Cessna 421C N71RC

Summary

On 7 January 2017 at about 01:20 local time, a Cessna 421C registered N71RC was involved in an accident near Jackson, California, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

7 January 2017 at 01:20

Classification

Accident

Location

Jackson, California, United States

Nearest airport

Westover Field Amador County (JAQ)

Coordinates

38.3769, -120.7942

Aircraft

Cessna 421C

Registration

N71RC

Category

Airplane

Year built

1977

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Palo Alto → Jackson

Aircraft damage

Substantial

Weather

VMC

Light

Dusk

NTSB number

WPR17LA051

Nobody was injured.

The failure of the right main landing gear torque link bolt in overstress, which resulted in the collapse of the landing gear during the landing roll.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The airline transport pilot reported that, during the landing roll at the end of a cross-country flight, when he attempted to lightly apply the brakes, the airplane began to yaw from side to side. The airplane subsequently exited the right side of the runway and sustained substantial damage to the right wing spar. During the landing, the right main landing gear collapsed. An on-site examination revealed that the right main landing gear torque link assembly had separated at the hinge attach point due to the failure of the torque link bolt. Although the bolt was located at the accident site, the bolt's nut, cotter pin, and washer were missing. Further examination revealed that the torque link bolt threads had been rounded over and exhibited remnants of material consistent with the threads of the mating nut. In addition, remnants of the cotter pin that was installed through the bolt hole were visible. The sheared cotter pin and threads from the nut that remained within the bolt threads suggest that the torque link bolt/nut assembly was overloaded, which resulted in the landing gear collapse. A Federal Aviation Administration special airworthiness information bulletin had been issued about 3 years before the accident to advise owners, operators, and maintenance technicians of the make and model airplane of the need to inspect the main landing gear torque link assembly to ensure the correct thickness of washers and to ensure that the washers are installed properly, and a Cessna service bulletin had also been issued previously regarding the washers. However, no maintenance records were available to determine the airplane's maintenance history or compliance with the applicable bulletins.

Quoted verbatim from the NTSB record.