From an article in New Scientist for Dec 29, 2001, p. 58

During WWII a number of US warplanes en route from Labrador to Iceland were forced by storm to land on Greenland. All the airmen survived, but the planes sank into the ice, until by now they are 80 meters, about 250 feet below the surface. A team of adventurers has recovered one of the P-38s. After managing to find the location, they sank a shaft down to the plane, and then descended to it by "abseiling" down to it. I knew this was a rock climbing term, and found a site of rock climbing terminology.
Perhaps the terms might be worth discussing.
http://www.theclimbershub.co.uk/dictionary/dictionary.asp?Term=abseil