WPR22LA324

NTSB accident investigation · Champion 7GCBA · Athol, ID · August 23, 2022

Accident · No injuriesClass 3 · LimitedFinal report
Date
August 23, 2022, 09:30 local (16:30 UTC)
Place
Athol, ID
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9512SChampion 7GCBA
Defining event
Landing-landing roll: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FAA
FAA report
20220823014989A
Case key
105834

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The failure of the right brake due to a disconnected master cylinder piston rod, which led to the departure of the airplane from the runway surface. Contributing to the accident was the mechanic’s failure to adequately inspect the connection between the piston rod and rudder pedal.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Inspection: scheduled/routine inspectionPersonnel issues › Task performance · Maintenance personnelChampion 7GCBA: 1 caseAll aircraft: 167 casesProbable cause
Landing gear system: master cylinder/brake valveAircraft › Aircraft systems · Inadequate inspectionChampion 7GCBA: 1 caseAll aircraft: 21 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot of the tailwheel-equipped airplane reported that the accident flight was uneventful from takeoff to touchdown. However, during the landing roll, the right brake was inoperative, causing the airplane to veer to the left and off the runway surface into a ditch, which resulted in the right main landing gear collapsing and the right wing impacting terrain. A postaccident examination of the airplane revealed that the right brake master cylinder piston rod had disconnected from the right rudder pedal attach point, and that the cotter pin was missing from the clevis pin. The airplane had undergone a conversion to a hydraulic toe brake rudder assembly about 3 years before the accident. However, the investigation was unable to determine, from the available evidence for this accident investigation, if the cotter pin was not installed, improperly installed, or subsequently damaged. The airplane’s an annual inspection was accomplished 12 days and about 1.3 flight hours before the accident. The mechanic who performed the inspection stated that he inspected the right brake system but did not recall or notice if the cotter pin was installed in the clevis pin. Given the short interval between the inspection and the accident, it is likely that the mechanic failed to adequately inspect the connection of the right rudder pedal to its brake system.

Factual narrative

On August 23, 2022, about 0930 Pacific daylight time, a Champion 7GCBA airplane, N9512S, was substantially damaged when it was involved in an accident near Athol, Idaho. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the first flight of the day in the tailwheel airplane was uneventful. The second (accident) flight was also uneventful from takeoff to touchdown; during the landing roll, the right brake was inoperative, which resulted in the airplane veering to the left and off the runway surface into a ditch. The right main landing gear then collapsed, which caused the right wing to impact terrain. Postaccident examination of the airplane by a Federal Aviation Administration inspector revealed that right brake master cylinder piston rod had disconnected from the right rudder pedal assembly, and that the cotter pin was missing from the clevis pin that connected it. The clevis pin was located under the right-side floorboard. Minor wear and markings on the clevis pin cad plating were consistent with the pin being installed; no wear or markings were noted in the cotter pin hole. The cotter pin was not located. The left pedal was properly connected with a cotter pin. The airplane had undergone a conversion to a hydraulic toe brake rudder assembly in October 2019. According to the pilot, the airplane had flown about 12 hours since the conversion. The airplane’s annual inspection was accomplished 12 days and about 1.3 hours (tachometer time) before the accident. The mechanic who performed the inspection stated that he inspected the right brake system and did not recall or notice if a cotter pin was installed in the clevis pin. The mechanic further stated that, if he had noticed a missing or bad cotter pin, he would have replaced it.

Aircraft

Registration
N9512S
Reported as
Champion 7GCBA
Category
Airplane
Serial number
7GCBA21
Built
1965
Airframe hours
1,313.27
Engine
Lycoming O-320 SERIES, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Aerobatic; Standard, Normal
Last inspection
Annual · August 11, 2022
Departed
ID05 · Athol, ID
Airport
ID05 · Hackney Airpark, runway 21, 3,500 × 150 ft, grass/turf
Equipment
Video recording device, Handheld GPS

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
59
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
July 11, 2022
Seat
Front
Restraint
4-point
Flight hours
18,000 total · 200 in this make and model · 6,000 as pilot in command · 100 in the last 90 days · 2 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 54 °F
Altimeter
30.04 inHg
Observed at
KCOE, 13 nm away
METAR
KCOE 231656Z AUTO VRB03KT 10SM CLR 23/12 A3004 RMK AO2 SLP173 T02280122 PNO $

Docket · 7

The files NTSB released with the investigation on May 2, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 14.1 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.