An August 15 emergency AD requires operators or owners of U.S.-registered Agusta AB139 helicopters to conduct an initial visual inspection before further flight, followed by inspections every 25 hours, looking for cracks on the tailpipe. The FAA said the directive (AD 2007-17-51) was prompted by several reports of tailpipe cracks and the issuance of an emergency AD by the European Aviation Safety Agency. “The reason for the [tailpipe cracking] has not been determined and is still under investigation,” the agency said.