Comdt Dave Brown of the Baldonnel base told a hearing into the facility that, were the incinerator to go ahead, the Air Corps would need to impose a no-fly zone around it, with other restrictions also likely, including no possible operations at the Haulbowline Naval Base in southerly wind conditions.
“The proximity of the stack of the waste-to-energy facility to the approach paths of Haulbowline Naval Base and Spike Island is a matter of concern,” Comdt Brown said. “This is due to the fact that this stack will be emitting significant amounts of exhaust gases and is seen as a potential hazard as it may render approaches by Air Corps helicopters into Haulbowline and Spike Island as unsafe.”
Comdt Brown cited a previous Air Accident Investigation Unit report which describes a helicopter flying through an invisible exhaust plume in Dublin, which resulted in engine failure and required an engine-off landing which caused “significant damage”.
Following that report the Irish Aviation Authority published a circular on the dangers of exhaust plumes in which it stated that a helicopter pilot would have to assume a danger area around a chimney of up to 1,000ft above a chimney.
Comdt Brown also referred to a US report on the same subject which recommended that pilots not fly through such plumes while accepting that sometimes they are invisible and therefore cannot be avoided.
The same report warned that hazards from plumes “taken individually or cumulatively, could possibly result in the loss of the aircraft or fatal injury to the crew”.
Comdt Brown said that, in the event of an accident at the incinerator, road access to and from Haulbowline was threatened.
“For example, if an accident at the incinerator necessitated local area evacuation, the evacuation of Haulbowline would be denied,” he said.
“This cannot be an acceptable situation for those that work at or visit Haulbowline, nor for the necessary functioning of a fully operational Naval Base therein.”
Rory Mulcahy, SC for Indaver, said it was “somewhat unfortunate that these concerns were not brought to anyone’s attention before this hearing”, but Indaver maintained exhaust plumes would not be an issue.