EASA SIB CE-13-27R1
Airplanes with Cable-driven Flight Controls - Frayed Flap Extend Cables
Summary
The Special Airworthiness Information Bulletin (SAIB) CE-13-27R1 addresses the issue of frayed flap extend cables in airplanes with cable-driven flight controls, specifically including numerous Textron Aviation, Inc. (formerly Cessna) models such as the 310, 320, 335, 336, 337, 340, 401, 402, 411, 414, 421, and 425 series. This bulletin serves as an informational reminder to operators and maintenance personnel about the importance of thorough inspections of flight control cables to prevent failures. It does not impose mandatory requirements but highlights safety concerns related to cable wear and inspection challenges.
What Changed
SAIB CE-13-27R1 revises the original bulletin to include additional Textron Aviation airplane models with similar cable-driven flight control characteristics. It emphasizes the need for careful inspection around pulleys where fraying commonly occurs and clarifies that the issue is not currently considered an unsafe condition warranting an airworthiness directive under 14 CFR part 39.
Why It Matters
This bulletin is important for aviation professionals because frayed or failed flap extend cables can lead to sudden flap retraction and loss of control, as demonstrated by a recent incident involving a Textron Aviation airplane. Proper inspection and maintenance of these cables are critical to ensuring flight safety and preventing in-flight control issues. Operators and maintenance teams must be vigilant in detecting wear that may not be visible without detailed inspection techniques.
What To Do
Operators should follow existing maintenance manual inspection intervals, typically visual inspections every 200 flight hours or 12 months and expanded inspections every 1,600 hours, adjusting as specified for their aircraft model. Maintenance personnel should cycle flight controls fully during inspections to expose all cable sections and may need to remove cables for thorough examination. Reviewing FAA Advisory Circular AC 43.13-1B, Chapter 7, paragraph 7-149 on cable system inspection is also recommended.