AD Issued on Global Express PCU Bolt
The FAA has issued an airworthiness directive (AD 2009-15-03) for Bombardier Global Express BD-700-1A10s and BD-700-1A11s. According to the AD, a bolt that connects the power control unit (PCU) to the elevator surface was found fractured in the assembly during a scheduled maintenance inspection. Further inspection of the assembly revealed that the bearing on the PCU rod end had seized, which resulted in damage to the attachment fitting bushing and the subsequent fracture of the bolt. Inspection of other in-service aircraft revealed two more seized PCU attachment joints. Failure of the bolts in both PCUs on one side could result in disconnection of the elevator control surface, which would lead to flutter and consequent loss of the aircraft. The AD becomes effective Aug. 19, 2009. The required actions include inspections for damage and seizure (including signs of seizure) of the PCU attachment joints, an inspection for damage (including wear damage, fretting, corrosion, galling, scoring and fretting wear, as well as parts that do not meet inspection requirements) of the PCU attachment joint components and applicable corrective actions.