Accident Overview
On November 3, 2020, at about 1235 Pacific daylight time, a Stinson 108-3, registration N6855M, sustained substantial damage during a landing at an airport in El Monte, California. The airplane was being operated under Title 14 Code of Federal Regulations Part 91 as an instructional flight. The flight instructor and the pilot receiving instruction were not injured.
Flight Sequence
According to the flight instructor, the purpose of the flight was to provide tailwheel instruction to a private pilot. The pilot receiving instruction performed three full-stop takeoffs and landings on runway 19. During the landing roll following the fourth landing, the airplane began to veer to the left. The instructor assumed the flight controls and applied rudder, but the airplane did not respond. The instructor then applied the right brake, and the airplane began to turn to the right. Subsequent application of left rudder produced no response. The airplane continued to turn to the right, and the left wing impacted the ground. The airplane came to rest facing the opposite direction and sustained substantial damage to the left wing and aileron.
Tailwheel Assembly Examination
The airplane was equipped with a Scott 3000 series tailwheel assembly. The design incorporated a swiveling steering arm connected to and controlled by the tailwheel steering yoke through a spring and a tension chain on both the left and right sides. The manufacturer’s instructions called for the spring to be connected directly to the tailwheel yoke, and the chain to be connected to the steering arm with a connector clip. Postaccident examination of the airplane revealed that both steering springs and chains had separated from both the tailwheel steering yoke and steering arm assembly. The tension chain connector clips were connected to the tailwheel steering yoke rather than the steering arm.
Component Recovery
Both steering springs were located on the runway after the accident. One spring was recovered near the runway 19 centerline about 230 feet beyond the runway threshold, and the second was recovered from the safety area on the left side of the runway about 1,900 feet beyond the threshold. The left and right tension chains were not located.
Maintenance History
According to the airplane’s maintenance logbooks, the most recent annual inspection was completed 7 flight hours prior to the accident.