Cessna 170B N2766D

Summary

On 8 November 2017 at about 22:30 local time, a Cessna 170B registered N2766D was involved in an accident near Harvard, Illinois, 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

8 November 2017 at 22:30

Classification

Accident

Location

Harvard, Illinois, United States

Nearest airport

Dacy Airport (0C0)

Coordinates

42.4022, -88.6322

Aircraft

Cessna 170B

Registration

N2766D

Category

Airplane

Year built

1952

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Poplar Grove → Harvard

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN18LA044

Nobody was injured.

The failure of the universal joint in the pilot-side flight control yoke due to the fatigue fracture of a rivet within the universal joint. Contributing to the universal joint failure was the universal joint design, which was prone to galling wear and seizure. 

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

Read the full NTSB narrative

The private pilot was conducting a personal flight. He reported that he experienced a "complete loss of flight controls" during the landing flare. The main landing gear settled to the runway; during the landing roll, the pilot was able to reach the copilot-side control yoke and completed the landing, but the airplane received substantial damage. A postaccident examination of the airplane revealed that the rivet in the universal joint for the pilot-side control yoke had failed, causing the universal joint to disassemble. The examination of the universal joint also revealed that the assembly seized and would not articulate as designed. The assembly seized due to galling wear between the center pin and the yoke ear holes and between the swivel blocks and the yoke ears, resulting in high alternating stresses in the rivet that held the half pins in place. The high alternative stresses in the rivet caused the rivet to fail by low-cycle reversed-bending fatigue fracture. The universal joint design was prone to galling wear and seizure. Maintenance records indicated the universal joint had been replaced 1.5 years before the accident and had acquired 199.1 hours of flight time since being installed. The component had been maintained in accordance with the requirements prescribed in the airframe manufacturer's service manual. No evidence suggested that the failure was related to improper maintenance or lubrication.

Quoted verbatim from the NTSB record.