Rescue helicopter hit uncharted rocks
The Irish Coast Guard (IRCG) S-92A, on a night SAR mission, hit Black Rock Island, which had been omitted from its electronic chart system.
At around 2140 UTC on 13 March 2017, the Malin Head Marine Rescue Sub Centre (MRSC) scrambled the IRCG Sikorsky S-92A to pick up an injured crewman from a fishing boat positioned ~140 NM west of Eagle Island, Co Mayo.
The crew of 4 - 2 pilots, winch operator and winchman - departed Dublin Airport at ~2300 UTC and declared that they would route via Blacksod, Co Mayo, to refuel. They transited at 4,000 ft and at 0034 UTC (14 March) descended to 200 ft radio altitude at 75 kt to refuel at Blacksod, entering a direct route into the flight management system to a waypoint as an approved approach to Blacksod. Visibility was 2-3 km, with a cloudbase of 3-400 ft and wind gusting up to 35 kt.
But, as they approached the first waypoint of Black Rock, a rear crewmember, probably using electro-optics, called for a rapid turn to the right; 13 seconds later the helicopter hit the rock, causing it to break-up and killing all 4 crew.
Black Rock is located in the Atlantic and is the largest of a group of rocks ~9 NM W of Blacksod Bay. It carries a 50 ft white lighthouse which is shown to have an elevation of 282 ft on Irish Aviation Authority (IAA) charts.
Guidance for the pilots in IRCG S-92A helicopters includes input from an Enhanced Ground Proximity Warning System (EGPWS) which, amongst other functions, is intended to prevent the aircraft from running into sharply-rising terrain or man-made obstacles. It should also provide a digital terrain map that allows pilots to view a representation of terrain and obstacles ahead - provided that these are contained in the databases.
The Irish Air Accident Investigation Unit (AAIU) has conducted a safety investigation and has produced a preliminary report which notes that Black Rock simply does not appear in the database used by the EGPWS - hence the pilots were guided to fly over it, as a waypoint, at a height which inevitably led to controlled flight into terrain (CFIT).
The preliminary report includes the recommendation:
'CHC Ireland (the company that operates the helicopters for the IRCG) should review/re-evaluate all route guides in use by its SAR helicopters in Ireland, with a view to enhancing the information provided on obstacle heights and positions, terrain clearance, vertical profile, the positions of waypoints in relation to obstacles and EGPWS database terrain and obstacle limitations.'
The interim report is at the link below, which also provides the pic . .