Cessna 177 Cardinal Carry-Thru Spar Inspection (AD 2023-02-17)
A visual and eddy current check of the carry-thru spar lower cap, required on every 177 variant.
AD 2023-02-17put the Cardinal under the same carry-thru spar inspection the FAA first required on the Cessna 210.
The trigger was the 2019 in-flight breakup of a T210M in Australia, traced to a fatigue crack that started at a corrosion pit in the spar's lower cap. The AD took effect on March 20, 2023. It covers the 177, 177A, 177B, 177RG, and F177RG, along with later 210 models.
What the inspection involves
- A visual inspection of the carry-thru spar lower cap with a 10X magnifier, looking for corrosion, cracks, and damage
- An eddy current inspection of the cap's kick area and any spot where corrosion was removed
- Corrosion removal within the AD's limits, then primer and a corrosion-inhibiting compound
If your Cardinal hasn't complied yet
The AD gave owners 200 hours or 12 months, whichever came first. That window has closed. Under 14 CFR 39.7, operating an airplane that doesn't meet an applicable AD is a violation. This matters most for Cardinals coming out of storage, changing hands, or missing a clear logbook entry.
The FAA calls the AD an interim action, so more rulemaking may follow.
What it costs
The FAA's estimates, at $85 an hour:
- Access and visual inspection: about 20 hours, $1,700
- Eddy current inspection: about $600, as a contracted service
- Total: about $2,300
- New carry-thru spar for a 177-series airplane, if one is needed: about $40,200
Who does the work
Your A&P handles access and the visual inspection. The eddy current step is specialized NDT work that most shops contract out. We connect you with an eddy current inspector who covers your airport.
Related inspections
Cessna 210 Carry-Thru Spar InspectionWing Spar Eddy Current InspectionWing Spar Corrosion Repair
This page summarizes AD 2023-02-17. Always work from the current AD text and your mechanic's judgment.
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