N1836U

On March 24, 1998, at 2008 mountain daylight time, a McDonnell Douglas DC-10-10, N1836U, operated by United Airlines as flight 1197, from Denver, Colorado, to Seattle, Washington, sustained minor damage during takeoff roll when a tire failed. None of the 299 persons aboard the aircraft were injured. The flight was operating under Title 14 CFR Part 121 and an IFR flight plan was filed. Visual meteorological conditions prevailed.

The investigation provided information that during takeoff roll the number 2 left main tire failed. Part of the tire was ingested into the number 1 engine and part went into the left main wheel well. The flight deck crew operated the number one engine at reduced power due to vibration, and the flight returned to Denver, landing at 1834, after dumping 8,400 pounds of fuel.

Following landing, the brakes froze due to overheating and the passengers were deplaned and taken to the terminal via bus. After the left main landing gear wheels were replaced, the aircraft was towed to a United Airlines hangar where repairs were made.

Postincident examination provided evidence of foreign object damage to the number one engine and two holes in the lower left wing skin above the left main landing gear wheel well.

At the request of the Safety Board Investigator-In-Charge, an engineering analysis on the failed tire was conducted by United Airlines Engineering, utilizing Michelin/Gooddrich Aircraft Tire Corporation's failure analysis laboratory. According to the attached failure analysis report, the tire failed as a result of elevated temperature and high levels of fatigue "probably" due to repeated retreading of the tire. As a precautionary measure, Michelin/Goodrich proposed that 50X20-20 DC-10 tires be limited to two retreads (R-2). United agreed and ceased to use tires which had more than the second retread. In addition, Michelin/Goodrich ceased to ship 50X20-20 tires which had more then the R-2 retread to its customer consignment points.