Accident Overview
On November 27, 2023, at about 1305 Pacific standard time, a Cessna 170B, registration N170HT, sustained substantial damage during a landing accident near Cameron Park, California. The pilot and one passenger were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Account
The pilot reported completing four full-stop landings at a nearby airport before returning to Cameron Park Airport (O61). During the landing attempt at O61, the airplane touched down normally but immediately veered left. The pilot added power and applied rudder to correct, but the airplane then veered right and departed the right side of the runway. The pilot could not recall using brakes during the correction. Substantial damage occurred to the fuselage.
Witness Observation
A witness near midfield reported hearing the airplane engine before it came into view. The witness then heard the engine power increase and saw the main landing gear touch down with the tail wheel still airborne. The airplane veered right, and the right main landing gear struck a dirt berm before the airplane came to rest upright.
Brake System Examination
Per the pilot’s operating handbook, the airplane was equipped with conventional toe-type brake pedals at the top of the rudder pedals. Two brake master cylinders were mounted directly to the pilot’s hydraulic brake pedals. Braking is achieved by applying toe pressure to the rudder pedals, actuating the master cylinders to apply braking action on the main landing gear wheels.
Examination of the brake system revealed no mechanical anomalies with the left and right main landing gear brake calipers. The left brake master cylinder functioned normally when tested. The right brake master cylinder failed to release pressure when tested twice; the piston had to be manually raised before pressure released. Disassembly of the right brake master cylinder showed the piston return spring was deformed (bowed). According to the manufacturer, failure of the cylinder to release pressure would have resulted in a locked brake.
Maintenance Records Review
Review of the airplane’s maintenance records from 2002 to the accident date indicated that on June 20, 2015, the airplane underwent repair of the pilot-side right brake master cylinder attachment area by installing a doubler. At that time, the shafts of both brake master cylinders were replaced along with O-rings. The pilot-side left brake master cylinder was replaced on July 13, 2016. There was no maintenance requirement for inspection or replacement of the return spring, and no indication in the records that the return spring had ever been replaced. Federal Aviation Regulations Part 43 Appendix D lists “brakes – for improper adjustment” as required inspection items for annual and 100-hour inspections.
Pilot Brake Assessment
The pilot stated that the brakes felt normal during preflight testing before the accident flight. He noted feeling resistance on the brakes, with neither feeling mushy when he activated them upon touchdown and lost directional control. He also had performed a full-stop landing at the nearby airport earlier without any brake issues.