Piedmont Airlines flight 349 was a scheduled service from Washington-National Airport, DC to Roanoke, Virginia, with intermediate stops at Charlottesville and Lynchburg, Virginia. The DC-3 departed Washington-National Airport at 19:49 hours local time. The flight was according to an instrument flight plan and clearance which specified a routing over airway V-140 and a cruising altitude of 4000 feet. The aircraft flew a heading of 260ø on airway V-140, but did not turn left to 239ø over the Casanova VOR to continue on the airway. Instead it remained on the same heading. It began the instrument approach to Charlottesville 8 to 11 miles west of the manoeuvring area prescribed by the instrument approach procedure. During the inbound portion of the procedure turn the aircraft struck the rocky slope of a 3100 feet mountain at an elevation of about 2600 feet. The investigators learned that the captain of the flight was suffering from serious emotional and mental stress episodes since 1953. He was under psychotherapy at the time of the accident and his last appointment was the night before the accident. He was likely taking Prozine in the period leading up to the accident, an antipsychotic medicine. The investigation board stated that the investigation of this accident demonstrated the need for re-examination of the use of drugs that might affect the capabilities of a flight crew member. The Board noted that several psychopharmacological drugs had been developed since 1953-1954, which should be considered falling under section of the Civil Air Regulation covering the use of drugs. In any case, the Board concluded that “if a flight crew member’s personal situation demands tranquilizers he should be removed from flying status while on the drugs.” PROBABLE CAUSE: “A navigational omission which resulted in a lateral course error that was not detected and corrected through precision instrument flying procedures. A contributing factor to the accident may have been pre-occupation of the captain resulting from mental stress.”