Casualties unknown

1999-10-15: Cessna 172G (N4621L) — Cambridge, MN

Cambridge, MN, US

On October 15, 1999, a Cessna 172G (registration N4621L) was involved in an aviation accident near Cambridge, MN. Investigators recorded the probable cause as: the fractured main landing gear due to the improper maintenance by an unknown person(s) and the inadequate annual inspection by an unqualified person. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A Cessna 172G impacted the runway during landing after losing directional control. Investigation revealed a fractured weld on the right main landing gear strut, where the cabin entry step had been welded instead of attached with adhesive as per the service manual.

Incident Overview

A Cessna 172G impacted the runway during landing following a loss of directional control. The incident was investigated, and findings centered on the right main landing gear strut.

Landing Gear Examination

Inspection of the right main landing gear revealed that the cabin entry step was welded on the bottom side of the strut. The strut had fractured at the weld attaching the step to the strut. Similarly, the cabin entry step on the left main landing gear strut was also welded to its strut.

Maintenance Documentation

There was no logbook entry regarding the welding of the cabin entry step on either landing gear strut. Additionally, the last annual inspection was not performed by an Inspection Authorized (IA) airframe and powerplant mechanic.

Manufacturer's Specifications

The Cessna Service Manual, under section 5-7, Step Bracket Replacement, states: "The step bracket is secured to the landing gear strut with Conley-Weld, or a similar epoxy base adhesive." The manual does not specify welding as an approved attachment method.

Conclusion

The incident involved a loss of directional control during landing, with the right main landing gear strut having fractured at a weld. The welding of the cabin entry step deviated from the manufacturer's recommended adhesive attachment method.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X19921. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.