Airworthiness Directive · Amendment 39-19050 · Turbine engine compressor section
General Electric Company Turboshaft Engines
This AD applies to General Electric Company (GE) CT7-8A and CT7-9B model turboshaft engines with a high-pressure compressor (HPC) impeller, part number 5123T51P02, and serial number, GLHTPH9G, GLHTPP7P, or GLHTPJHN, installed.
We are adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CT7-8A and CT7-9B model turboshaft engines. This AD was prompted by reports from the manufacturer that the high-pressure compressor (HPC) impeller installed on these engines may have suffered from material degradation during the manufacturing process. This AD requires removal of the affected HPC impellers. We are issuing this AD to address the unsafe condition on these products.
(1) For CT7-9B engines, remove the affected HPC impeller from service at the next engine shop visit after the effective date of this AD, or prior to accumulating 12,000 cycles since new, whichever is earlier.
(2) For CT7-8A engines, remove the affected HPC impeller from service at the next engine shop visit after the effective date of this AD, or prior to accumulating 1,500 engine hours after the effective date of this AD, whichever is earlier.
For the purpose of this AD, an “engine shop visit” is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine flanges.
