Accident Details
According to the pilot's report, during the taxi for takeoff at McGrath, Alaska, the left oversized Tundra tire deflated. Subsequently, the left wing of the aircraft contacted the ground.
Previous Accident and Unauthorized Repairs
One week prior to this event, the same airplane had been involved in an accident at a rural mining airstrip, during which the main landing gear collapsed while landing. At that accident site, the pilot performed unauthorized repairs on the landing gear and wing lift struts. The pilot constructed a main gear leg from iron water pipe and attached boards to the lift struts using tape. Following these repairs, the pilot intended to fly the airplane to Palmer, Alaska for further maintenance. The flight included an interim stop at McGrath for fuel, but the pilot did not seek repairs from any aviation repair facility before attempting to depart from McGrath.
Expert Commentary
Discussions with individuals knowledgeable about Tundra tires indicated that proper landing gear geometry is crucial for safe operation. When landing gear geometry is incorrect, additional side loads can be placed on the tire. These side loads may cause the tire to rotate on its rim, which can slice the valve stem and allow the tire to deflate.