AD 47-21-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sierra Hotel Aero, Inc. | Navion (Army L-17A) | Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251. |
Unsafe Condition
The original fuel filler scupper collects spilled gasoline due to lack of a drain line and has insufficient material thickness to prevent damage from the filler hose nozzle.
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Required Actions
Install a redesigned scupper with drain line per NAA Drawing 145-89010.
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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 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Fuel Scupper Drain Line
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-21-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-21-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 4...Show more Subject: Fuel Scupper Drain Line 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Sierra Hotel Aero, Inc. Model: Navion (Army L-17A) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-21-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-21-04 SUBJECT HEADING: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-21-04 NAVION: (Was Mandatory Note 3 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251. To be accomplished not later than August 1, 1947. The original fuel filler scupper will collect spilled gasoline since no drain line is provided. In addition, the thickness of material is insufficient to prevent damaging by the filler hose nozzle. To eliminate these conditions, a redesigned scupper with drain line is to be installed per NAA Drawing 145-89010. (NAA Field Service Bulletin No. 2 covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_47-21-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-21-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 4...Show more Subject: Fuel Scupper Drain Line 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: 47-21-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-21-04 SUBJECT HEADING: Airworthiness Directives; Navion Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251. ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-21-04 NAVION: (Was Mandatory Note 3 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251. To be accomplished not later than August 1, 1947. The original fuel filler scupper will collect spilled gasoline since no drain line is provided. In addition, the thickness of material is insufficient to prevent damaging by the filler hose nozzle. To eliminate these conditions, a redesigned scupper with drain line is to be installed per NAA Drawing 145-89010. (NAA Field Service Bulletin No. 2 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
Unsafe Condition: Leaking or improperly operating fuel selector valves may disrupt fuel flow to the engine, leading to engine power loss.
68-20-06
final ruleAirworthiness Directives; Navion Models Navion through Navion H Airplanes
Unsafe Condition: Failure of the Rudder Horn, P/N 145-24401, due to horizontal cracks or corrosion in the edge, which may appear as delaminations or swelling under the paint.
62-03-03
final ruleAirworthiness Directives; Navion Models Navion, Navion A, Navion B, Navion D, Navion E, Navion F, and Navion G Aircraft
Unsafe Condition: The landing gear selector valve end fitting P/N 145-58145-3 (heat treated and non-heat treated) has a service history of failure during attempts to extend the gear.
47-31-03
final ruleAirworthiness Directives; Navion Serial Numbers NAV-4-2 Through NAV-4-1010 Which Incorporate Koehler Model 2250 Fuel Strainers
Unsafe Condition: Loss of fuel pressure due to air leakage into the fuel system through the CCA-1550-1/8 drain cock on the Koehler Model 2250 fuel strainer.
