Summary
The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) JT15D-1, -1A, and -1B turbofan engines with certain impellers part number (P/N) 3020365. This proposed AD would require a one-time borescope inspection of the rear face of certain impellers for evidence of a machined groove or step, and repair or replacement of the impeller if a groove or step is found. This proposed AD is prompted by three reports of uncontained failure of the impeller. We are proposing this AD to prevent uncontained failure of the impeller and possible damage to the airplane.