Engine - Main Propeller Shaft - Inspection
- Published
- Effective
- Deadline
- Replaces
- 2018-03-13
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected GE CT7 engines must perform initial and repetitive visual, fluorescent penetrant, and ultrasonic inspections of the main propeller shaft according to specified compliance times. If inspection results indicate, the main propeller shaft must be replaced. As an optional terminating action, operators may revise the airworthiness limitations section of their maintenance manuals and approved maintenance or inspection programs to incorporate new tasks and reduced inspection intervals. Compliance with this AD is mandatory by December 11, 2023.
Summary
Airworthiness Directive 2023-21-07 is a final rule issued by the Federal Aviation Administration (FAA) addressing certain General Electric Company Model CT7 series engines, including CT7-5A2, CT7-5A3, CT7-7A, CT7-7A1, CT7-9B, CT7-9B1, CT7-9B2, CT7-9C, and CT7-9C3. This directive mandates inspections of the main propeller shaft to prevent in-flight failures that could result in loss of the propeller and engine thrust control. It applies to engines installed on U.S. registered aircraft and includes visual, fluorescent penetrant, and ultrasonic inspections.
What changed
This AD supersedes the previous AD 2018-03-13 by expanding inspection requirements to include ultrasonic inspections in addition to visual and fluorescent penetrant inspections. It also corrects engine model applicability and inspection thresholds based on comments from GE Aerospace. The directive introduces an optional terminating action involving revisions to the airworthiness limitations section of maintenance manuals and programs.
Why it matters
This directive is critical for aviation professionals as it addresses a serious unsafe condition involving potential in-flight failure of the main propeller shaft, which could lead to catastrophic loss of the propeller and engine control. Operators and maintenance organizations must comply to ensure continued airworthiness and safety of affected aircraft. The updated inspection methods and optional terminating actions provide clearer guidance and potentially reduce inspection frequency when incorporated into maintenance programs.
More for General Electric CT7-5
All 3Get the next one by email
New ADs and bulletins for General Electric CT7-5, Electric CT7-7 and Electric CT7-9, summarized like this page, every Monday.