N172FGCessna 172N · 1976

On March 29, 2020, about 1142 mountain standard time, a Cessna 172, N172FG, was substantially damaged when it was involved in an accident at Sedona Airport (SEZ), Sedona, Arizona. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot departed Glendale, Arizona, with a planned destination of Sedona. The pilot approached Sedona from the east, overflew the airport, and observed that the windsock favored runway 21. The pilot reported the airspeed on final was “68-70 knots” and the flaps were set to 30°. The pilot reported that immediately after touchdown, just beyond the 1,000’ markers of runway 21, the airplane “took a violent 40° swing to the left.” The pilot stated full right rudder and brakes were applied to correct the situation; however, the airplane continued to veer and exited the paved runway surface. The pilot stated that after the airplane exited the runway, its nosewheel dug deep into the soft dirt, and the airplane flipped over.

The pilot reported the wind at the time of the accident was 130° at 9 knots, with variable gusts. A witness stated the wind was “…very gusty and shifting” when the airplane landed. The witness stated that the airplane touched down on its nose gear, veered left, and nosed over after exiting the runway.

Following the accident, the pilot reported that photographs of the nose gear fork “showed severe corrosion and cracks” where the nose landing gear failed. The pilot stated that the photographs were subsequently reviewed by a Federal Aviation Administration repair station, in California, and their representative stated the “part [nose gear fork] was severely compromised and unairworthy.” The pilot opined that these findings 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 and inspection. The NTSB materials engineer who examined the components reported that the nose landing gear fork fracture features were indicative of fracture from overstress and that microscopic and macroscopic features were consistent with fracture from overstress in bending. The bending direction was upward, which would be consistent with the load profile expected during a landing of the downward-oriented fork. The NTSB materials engineer also reported that there were no indications of any pre-existing damage, such as cracking or corrosion, that would have contributed to premature fracture.