Rotorcraft Update: Emergency AD grounds Bell 407 fleet

 - May 9, 2008, 6:54 AM

Once again, an emergency AD (No. 2002-23-51) has mandated no further flight of the roughly 360 Bell 407 helicopters currently in service. The November 13 AD was prompted by two reported failures of the stud from a swashplate drivelink assembly. One or both swashplate drivelink cup washers may have been installed incorrectly. If not detected, this condition could limit the travel of the swashplate outer ring and lead to stud failure, failure of both swashplate drivelink studs and loss of control of the helicopter. The Bell 407 has been beset by a number of ground-order ADs, most of them concerned with tail-rotor control and blade-clearance issues.