This sounds like the much(over) cited Expert System example of Campbell Soup Company mind melding with the really old guy that they flew all over the US fixing their soup cookers. They were terrified that he would retire or fall out.

<warstory>Took a trip to Alabama years ago to see a Unisys factory control system. Roll steel came in one end of the plant and steel buildings went out the other. Their major production problem was that the heat from the continous welding of the web on the I-beams tended to warp the beam. They had their own old guy who would walk the beam with a torch and a bucket of water. This "artist" would heat and cool spots on the beam and pull the warping out! He was training he son to take over from him.</warstory>

James