On August 15, 1995, a Cessna 185A (registration N4145Y) was involved in an aviation accident near Teller, AK. Investigators recorded the probable cause as: DEFLATION OF THE LEFT MAIN TUNDRA TIRE DUE TO VALVE STEM DAMAGE (FAILURE) WHEN THE TIRE ROTATED INDEPENDENTLY OF THE WHEEL RIM, RESULTING IN LOSS OF DIRECTIONAL CONTROL AND A GROUND SWERVE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A commercial pilot and three passengers were landing at a Coast Guard station when the left main tire suddenly deflated, causing a ground loop. The aircraft sustained damage to the left wing, aileron, and horizontal stabilizer. Inspection revealed the tire had rotated independently from the wheel rim, damaging the valve stem.
Incident Overview
A certificated commercial pilot and three passengers were landing at a Coast Guard station to begin work. The runway, constructed of asphalt, had a length of 4,500 feet. The airplane was equipped with large tundra tires fitted with larger than standard wheel adapters.
During the landing roll, the left main tire suddenly deflated. This loss of tire pressure caused the airplane to ground loop. The ground loop resulted in damage to the left wing, left aileron, and left horizontal stabilizer.
Inspection Findings
An inspection of the left main tire revealed that it had rotated independently from the wheel rim along the tire bead. This rotation damaged the tire tube valve stem, leading to the deflation of the tire.