Controlled flight into terrain (CFIT) is a term developed by engineers at Boeing in the late 1970s. It describes an accident whereby an airworthy aircraft, under complete control of the pilot(s), inadvertently flies into terrain (or an obstacle, or water). The pilots are generally unaware of the danger until it is too late. In civil and especially private aviation, CFIT may be humorously referred to as rock-filled cloud or 'cumulogranite' when it is caused by terrain being obscured by clouds. More target=_blank>http://en.wikipedia.org/wiki/CFIT> here