Primary finding
Probable cause
The collapse/deflation of the right main tire when the tire slipped on the tire wheel rim which resulted in the collapse of the right main landing gear due to overload.
Investigator assessment
Analysis narrative
The pilot was landing the tailwheel-equipped airplane in a remote area. The airplane was equipped with oversize tundra type tires inflated to about 12 PSI. An adhesive, applied between the main wheel rim and the tire, helps to prevent the tire from rotating independent of the wheel. The pilot indicated that during the landing roll on grassy terrain, the right tire rotated away from the wheel rim. The tire deflated and began vibrating. The right main landing gear then collapsed, and the right wing struck the ground.
Source record
Factual narrative
On September 2, 1997, about 1700 Alaska daylight time, a tundra tire equipped Cessna 185, N185QB, crashed during landing at a remote area, about 30 miles north of Kotzebue, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight when the accident occurred. The airplane, operated by the pilot, sustained substantial damage. The certificated airline transport pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. A Federal Aviation Administration (FAA) inspector, Fairbanks Flight Standards District Office (FSDO), reported the airplane was damaged during landing along the Squirrel River. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September, 9, 1997, at 1048, the pilot reported the airplane touched down in a grassy area. The airplane was equipped with oversize tires inflated to about 12 PSI. An adhesive, applied between the main wheel rim and the tire, helps to prevent the tire from rotating independent of the wheel. The pilot indicated that during the landing roll, the right tire rotated away from the wheel rim. The tire deflated and began vibrating. The right main landing gear then collapsed, and the right wing struck the ground. The pilot did not return a pilot/operator report (NTSB report 6120.1/2). -