On January 18, 1989, a Cessna 190 (registration N1058D) was involved in an aviation accident near Sonoma, CA. Investigators recorded the probable cause as: The pilot's inability to maintain directional control during the landing roll, which resulted from a clip breaking free and jamming in the left main gear brake mechanism. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft veered left during landing roll and nosed over after a clip broke free in the left main gear brake, jamming between the disc housing and wheel hub.
What happened
The incident occurred while the pilot was practicing touch-and-go landings. During the landing roll of one such maneuver, the airplane began to veer significantly to the left. The pilot attempted to correct the trajectory but was unable to maintain directional control of the aircraft. As a result, the airplane exited the paved surface and subsequently nosed over.
The investigation
Following the accident, investigators examined the landing gear assembly to determine the mechanical cause of the loss of control. Inspection of the left main gear brake mechanism revealed a critical failure. A retention clip had broken free from its intended position and become lodged between the disc housing and the wheel hub. This jamming prevented the brake system from functioning correctly, contributing to the asymmetric braking or drag that led to the veer.
Findings
The primary factor in this accident was the mechanical failure of the left main gear brake assembly. The dislodged clip created a physical obstruction that compromised the pilot's ability to steer the aircraft during the high-speed ground roll. This event highlights the importance of regular maintenance checks on landing gear components, particularly small retention hardware that can fail due to fatigue or vibration.
Probable cause
The pilot's inability to maintain directional control during the landing roll, which resulted from a clip breaking free and jamming in the left main gear brake mechanism.