AD 88-20-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11 | Airworthiness Directives; MITSUBISHI HEAVY INDUSTRIES, LTD. (formerly Nihon Aeroplane Manufacturing Company (NAMC) Model YS-11/-11A Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-200 | Airworthiness Directives; MITSUBISHI HEAVY INDUSTRIES, LTD. (formerly Nihon Aeroplane Manufacturing Company (NAMC) Model YS-11/-11A Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-300 | Airworthiness Directives; MITSUBISHI HEAVY INDUSTRIES, LTD. (formerly Nihon Aeroplane Manufacturing Company (NAMC) Model YS-11/-11A Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-500 | Airworthiness Directives; MITSUBISHI HEAVY INDUSTRIES, LTD. (formerly Nihon Aeroplane Manufacturing Company (NAMC) Model YS-11/-11A Series Airplanes |
| aircraft | Mitsubishi Heavy Industries, Ltd. | YS-11A-600 | Airworthiness Directives; MITSUBISHI HEAVY INDUSTRIES, LTD. (formerly Nihon Aeroplane Manufacturing Company (NAMC) Model YS-11/-11A Series Airplanes |
Unsafe Condition
Failure of the vertical stabilizer front spar-to-fuselage fittings due to cracked lugs in Part Number 01-38101-11/-12 fittings.
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Required Actions
Within 600 hours time-in-service or 4 months after the effective date, visually inspect the vertical stabilizer front spar fuselage side fittings for cracked lugs per NAMC SB A53-71. Repeat inspections every 1,000 hours time-in-service. If cracks found, remove the fitting and perform inspections, corrosion treatment, and part replacement per NAMC SB 53-70 before further flight. If no cracks found, accomplish corrosion treatment and part replacement within 6,000 hours time-in-service or by January 1, 1990. Alternate compliance may be approved by the FAA.
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Compliance Time
Within 600 hours time-in-service after the effective date of this AD or within 4 months after the effective date of this AD, whichever occurs first
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Affected Aircraft
Mitsubishi Heavy Industries, Ltd. Model YS-11/-11A series airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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