Accidents

Loss of Irish Rescue Helicopter

At the time of writing, the investigation is continuing; possible controlled flight into terrain; possible issues with terrain / obstacle databases. Four fatalities.

On 14 March 2017, an Irish Search And Rescue (SAR) helicopter apparently suffered Controlled Flight Into Terrain (CFIT); all four crew members were killed. Note: At the time of writing the investigation is continuing. The following discussion is based on a preliminary report from the Air Accident Investigation Unit, Ireland.

The SAR helicopter was responding to a medical emergency on board a fishing vessel. It left Dublin and requested a route to Blacksod to refuel. The flight data recorded on the Health and Usage Monitoring System (HUMS) showed the helicopter was in stable level flight until the final few seconds, when it pitched up rapidly and impacted with terrain at the western end of Black Rock.

The helicopter was equipped with an Enhanced Ground Proximity Warning System (EGPWS). This is designed to decrease instances of CFIT by increasing pilot situational awareness, including the use of alerts and warnings: it is not intended to be used for aircraft navigation. The EGPWS can provide terrain alerting using look ahead algorithms, which take information from the aircraft (e.g. position., attitude, heading) and use this in conjunction with internal terrain and obstacle databases. Neither the Black Rock lighthouse nor the island’s terrain were included in the EGPWS databases; these databases had been sourced from external suppliers by the EGPWS manufacturer.

The preliminary investigation also notes that the flight crew were following an operator-specific route guide a review of such guides has been recommended. This incident potentially illustrates the importance of the fidelity / representation and completeness Data Properties, with respect to the EGPWS databases, and the accuracy Data Property, with respect to the route guides.

Links

http://www.aaiu.ie/sites/default/files/report-attachments/ REPORT%202017-006%20PRELIMINARY.pdf
(accessed 29 November 2017).