"Controlled flight into terrain" (CFIT) is a class of accidents in which an aircraft is flown under control into terrain or man-made structures. CFIT accidents typically result from pilot error or of navigational system error. Failure to protect ILS critical areas can also cause CFIT accidents. In December 1995, American Airlines Flight 965 tracked off course while approaching Cali, Colombia and hit a mountainside despite a terrain awareness and warning system (TAWS) terrain warning in the cockpit and desperate pilot attempt to gain altitude after the warning. Crew position awareness and monitoring of navigational systems are essential to the prevention of CFIT accidents. , over 40,000 aircraft had enhanced TAWS installed, and they had flown over 800 million hours without a CFIT accident.