AD 52-26-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and \\nSubsequent |
| aircraft | Sierra Hotel Aero, Inc. | Navion A (Army L-17B and L-17C) | Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and \\nSubsequent |
| aircraft | Sierra Hotel Aero, Inc. | Navion B | Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and \\nSubsequent |
Unsafe Condition
Cracks in the stabilizer spar web (gusset), root rib, and fuselage attaching fitting (P/N 143-31004-13) could lead to structural failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the stabilizer fuselage attachment area for cracks, focusing on the stabilizer spar web gusset outboard of the root rib and fuselage fitting. Replace fuselage fitting P/N 143-31004-13 if cracks are found. Repair root rib cracks per CAM No. 18 or replace the spar web gusset with a new part per Figure 2. Discontinue inspections after installing new gussets.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
As soon as practical, but not later than February 1, 1953, and at 100-hour intervals thereafter.
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Affected Aircraft
Sierra Hotel Aero, Inc. Navion models (Army L-17A, Navion A L-17B/C, Navion B), serial numbers NAV-4-2 and subsequent.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Stabilizer Spar Web
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_52-26-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 52-26-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and \nSubsequent Subject: Stabilizer Spar Web Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) | Navion A (Army L-17B and L-17C) | Navion B Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 52-26-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 52-26-01 SUBJECT HEADING: Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and Subsequent ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 52-26-01 NAVION: Applies to All Models, Serial Numbers NAV-4-2 and Subsequent. Compliance required as indicated. Inspect as soon as practical, but not later than February 1, 1953, and at 100-hour intervals thereafter the area in the vicinity of the stabilizer fuselage attachment for cracks. Particular attention should be given to the stabilizer spar web (gusset) immediately outboard of the root rib and the fuselage attaching fitting. If cracks are found in the fuselage fitting, P/N 143-31004-13, the entire part should be replaced. Cracks in the root rib may be repaired in accordance with CAM No. 18. Cracks in the spar web (gusset) require the replacement of the gusset with a new part made in accordance with Figure 2. AD 52-26-01 Periodic inspections of stabilizer spar web only may be discontinued after installation of new gussets. (Ryan Navion Field Service Bulletin No. 17 dated September 28, 1952, covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_52-26-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 52-26-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and \nSubsequent Subject: Stabilizer Spar Web Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) | Navion A (Army L-17B and L-17C) | Navion B Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 52-26-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 52-26-01 SUBJECT HEADING: Airworthiness Directives; Navion Applies to All Models, Serial Numbers NAV-4-2 and Subsequent ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 52-26-01 NAVION: Applies to All Models, Serial Numbers NAV-4-2 and Subsequent. Compliance required as indicated. Inspect as soon as practical, but not later than February 1, 1953, and at 100-hour intervals thereafter the area in the vicinity of the stabilizer fuselage attachment for cracks. Particular attention should be given to the stabilizer spar web (gusset) immediately outboard of the root rib and the fuselage attaching fitting. If cracks are found in the fuselage fitting, P/N 143-31004-13, the entire part should be replaced. Cracks in the root rib may be repaired in accordance with CAM No. 18. Cracks in the spar web (gusset) require the replacement of the gusset with a new part made in accordance with Figure 2. AD 52-26-01 Periodic inspections of stabilizer spar web only may be discontinued after installation of new gussets. (Ryan Navion Field Service Bulletin No. 17 dated September 28, 1952, covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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