On March 29, 1995, approximately 1726 central standard time, a Douglas DC-9-32, N5342L, made an emergency landing at Abilene, Texas, after the first officer became incapacitated and subsequently expired. There were no injuries to the captain, three flight attendants, and 60 passengers, and the airplane was not damaged. The airplane was being operated by Grand Airways as a scheduled domestic passenger flight under 14 CFR Part 121 when the incident occurred. The flight originated at Phoenix, Arizona, on March 29, 1995, at 1115 mountain standard time. Visual meteorological conditions prevailed at the time and an IFR flight had been filed. Approximately 1630, while the airplane was cruising at FL330, the first officer told the captain he was ill. The captain assumed control of the airplane and summoned a flight attendant to the flight deck. The first officer donned his oxygen mask, but removed it shortly thereafter. Later, the first officer said his symptoms were passing and he resumed flying the airplane. Approximately 1655, as the airplane was descending to FL240, the first officer complained that he was beginning to feel sick again. The captain assumed control of the airplane and declared an emergency. As the airplane was diverted to Abilene, Texas, a passenger trained in CPR (cardiopulmonary resuscitation) examined the first officer, determined he had suffered a cardiac arrest, and began resuscitation. The airplane landed at 1725 and was met by paramedics. The first officer was subsequently pronounced dead on arrival at a local hospital (see Pilot/Operator report for additional information). An autopsy (AFC-046-95) was performed by Deputy Chief Medical Examiner Marc A. Krouse, M.D., of Anatomic and Forensic Pathology Consultants, in Fort Worth, Texas. Cause of death was attributed to ischemic heart disease. The report was reviewed by FAA's Southwest Regional Flight Surgeon, who noted there was evidence of an "old myocardial infarction" (heart attack), and a "high probability of a recent myocardial infarction." Toxicology protocol was conducted by FAA's Civil Aeromedical Institute (CAMI). According to CAMI's report, quinine was detected in the first officer's urine. According to a CAMI physician, quinine is an ingredient found in tonic water and various medications, including heart medication. The physician said the amount of quinine detected was "insignificant." A review of the first officer's most recent FAA physical examination, dated January 19, 1995, disclosed a blood pressure of 130/82, and a resting pulse of 80. EKG tracings were not enclosed. A former USAF pilot, the first officer's medical file included medical data from 1972. The only anomaly noted was Hodgkin's disease that was diagnosed in 1970 and treated. There was no evidence of a recurrence of symptoms.