Aviation accident WPR17LA042

The decision of the maintenance facility mechanic to conduct maintenance without reference to the applicable manufacturer’s guidance, which resulted in the improper reassembly and subsequent failure of the engine compressor bleed valve, which in turn prevented the engine from responding to further power demand at a critical phase of flight. Contributing to the accident was the failure of the maintenance facility’s director of maintenance to ensure that the overhaul was conducted properly and that the required post-maintenance test procedures were accomplished.