On May 27, 2008, at about 10:00 AM central daylight time, American Eagle flight 3646, an Embraer 140, inadvertently flew through turbulent air. The seat belt sign was off at the time and an unbelted passenger received a serious injury. The flight had departed Springfield, MO (SGF), and subsequently landed uneventfully at Dallas-Fort Worth International Airport (DFW), its planned destination. According to the flight crew, the flight was carried out in smooth air for most of the way to Dallas. When the flight reached a point about 40 nm west of Bowie VOR, at 17,000 feet altitude, and as the airplane overflew a small cloud, the airplane was abruptly jolted by turbulence. The autopilot disconnected and was immediately reactivated by the flight crew. During the turbulence encounter, an elderly female passenger fell to the floor near the lavatory and suffered a broken ankle.