Missing airplane engine part found by GEUS led expeditions

Published 01-07-2019

GEUS led expeditions have helped locate and recover a missing piece of the A380-800 airplane engine from the Air France Flight 66 that passed over Greenland on 30 September 2017. This has been done in cooperation with French ONERA and others.

During the last two years, The Geological Survey of Denmark and Greenland (GEUS) has led four field campaigns to the Greenlandic Ice Sheet on behalf of the Danish and French safety investigation authorities, searching for the missing engine part, based on the extensive experience working on the ice and in Greenland.

“The search phase involved more than 13 weeks in Greenland, with seven weeks camping on the ice sheet, working in a crevasse field by foot, snowmobile, and robot, night-time operations, risk of polar bears, temperatures down to -35°C, and wind storms up to 25 m/s, with gusts up to 32 m/s,” explains field team leader Ken Mankoff, Senior Researcher at GEUS.

Preparation for the field campaigns involved additional fieldwork in Iceland, Switzerland, Sweden, and Denmark testing the sensors and practicing for the crevasse-field work.

Success

And all the work payed off. The search began with a 3 km by 5 km area but focused on a few points in Southern Greenland identified from an airborne search by the French Aerospace Lab ONERA.

“For this year’s search we invited Polar Research Equipment and their FrostyBoy robot to help us work safely in the crevasse field. We also invited the Aarhus University HydroGeophysics Group to join us with their Transient ElectroMagnetic instrument (TEM) which is normally used for mapping groundwater. Aarhus built a custom version, SnowTEM, that we could tow by snowmobile over the ice. Both FrostyBoy and the SnowTEM detected the part,” says Kenneth Mankoff.

The missing piece, a ~150 kg piece of titanium about 1 m ³ was found buried under ~4 m of snow and ice on the Greenland Ice Sheet and in the middle of a crevasse field. Crevasses were located less than 2 m from the part and some in the surrounding field were 30 m wide.

All crevasses were snow-covered, making them invisible to the search and recovery team working among them, but the team was still able to move safely in the area thanks to the FrostyBoy robot and its Ground Penetrating Radar (GPR) used to detect and mark the crevasses. FrostyBoy was built and operated by Polar Research Equipment.

Location of crevasses and point of maximum signal strength with red. Photo: Thue Bording.

Anton Adalsteinson of ICE-SAR FBSR melting out the fan hub. Photo: Dirk van As, Greenland Guidance.

Challenging field work

The extraction phase involved two days of camping, digging, and melting on a small island of solid ice in the middle of the crevasse field. The team used chainsaws, shovels, an electric hoist, and a heater to dig down to and melt the part out of the ice.

Members of the Iceland Search and Rescue (ISAR) team helped extract the part. Logistic support for the campaigns was provided by Greenland Guidance. Helicopter flights were provided by Air Greenland. The work was ordered by the Danish and French safety investigation authorities, and the French will supervise the further analysis of the found piece.

“Locating and recovering the part was made possible with the help of many talented individuals from all of the organizations involved,” says Ken Mankoff.