The National Transportation Safety Board will wrap up its public testimony on Friday about the fatal midair crash between an Army helicopter and a commercial jet earlier this year

Long-standing concerns about military helicopters flying in crowded airspace and worries over short staffing among federal aviation workers emerged Thursday as key factors in investigators' inquiry into the fatal midair crash between an Army helicopter and a commercial airliner earlier this year.

Investigators have found that a helicopter involved in a deadly crash with a passenger plane over Washington was flying above its height limit.