TAT Flight 230 departed Nancy, France, at 06:53 hours for Paris-Orly and climbed to a cruising altitude of FL140. At 07:26 the aircraft was cleared to descend to FL90 and later FL70. Approaching the MEL VOR, clearance was given to descend further to FL60. About 07:37 the aircraft entered a steep descent at a rate of 16000 ft/min. Twenty seconds later the aircraft struck power lines and impacted the ground. PROBABLE CAUSE (translated from original French language report): Immediately after an electrical systems failure occurred in instrument weather conditions, the aircraft pitched nose down. The Committee was unable to acquire any certainty as to the cause of this catastrophic descent. After eliminating various assumptions invalidated by the established facts and findings and after reviewing the results of flight tests conducted at its request, the commission assigned higher probability to the hypothesis that the electrical fault caused a loss of attitude reference and autopilot disconnect which would have occurred while the aircraft was configured ‘out of trim’ in a nose down attitude. In the absence of independent standby horizon, the crew had no usable attitude reference immediately available while the aircraft was in a high-speed dive.