The report into the Rescue 116 crash, which claimed the lives of its four crew, is exceptionally detailed and thorough for the results of a preliminary investigation, pilots have said.
The report identifies a lack of topographical data about Blackrock Island on R116’s enhanced ground proximity warning system (EGPWS) as a factor in the disaster that unfolded.
The system alerts pilots, repeatedly and with greater stridency if they fail to react to the initial warning, if the ground on their flight path ahead is higher than the altitude at which they are flying. However, it is not a navigational tool.
Once initial reports had ruled out mechanical failure, it seemed apparent that the disaster was a so-called Cfit crash – a “controlled flight into terrain” impact.
Cfit is the acronym used to describe the phenomenon of an airworthy aircraft being flown, unintentionally, into an object that destroys it – the ground, a mountain or water.
“People are understandably blaming it on the EGPWS manufacturer,” said one pilot. But that’s not accurate. EGPWS is a last-resort crash prevention tool and is not used for routine navigation.
“It is tragic that it wasn’t in the [R116’s] database but the crew obviously lost situation awareness as to where they were,” said the pilot, who, like others, spoke on condition of anonymity.
Each country that buys the Honeywell-made EGPWS system provides the required local topographical data: "The main island of Ireland is there but, for whatever reason, not all of the offshore islands are," said another pilot.
Highest peak
The aeronautical maps that crews consult show islands and the height of the highest peak but not the contours – the lines on maps showing points of equal elevation, whose closeness indicates steepness.
“They don’t have the topographical data [for all islands], and the colouring of the contours, just the figure for the highest elevation,” said the pilot, noting carefully that the precise cause of the crash may not be noted for months.
“Every now and again, something pops up – like a series of holes in a Swiss cheese suddenly aligning – that we didn’t expect. There can be failings, absences, that didn’t cause a problem before but has now,” he said.
In time, it may be necessary to upgrade “refresher training” to ensure crews are familiar with operating procedures, or do not become over-confident on regularly taken routes and are kept familiar with rarely used routes.
“They were following the correct approach,” said one pilot of the route Rescue 116 was taking coming into Blacksod, their refuelling stop, but was there a problem using an east coast-based crew for a west coast operation, he said.
“You can see in the conversation on the way they are talking about not having been in the area for a while,” said this pilot.
“That obviously bothered her [Capt Dara Fitzpatrick] and him [co-pilot Mark Duffy].
"They were aware of not being comfortable with that," said the source. However, R116, travelling at 130km an hour, was at the correct speed for a 200ft-high approach towards Blacksod lighthouse on Belmullet.
