A native of Delaware, Pettyjohn graduated from the University of Delaware with a Bachelor of Science in civil engineering and entered the U.S. Army as a 2nd lieutenant in the Corps of Engineers serving in Korea. Following his return, he received his medical degree from Hahnemann University School of Medicine in Philadelphia.
Pettyjohn served in Vietnam as a flight surgeon for the 17th Combat Aviation Group in 1966. On his return, he completed his internal medicine residency and cardiology fellowship at Madigan Army Medical Center in Fort Lewis, Washington. He completed a postdoctoral fellowship in public health/preventive medicine at the University of Washington in Seattle. He also completed a residency in aerospace medicine at Brooks Air Force Base in San Antonio.
Pettyjohn was a cardiologist and flight surgeon for Operation Homecoming to return Vietnam POWs to the United States in 1973. He joined the U.S. Army Aeromedical Research Laboratory at Fort Rucker, Alabama, conducting research in the fields of aeromedical evacuation, oxygen systems, trauma and altitude physiology. He continued his research at the Naval Aeromedical Research Laboratory in Pensacola, Florida.
Upon leaving military service, he joined the Whiddon College of Medicine at the University of South Alabama in 1989 as professor and founding chair of the Department of Emergency Medicine. He also served as chief of the cardiology division from 2001 to 2008.
Pettyjohn was recalled to the U.S. Army in 1991 as a cardiologist and aviation medicine consultant at the U.S. Army Aeromedical Center during Operation Desert Shield/Desert Storm. He was a member of the aeromedical team that returned POWs from Desert Storm to the United States. In December 2008, he again returned to active duty in the U.S. Army as a flight surgeon and cardiologist with the 345th Combat Support Hospital in Tikrit, Iraq.
He was board certified in internal medicine, cardiovascular disease, preventive medicine (aerospace medicine) and emergency medicine. He retired as professor emeritus from the University of South Alabama in 2017. Beginning in 2018, he was a member of the Board of Directors of the University of South Alabama Foundation.
Pettyjohn will be laid to rest in a private ceremony with full military honors at Barrancas National Cemetery onboard NAS Pensacola. A celebration to honor his life and military service will be held from 1 to 4 p.m. Jan. 14, 2023, at Felix’s Restaurant, 400 Quietwater Beach Road, Pensacola Beach, FL.
