What happened
During cruise flight, the first officer notified the captain that he was feeling ill. In response, the captain took control of the aircraft. After a period of time, the first officer reported that his condition had improved and resumed his duties as pilot.
Approximately 30 minutes later, the medical symptoms returned. The captain assumed control of the aircraft once again and declared an emergency. As the flight was being diverted to Abilene, Texas, a passenger performed cardiopulmonary resuscitation (CPR) on the first officer. Despite these efforts, the first officer was pronounced dead at a local hospital.
Findings
An autopsy determined that the cause of death was ischemic heart disease. Additionally, a federal air surgeon identified evidence of an old myocardial infarction and noted a high probability that a recent myocardial infarction had occurred.