# Airworthiness Directives; General Electric Company CT7-5, -7, and -9 Series Turboprop Engines
> **Rule** · Final rule. · Published 2007-04-09 · Effective 2007-05-14 · 72 FR 17379
## Document
- **Document number:** E7-6446
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 72 FR 17379
- **Publication date:** 2007-04-09
- **Effective date:** 2007-05-14
- **FAA docket:** Docket No. FAA-2005-20944
## Abstract

The FAA is superseding an existing airworthiness directive (AD) for General Electric Company (GE) CT7-5A2, -5A3, -7A, -7A1, -9B, - 9B1, and -9B2, -9C, -9C3, -9D, and -9D2 turboprop engines, with certain part number (P/N) and serial number stage 2 turbine aft cooling plates installed. That AD currently requires a onetime eddy current inspection (ECI) of boltholes in certain P/N stage 2 turbine aft cooling plates. This AD expands the population of affected CT7 turboprop engine models, but reduces the number of cooling plates affected. It also requires a onetime ECI of boltholes in certain P/N stage 2 turbine aft cooling plates with specific serial numbers. This AD results from the manufacturer expanding the list of affected engine models and identifying the affected stage 2 turbine aft cooling plates by serial number. We are issuing this AD to prevent separation of the stage 2 turbine aft cooling plate, resulting in uncontained engine failure and damage to the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2007/04/09/E7-6446/airworthiness-directives-general-electric-company-ct7-5--7-and--9-series-turboprop-engines)
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