The ATSB is investigating an occurrence involving Sikorsky S-92A, registration VH-IPE, 110 km north of Learmonth Airport, Western Australia, on 1 February 2025.
During approach to an offshore vessel at night, the crew inadvertently disconnected the radar altimeter hold which would have stabilised the aircraft at a circuit height of 660 ft. The aircraft then continued to descend below circuit height and the crew subsequently received an E/GPWS TERRAIN alert and conducted a climb.
The evidence collection phase of the investigation will involve the ATSB interviewing involved parties and reviewing recorded data, and the collection of other relevant information.
A final report will be released at the conclusion of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties, so that appropriate safety action can be taken.