Summary
On January 23, 2023, a Cessna 170 (N9534A) was involved in an incident near Mesa, AZ. All 3 people aboard were uninjured. The aircraft sustained substantial damage.
The National Transportation Safety Board determined the probable cause of this incident to be: The pilot’s failure to maintain directional control during the landing roll out and the preexisting fatigue cracks in the left main landing gear leg, which resulted in the leg’s premature overstress fracture during the ground loop.
On January 23, 2023, about 1630 mountain standard time, a Cessna 170A, N9534A, sustained substantial damage when it was involved in an accident near Mesa, Arizona. The pilot, flight instructor, and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the pilot receiving instruction, he was conducting takeoffs and landings to regain tailwheel currency. During the landing roll after the second landing, the airplane began to veer to the left. He applied correction with right rudder; however, he overcorrected and the airplane veered to the right. The pilot receiving instruction and the flight instructor both applied left rudder and brake to counteract the veer to the right.
This incident is documented in NTSB report WPR23LA096. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N9534A.
Accident Details
Probable Cause and Findings
The pilot’s failure to maintain directional control during the landing roll out and the preexisting fatigue cracks in the left main landing gear leg, which resulted in the leg’s premature overstress fracture during the ground loop.
Aircraft Information
Registered Owner (Current)
Analysis
On January 23, 2023, about 1630 mountain standard time, a Cessna 170A, N9534A, sustained substantial damage when it was involved in an accident near Mesa, Arizona. The pilot, flight instructor, and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
According to the pilot receiving instruction, he was conducting takeoffs and landings to regain tailwheel currency. During the landing roll after the second landing, the airplane began to veer to the left. He applied correction with right rudder; however, he overcorrected and the airplane veered to the right. The pilot receiving instruction and the flight instructor both applied left rudder and brake to counteract the veer to the right. Despite their corrections, the airplane ground looped to the right. During the ground loop, the left main landing gear leg fractured mid span, near the brake line retainer clip bore, and the left wing contacted the runway surface.
Postaccident examination and fracture analysis of the left main landing gear leg was conducted by the National Transportation Safety Board Materials Laboratory. The examination revealed that the landing gear failed in its final landing due to small fatigue cracks present along the radius of the retainer clip bore and the outboard face. Outside the fatigue cracks, the fracture surface exhibited features consistent with overstress fracture. The fatigue cracks initiated at small corrosion pits along the radius of the bore, and propagated until the final landing, when the remainder of the leg fractured from overstress.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# WPR23LA096