AD 46-38-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Grumman American Aviation Corporation | G-21 | Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft |
| aircraft | Grumman American Aviation Corporation | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) | Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft |
Unsafe Condition
Raw fuel lodging in the vacuum system check valve, causing valve deterioration and possible fuel seeping.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Reroute vacuum system tubing in engine compartments, inspect flap system storage tank and flush if fuel is present, remove and inspect check valves for wear/deterioration, replace check valves if fuel is found in the storage tank.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
prior to November 1, 1946
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Grumman Model G-21 and G-21A Aircraft (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B)
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Vacuum System Tubing
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_46-38-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 46-38-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft Subject: Vacuum System Tubing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Grumman American Aviation Corporation Model: G-21 | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 46-38-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 46-38-01 SUBJECT HEADING: Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 46-38-01 GRUMMAN: (Was Mandatory Note 4 of AD-654-1.) Applies to G-21 and G- 21A Aircraft. Compliance required prior to November 1, 1946. Reroute to vacuum system tubing in the engine compartments to prevent raw fuel from lodging in the check valve, thus deteriorating the valve and possible seeping through. The flap system storage tank should be inspected and if fuel is found it should be thoroughly flushed. The check valves in the vacuum system are to be removed and inspected for wear and deterioration. Presence of fuel in the flap system storage tank is sufficient cause for the replacement of the check valves. (Grumman Service Bulletin No. 19 dated July 18, 1946, covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_46-38-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 46-38-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft Subject: Vacuum System Tubing Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Grumman American Aviation Corporation Model: G-21 | G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B) 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: 46-38-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 46-38-01 SUBJECT HEADING: Airworthiness Directives; Grumman Model G-21 and G- 21A Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 46-38-01 GRUMMAN: (Was Mandatory Note 4 of AD-654-1.) Applies to G-21 and G- 21A Aircraft. Compliance required prior to November 1, 1946. Reroute to vacuum system tubing in the engine compartments to prevent raw fuel from lodging in the check valve, thus deteriorating the valve and possible seeping through. The flap system storage tank should be inspected and if fuel is found it should be thoroughly flushed. The check valves in the vacuum system are to be removed and inspected for wear and deterioration. Presence of fuel in the flap system storage tank is sufficient cause for the replacement of the check valves. (Grumman Service Bulletin No. 19 dated July 18, 1946, covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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