United Airlines series of mishaps: four incidents in one week. A Boeing off the runway, a hydraulic problem, a broken engine, a wheel coming off the landing gear - all within a week.
The incidents are currently being investigated. The first known United incident from the breakdown week occurred last Monday. Flames erupted from the engine of one of the airline's Boeing 737-900s just 15 minutes after takeoff. The plane with 249 people on board was able to make an emergency landing safely.