On the afternoon of the 23rd of October, 2021, Alpine Cliff Rescue (ACR) were tasked with the rescue of two climbers stranded on Mt Rolleston, one of the highest peaks in Arthurs Pass National Park.
An unsuccessful rescue attempt had been made the previous night.
Anna Brooke and Michael Smith from ACR joined GCH Aviation helicopter pilots Henry Deans, Angus Taylor and Jeffrey Davies for the rescue.
The helicopter was stripped back to bare essentials for flying in the alpine environment.
Freezing levels on the mountain were rising, and several loose wet avalanches were observed.
Winching the rescue team members to the ground was challenging because of wind gusts, a low reference environment for the pilot winchman, the unknown stability and angle of the mountainside, and the proximity of a large bluff.
Weather conditions were not improving, so there was a possibility that the helicopter would not be able to return.
Braving white-out conditions, Anna Brooke and Michael Smith had to use all their technical skills to locate the climbers, who were in an improvised small snow-shelter on the summit, without any overnight equipment.
Ms Brooke and Mr Smith guided the climbers to the lower Crow Glacier to wait for the helicopter to return.
The conditions deteriorated, with higher wind speeds and colder temperatures. A lower cloud base was flowing down the Crow Glacier, and the weather was expected to deteriorate still further that evening.
After several circuits of the area, Angus Taylor spotted the party dug into a snow trench, 50 metres above a large bluff.
A landing or hover pick-up was not possible, because of the angle of the mountainside.
The climbers were winched out of the snow trench into the helicopter, but the cloud then descended further, making it impossible to locate Ms Brooke and Mr Smith.
They descended to a lower protruding snow-covered outcrop directly above a hundred-metre-plus bluff.
Two more attempts were made to reach them, but the cloud base remained too low.
When there was a break in the weather, the pair could be seen on the snowy outcrop.
They spread coffee over the fresh snow to give the pilots reference definition on the slope, for main rotor clearance.
The rescue team were then pulled onboard the helicopter before the cloud blew back down the valley.
This mountain rescue was a team effort in a precarious situation for everyone involved.
The team were pushed to the limits, but acted within appropriate safety parameters in order to save the lives of two inadequately equipped trampers.