Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Pratt & Whitney Canada Corp. (P&WC) PW150A turboprop engines. This proposed AD was prompted by a determination by the manufacturer that certain PW150A engine high-pressure (HP) centrifugal impellers may exhibit a material microstructure anomaly that has a potential to adversely affect the low cycle fatigue characteristics of the part. This proposed AD would require replacement of the affected HP centrifugal impellers. The FAA is proposing this AD to address the unsafe condition on these products.