Summary
The FAA proposes to adopt a new airworthiness directive (AD) for GE CT7-9C and -9C3 turboprop engines with certain serial number (S/ N) gas generator turbine (GGT) shafts, part number (P/N) 6068T44P02, installed. This proposed AD would require inspecting the GGT shaft for nonconforming land balance-cuts, and if found, removing the shaft from service. This proposed AD results from reports of a manufacturing quality problem. We are proposing this AD to detect nonconforming GGT shaft land balance-cuts, which could result in the shaft failing before its published life limit, and which could result in an uncontained engine failure and damage to the airplane.