On October 26, 1996, a Cessna 140 (registration N83N) was involved in an aviation accident near Wakefield, VA. Investigators recorded the probable cause as: uncommanded operation of the parking brake, due to a missing tension spring, which resulted in locked brakes and subsequent nose over of the airplane during landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a landing with calm wind, the airplane's main tire(s) locked, causing it to nose over. Investigation found a missing tension spring in the left master cylinder.
Approach and Landing
The pilot was conducting an approach to the airport with a passenger on board. Wind conditions were calm, and the pilot executed a standard traffic pattern. Upon touchdown, the main tire or tires locked, and the airplane subsequently nosed over.
Pilot Report
The pilot stated that the aircraft was configured for a three-point landing and that no warning or indication of an impending problem was observed prior to the incident.
Post-Accident Examination
An examination of the airplane revealed that the left master cylinder tension spring was missing. This component is designed to prevent the parking brake lock from engaging.