Primary finding
Probable cause
The failure of the left main landing gear leg due to fatigue. Contributing to the incident was maintenance personnel's failure to completely remove all corrosion before repainting the gear leg.
Investigator assessment
Analysis narrative
The pilot was landing the tailwheel-equipped airplane on a dry paved runway. He stated that just after touchdown, he heard a noise and felt the airplane pull to the left. He tried to abort the landing, but noted that the left main landing gear had separated from the fuselage, so he landed the airplane in the grassy area adjacent to the runway. During the landing the airplane sustained minor damage. The spring steel left main landing gear assembly was fractured about 5 inches from the fuselage attach point. Postaccident metallurgical examination revealed that the landing gear leg fractured due to fatigue that initiated from pits on the lower surface of the leg. The pits were filled with brown paint that was covered with white paint. Therefore, it is likely that the pits were formed by corrosion that was not completely removed before the gear leg was repainted.
Source record
Factual narrative
On July 29, 2012, about 1400 Alaska daylight time, a Bellanca 8KCAB airplane, N5026B, sustained minor damage during landing at the Homer Airport, Homer, Alaska. The solo airline transport rated pilot was not injured. The airplane was being operated as a 14 Code of Federal Regulations Part 91 personal flight when the incident occurred. Visual meteorological conditions prevailed, and no flight plan was filed. In an interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on August 8, the pilot stated that just after touchdown on the dry paved runway, he heard a noise and felt the airplane pull to the left. He lifted the airplane off the runway, and noticed that the left main landing gear had separated from the fuselage. He elected to immediately land the airplane in the grass safety area adjacent to the runway. The spring steel left main landing gear assembly was fractured approximately 5 inches from the fuselage attach point. An examination of the landing gear assembly was performed by the NTSB Materials Laboratory, and revealed the gear leg fractured due to fatigue that initiated from pits on the lower surface of the leg. The pits were filled with brown paint, and the brown paint was covered with white paint. A complete copy of the NTSB's materials laboratory factual report is included in the public docket for this accident. The pilot did not complete a NTSB Accident/Incident Reporting Form 6120.1.