Casualties unknown

Wheel Assembly Separates During Takeoff from Lubbock (N309SW)

Lubbock, TX, US

On August 18, 1995, a Boeing 737-3H4 (registration N309SW) was involved in an aviation accident near Lubbock, TX. Investigators recorded the probable cause as: An incorrect inner bearing was inadvertently installed by the wheel assembly supplier on the number three wheel assembly. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards
Boeing 737-3H4
Photo: San Diego Air & Space Museum Archives / Public domain, via Wikimedia Commons

During takeoff at Lubbock, Texas, the number three wheel assembly separated from the axle. The flight continued to Albuquerque, New Mexico, where it landed uneventfully. Investigation revealed an incorrect bearing had been installed by the supplier.

Incident Overview

During takeoff from Lubbock, Texas, the number three wheel assembly separated from the axle of an aircraft. The aircrew continued the flight to Albuquerque, New Mexico, where the aircraft landed without further incident.

Maintenance History

Company maintenance records indicated that the wheel assembly had last been replaced on August 16, 1995.

Examination Findings

Post-flight examination of the aircraft revealed that the axle nut was intact on the axle along with the tang washer. The axle nut locking ring was also found in place. The outer bearing had deteriorated, with only its inner race remaining, while the inner bearing remained intact on the axle.

Further examination of the components determined that an incorrect inner bearing had been installed inadvertently by the wheel assembly supplier on the number three wheel assembly. Specifically, a Timken part number 594 bearing was installed in place of the correct Timken part number 596 bearing.

Probable cause

An incorrect inner bearing was inadvertently installed by the wheel assembly supplier on the number three wheel assembly.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001207X04228. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.