A Boeing 737-204 aircraft, operated by COPA Panama, was destroyed when it crashed near Tucut¡, Panama. All 40 passengers and seven crew members were killed. COPA Flight 201 took off from runway 21L at Panama City-Tocumen International Airport at 20:36. Destination of the flight was Cali, Colombia. The flight intercepted Airway A321 and climbed to the cruising altitude of FL250. At 20:46 the flight contacted the Panama City controller and requested weather information. The controller reported that there was an area of very bad weather at 30-50 miles. Last radio contact was at 20:48 when the crew reported reaching FL250. During the flight there was an intermittent failure of the main attitude indicator due to a short circuit. This was not noticed by the flight crew, who attempted to adjust the aircraft attitude based on the false information from the attitude indicator. They lost control of the aircraft which entered a steep descent and started to disintegrate at FL100, and impacting the ground 80 degrees nose down. The probable causes of this accident include: a) loss of control of the aircraft because the flight crew followed false information from an attitude indicator that operated intermittently. b) lack of visible horizon during cruise flight due to night and approaching bad weather. c) insufficient cross-checking between the primary and emergency (stand-by) attitude indicators to identify intermittent attitude errors and to select a reliable source of (correct) attitude information. d) non-standard cabin configurations between aircraft in the fleet of the company, which required the crew to determine how to set the switches based on the aircraft was being operated at the time. e) incomplete ground crew training simulator, as it did not present “differences between aircraft” and “crew resource management” in sufficient detail to give the crew knowledge to overcome intermittent attitude indicator errors and to maintain control of the aircraft.