Accident Overview
On March 29, 2020, at approximately 1142 mountain standard time, a Cessna 172, registration N172FG, sustained substantial damage during a landing accident at Sedona Airport (SEZ), Sedona, Arizona. The pilot and passenger were not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight and Landing Sequence
The pilot had departed from Glendale, Arizona, with Sedona as the planned destination. Approaching from the east, the pilot overflew the airport and noted that the windsock indicated runway 21 as the active runway. The pilot reported an airspeed of 68 to 70 knots on final approach with flaps set to 30 degrees. After touchdown, just beyond the 1,000-foot markers on runway 21, the airplane experienced a sudden 40-degree left swing. The pilot applied full right rudder and braking, but the airplane continued to veer left, exiting the paved runway surface. Once off the runway, the nosewheel dug into soft dirt, causing the airplane to flip over.
Wind Conditions
The pilot reported the wind at the time of the accident was from 130 degrees at 9 knots with variable gusts. A witness described the wind as "very gusty and shifting" during the landing. The witness also observed the airplane touch down on its nose gear, then veer left and nose over after leaving the runway.
Post-Accident Findings
Following the accident, the pilot obtained photographs of the nose gear fork, which showed "severe corrosion and cracks" at the location where the nose landing gear failed. The pilot stated that these photographs were reviewed by a Federal Aviation Administration repair station in California, and their representative indicated the part was "severely compromised and unairworthy." The pilot opined that these issues caused the airplane to swerve off the runway.
The nose landing gear fork was sent to the National Transportation Safety Board (NTSB) materials laboratory for examination. The NTSB materials engineer reported that the fracture features of the fork were indicative of an overstress fracture. Both microscopic and macroscopic features were consistent with fracture from overstress in bending, with the bending direction upward, which aligns with the load profile expected during a landing on the downward-oriented fork. Importantly, the NTSB engineer found no indications of pre-existing damage, such as cracking or corrosion, that would have contributed to premature fracture.