Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Saab Model SAAB SF340A and SAAB 340B series airplanes. This AD requires repetitive inspections for wear of the brushes and leads and for loose rivets of the direct current (DC) starter generator, and related investigative/corrective actions if necessary. This AD is prompted by reports of premature failures of the DC starter generator prior to scheduled overhaul. We are issuing this AD to prevent failure of the starter generator, which could cause a low voltage situation in flight and result in increased pilot workload and reduced redundancy of the electrical powered systems.