What happened
On January 6, 2020, a Cessna 172H, registration N1612F, crashed near Newborn, Georgia, resulting in 1 fatality.
The flight originated from Toccoa Airport-RG Letourleau Field (TOC) at approximately 12:30, with a planned destination of Cairo-Grady County Airport (70J). Radar data from the FAA indicated that about one hour into the flight, the aircraft began a meandering flight path near Newborn. The aircraft performed several left and right 360-degree turns and continued through 13 consecutive right 360-degree turns while progressing in an easterly direction. Witnesses reported seeing the airplane flying at a low altitude and circling before it descended below the tree line. The aircraft impacted the terrain, and a post-impact fire occurred.
The investigation
Engine examination revealed no mechanical anomalies that would have prevented normal operation. However, investigators found that the right muffler and shroud exhibited substantial mechanical damage, including cracks and through-thickness metal wastage. The center inlet tube had separated from the muffler due to a loss of mechanical integrity. This degradation likely allowed exhaust gases and carbon monoxide to enter the cabin.
Post-accident toxicology testing of the pilot revealed carboxyhemoglobin levels between 48% and 61%. Carbon monoxide levels of 40% or higher are known to cause confusion, seizures, loss of consciousness, and death. Additionally, the pilot's medical history included coronary artery disease, which likely increased his susceptibility to the effects of the gas.
Maintenance records showed that while the left muffler had been replaced approximately 10 years prior, there was no documentation regarding the installation or maintenance of the right muffler. The aircraft was also overdue for its annual inspection.