Summary
We propose to adopt a new airworthiness directive (AD) for Hamilton Standard Division model 6/5500/F and 24PF and Hamilton Sundstrand Corporation model 14RF, 14SF, 247F, and 568F series propellers. This proposed AD was prompted by the amount of corrosion detected during major inspections (MIs). This proposed AD would require incorporating inspections, based on a calendar time, into the propeller maintenance schedule. We are proposing this AD to prevent corrosion that could result in propeller failure and loss of airplane control.