AD 47-21-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 411 |
Unsafe Condition
Short circuits between the generator lower terminal and the fitting on the hydraulic pump inlet hose have been reported.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install a self-threading insulator No. 145-54053 (or equivalent) on the generator lower terminal stud.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than August 1, 1947
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Affected Aircraft
Sierra Hotel Aero, Inc. Navion (Army L-17A) serial numbers NAV-4-2 Through 411
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Generator Terminal Stud Insulator
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-21-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-21-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 411 Subject: Generator Terminal Stud Insulator Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-21-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-21-08 SUBJECT HEADING: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 411 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-21-08 NAVION: (Was Mandatory Note 7 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through 411. To be accomplished not later than August 1, 1947. Short circuits have been reported caused between the generator lower terminal and the fitting on the hydraulic pump inlet hose. To prevent such short circuits, install a self-threading insulator No. 145-54053 (or equivalent) on the generator lower terminal stud. (NAA Field Service Bulletin No. 18 covers this change.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_47-21-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-21-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 411 Subject: Generator Terminal Stud Insulator Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) 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: 47-21-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-21-08 SUBJECT HEADING: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 411 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-21-08 NAVION: (Was Mandatory Note 7 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through 411. To be accomplished not later than August 1, 1947. Short circuits have been reported caused between the generator lower terminal and the fitting on the hydraulic pump inlet hose. To prevent such short circuits, install a self-threading insulator No. 145-54053 (or equivalent) on the generator lower terminal stud. (NAA Field Service Bulletin No. 18 covers this change.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
Related Airworthiness Directives
2008-05-14 Recurring
final ruleAirworthiness Directives; Sierra Hotel Aero, Inc. Models Navion (L-17A), Navion A (L-17B), (L-17C), Navion B, Navion D, Navion E, Navion F, Navion G, and Navion H Airplanes
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