We are always on the lookout for people with specific skill sets that can help us during future field campaigns. Do you have field experience in Greenland or other remote regions? If you’d like to join us during the 2021 field season (NH spring/summer), then tell us you’re available here: https://greenlandguidance.com/about-us/join-us/. If you’re on the list, we’ll know how to find you.
Here’s a very nice 30-minute documentary by talented Arnar Ingi Gunnarsson on the 2019 recovery of the Airbus engine part lost over the Greenland ice sheet. Greenland Guidance was part of the challenging fan hub recovery after a long and difficult search by GEUS, ONERA – The French Aerospace Lab, Aarhus University and Polar Research Equipment. Recently BEA-É | Bureau enquêtes accidents pour la sécurité de l’aéronautique d’État finished their investigation looking into the causes of the accident – with some interesting findings (check out their website). Greenland Guidance thanks Airbus, Air France and Engine Alliance for the excellent collaboration.
Following our project of recovering a part from an Airbus A380 airplane engine from the Greenland ice sheet last year, we wrote a paper detailing our methods. The part was crucial for determining what went wrong on that flight over Greenland in 2017. Read the paper by Ken Mankoff and coauthors in the Journal of Glaciology here: http://dx.doi.org/10.1017/jog.2020.26.
On 30 September 2017, an Air France Airbus A380-800 suffered a failure of its fourth engine while over Greenland. This failure resulted in the loss of the engine fan hub, fan blades and surrounding structure. An initial search recovered 30 pieces of light debris, but the primary part of interest, a ~220 kg titanium fan hub, was not recovered because it had a different fall trajectory than the light debris, impacted into the ice-sheet’s snow surface, and was quickly covered by drifting snow. Here we describe the methods used for the detection of the fan hub and details of the field campaigns. The search area included two crevasse fields of at least 50 snow-covered crevasses 1 to ~30 m wide with similar snow bridge thicknesses. After 21 months and six campaigns, using airborne synthetic aperture radar, ground-penetrating radar, transient electromagnetics and an autonomous vehicle to survey the crevasse fields, the fan hub was found within ~1 m of a crevasse at a depth of ~3.3 to 4 m and was excavated with shovels, chain saws, an electric winch, sleds and a gasoline heater, by workers using fall-arrest systems.
In September 2017, an Air France flight traveling west over the Greenland ice sheet experienced a failure in its 4th engine. All on board were unharmed, and the plane landed safely in Goose Bay, Canada. To figure out what exactly went wrong with the engine, a search for the missing engine parts was executed by the Geological Survey of Denmark and Greenland (GEUS) supported by Greenland Guidance.
The torn-away parts of the airplane engine dropped onto the ice sheet, but the heavy pieces of the fan hub – needed for the investigation – impacted into the snow surface and were lost from sight almost instantly, getting buried further with every subsequent snowfall event high on the ice sheet. The search for the largest and potentially most interesting part was difficult due to severe storms, snow-covered crevasses in the region, and the ever-present risk of polar bears passing by. Guided to a few promising sites by airplane-based radar measurements performed by ONERA (the French aerospace lab), the initial ground-based detection and therefore exact localisation was done by a radar-equipped robot (!) operated by Polar Research Equipment (PRE). The robot was crucial in regions too dangerous for people to tread unsecured, because of crevasses in excess of 10 m wide, yet invisible to the eye due to the snow cover. It wasn’t until the very end of the 3rd field campaign in spring 2019 that a metal detector custom-built by the Aarhus University HydroGeophysics Group clearly detected metal a few meters below the surface.
Greenland Guidance took part in the 4th recovery expedition to the ice sheet, bringing 3 experienced mountaineers from the Icelandic Association for Search and Rescue (ICE-SAR) to the scene. The expedition commenced on 28 June 2019, transporting as many as would fit in an AS350 Air Greenland helicopter (5 people) to the dig site. In spite of all safety precautions (mostly related to digging in a crevassed region), we made good progress. By the end of the second afternoon, we struck titanium. Eager to liberate the part, we kept working until after midnight. But melting the engine part loose and lifting it to the ice sheet surface proved very difficult, as we wanted to avoid contact with the yet-to-be-investigated part as much as possible. On 30 June, after an estimated 20 hours of digging, melting and lifting, the job was done and all returned safely to Narsarsuaq, 100 km southeast of where the engine part had impacted.
Find the GEUS press release here.