EASA SIB CE-11-40
Allied Ag Cat Productions, Inc. (formerly Grumman, Schweizer) G-164 series — Potential Cracking in the Rudder
Summary
The Special Airworthiness Information Bulletin SAIB: CE-11-40 informs owners, operators, and maintenance personnel of Allied Ag Cat Productions, Inc. G-164 series airplanes about potential cracking in the rudder main spar tube. This bulletin covers models G-164, G-164A, G-164B (including variants with 73” wing gap and turbocharged versions), G-164C, and G-164D under Type Certificate Data Sheet 1A16. The FAA does not consider this an unsafe condition requiring mandatory Airworthiness Directive action at this time.
What Changed
This bulletin introduces an informational advisory regarding the discovery of cracks in the rudder main spar tube above the upper hinge attach point on Allied Ag Cat G-164 series airplanes. It provides a recommended inspection procedure to detect rudder cracking, which is not detailed in the existing maintenance manual. The FAA and the type certificate holder recommend applying light lateral hand pressure to identify fabric deformation indicating possible cracks.
Why It Matters
This information is important for aviation professionals because undetected rudder cracks could compromise flight control integrity. Operators and maintenance personnel need to be aware of this potential issue to ensure thorough inspections beyond standard maintenance checks. Early detection helps prevent structural failure and maintains aircraft airworthiness and safety.
What To Do
Maintenance personnel should incorporate the recommended inspection procedure by applying light hand pressure laterally on the rudder while observing for fabric deformation or wrinkling. If any signs of deformation are found, the rudder must be considered non-airworthy until further visual or non-destructive inspections confirm no structural cracking or failure. No specific compliance deadline is provided, but inspections should be conducted during routine maintenance or when the rudder is recovered.
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