Pilot Debrief

CESSNA 170B near Cameron Park, CA — 2023-11-27

Final reportWPR24LA045
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Date
2023-11-27
Location
Cameron Park, CA, USA
Airport
O61
Aircraft
CESSNA 170B
Registration
N170HT
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Landing

Probable cause

A failure of the right brake master cylinder piston due to a faulty return spring, which resulted in a seized right main landing gear brake and a runway excursion

NTSB narrative

The pilot was landing at his destination airport when the airplane veered to the left after touchdown. . The pilot attempted to correct the movement and turn the airplane back to the runway centerline with the addition of power and right rudder inputs, but the airplane then veered to the right and departed the right side of the runway. The pilot did not recall experiencing any mechanical anomalies with the brakes during the accident flight and observed normal resistance during the landing. Postaccident examination of the brake system revealed that the right brake master cylinder failed to release pressure twice during testing and the piston had to be manually lifted before the cylinder would release pressure, which the pilot was unlikely to have been able to do during landing. The seized brake master cylinder was likely due to a deformed return spring that had bowed at some point during its service life. The manufacturer reported that the failure of the cylinder to release pressure would have resulted in a locked brake. Although the pilot could not recall if he applied brakes, both his and the witness’ recollection that the airplane abruptly turned right and departed the runway suggests that he may have applied right brake as the airplane was veering left. During this time the piston likely failed to release pressure due to the faulty return spring, which resulted in a runway excursion.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Inspect brake system for anomalies before flight.

NTSB coding

Evidence available

  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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