Transportation safety board beginning four days of hearings . The NTSB is investigating the crash that killed a passenger and injured more than 100 others on July 6 in Schoharie, New York. Nine air ambulance crashes killed 35 people during one-year period . Board 's 2006 safety recommendations not fully implemented , it says .
Transportation safety board beginning four days of hearings . Board examines reported `` drastic increase '' in accidents and deaths . Nine air ambulance crashes killed 35 people during one-year period . Board 's 2006 safety recommendations not fully implemented , it says .