CESSNA 177 — Maintenance Manual

This service letter, SEL-57-09, addresses the mandatory inspection of the carry-thru spar for Cessna Model 177 aircraft. It outlines the potential for corrosion and cracks that can lead to structural failure, emphasizing the importance of compliance to ensure safety. The document provides detailed instructions for conducting a thorough inspection, including the use of specific materials and tools. It is crucial for aircraft owners and maintenance personnel to adhere to the guidelines to prevent undetected issues that could compromise aircraft integrity. Compliance is mandatory within 200 flight hours or the next annual inspection, whichever comes first, and the document serves as a critical resource for maintaining airworthiness.

• Mandatory inspection of carry-thru spar within 200 flight hours or next Annual Inspection.
• Applies to specific serial numbers of Cessna Model 177 and variants.
• Inspection includes detailed visual checks and possible eddy current testing for corrosion.
• Use of specified materials and tools is critical for compliance and safety.
• Results must be reported to Textron Aviation for record-keeping.