The National Transportation Safety Board has stated that a business jet may have experienced stability problems before severe turbulence caused the death of a passenger. The NTSB is investigating a reported “trim issue” which refers to an aircraft’s control surface adjustments for stability and levelness during flight. Last year, pilots of the same model of Bombardier aircraft were instructed by the Federal Aviation Administration to take special pre-flight measures after trim problems had been reported. The passenger jet was headed to Virginia before diverting to Connecticut’s Bradley International Airport. Turbulence is unstable air in the atmosphere and can cause injuries despite improvements to airline safety; however, deaths from turbulence are rare. The FAA directive prompted revised cockpit procedures and expanded pre-flight checks of pitch trim for pilots under certain circumstances. The Bombardier BD-100-1A10, better known as the Challenger 300 and 350, was involved in the incident.