabin seats as the men prepared to depart Ballyboy.
The Cessna was equipped to a high specification.
Investigators said while there were “no general problems with cloud, visibility or weather”, the atmosphere at a certain level was “absolutely unstable”.
“This would have led to a risk of poor visibility and cloud conditions above 1,000ft due to condensation”, the report read.
There was also a SIGMET in operation, which is a weather advisory containing Significant Meteorological Information, concerning the safety of aircraft. In this case, the SIGMET indicated mountain wave activity. Mountain waves are standing atmospheric waves which form above or on the lee of mountain barriers. They are often associated with turbulence. In the presence of these waves, aircraft can experience sudden drops in altitude.
Other pilots attending the fly-in described the weather conditions in the vicinity of Blackstairs Mountain about the time of the accident, as “mist” and “drizzle” with a cloud ceiling between 800 and 1,000ft above mean sea level (AMSL).
A final report will be issued in due course.