AD 47-31-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; NAVION All Serials Up to and Including Number NAV-4-947. |
Unsafe Condition
Nose gear hydraulic actuating cylinder line failures due to inflexibility.
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Required Actions
Replace the present lines with longer lines incorporating a 'U' bend and reinstall the cylinders with the lines leading aft.
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Compliance Time
not later than October 1, 1947
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Affected Aircraft
NAVION All Serials up to and including Number NAV-4-947
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Federal Register Abstract
Nose Gear Hydraulic Actuating Cylinder Lines
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-31-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-31-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; NAVION All Serials Up to and Including Number NAV-4-947. Subject: Nose Gear Hydraulic Actuating Cylinder Lines 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Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-31-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-31-01 SUBJECT HEADING: Airworthiness Directives; NAVION All Serials Up to and Including Number NAV-4-947. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-31-01 NAVION: (Was Mandatory Note 10 of AD-782-3.) Applies to All Serials Up to and Including Number NAV-4-947. To be accomplished not later than October 1, 1947. To reduce the possibility of nose gear hydraulic actuating cylinder line failures due to inflexibility, the cylinders must be removed and reinstalled with the lines therefrom leading aft. Each of the present lines must be replaced with a longer line incorporating a "U" bend. (North American Field Service Bulletin No. 28 covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_47-31-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-31-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; NAVION All Serials Up to and Including Number NAV-4-947. Subject: Nose Gear Hydraulic Actuating Cylinder Lines 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: 47-31-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-31-01 SUBJECT HEADING: Airworthiness Directives; NAVION All Serials Up to and Including Number NAV-4-947. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-31-01 NAVION: (Was Mandatory Note 10 of AD-782-3.) Applies to All Serials Up to and Including Number NAV-4-947. To be accomplished not later than October 1, 1947. To reduce the possibility of nose gear hydraulic actuating cylinder line failures due to inflexibility, the cylinders must be removed and reinstalled with the lines therefrom leading aft. Each of the present lines must be replaced with a longer line incorporating a "U" bend. (North American Field Service Bulletin No. 28 covers this same subject.) 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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