AD 47-10-30
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 49-46 | LOCKHEED Model 49 |
Unsafe Condition
Fuel tank surge box flapper valves (LAC P/N 285750) may fail, leading to potential fuel leakage or improper fuel distribution.
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Required Actions
Replace fuel tank surge box flapper valves LAC P/N 285750 with new type valve LAC P/N 285750-600. Compliance must follow Lockheed Service Instructions 49/SI-15 (revised August 10, 1946) or 49/SI-15A (revised August 3, 1946).
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Compliance Time
prior to April 1, 1947
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Affected Aircraft
Lockheed Aircraft Corporation Model 49-46, serial numbers 2047 up to and including 2075, and serials prior to 2047 with 68092 surge box flapper valves replaced by 285750 valves per Lockheed SI-15 dated June 18, 1946.
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Federal Register Abstract
Fuel Tank Surge Box Flapper Valves
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-10-30.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-10-30 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 49 Subject: Fuel Tank Surge Box Flapper Valves Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Lockheed Aircraft Corporation Model: 49-46 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-10-30 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-10-30 SUBJECT HEADING: LOCKHEED Model 49 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-10-30 LOCKHEED: (Was Mandatory Note 33 of AD-763-3.) Applies to Model 49 Serials 2047 Up to and Including 2075 and to Serials Prior to 2047 Which Have Had 68092 Surge Box Flapper Valves Replaced by 285750 Valves in Accordance With Lockheed SI-15, Dated June 18, 1946. Compliance required prior to April 1, 1947. Replace fuel tank surge box flapper valves, LAC P/N 285750, with new type valve, LAC P/N 285750-600. (LAC Service Instructions 49/SI-15, revised August 10, 1946, and 49/SI-15A, revised August 3, 1946, or subsequent, cover this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_47-10-30.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-10-30 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 49 Subject: Fuel Tank Surge Box Flapper Valves Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Lockheed Aircraft Corporation Model: 49-46 Product Type: Aircraft Product Subtype: Large 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: 47-10-30 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-10-30 SUBJECT HEADING: LOCKHEED Model 49 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-10-30 LOCKHEED: (Was Mandatory Note 33 of AD-763-3.) Applies to Model 49 Serials 2047 Up to and Including 2075 and to Serials Prior to 2047 Which Have Had 68092 Surge Box Flapper Valves Replaced by 285750 Valves in Accordance With Lockheed SI-15, Dated June 18, 1946. Compliance required prior to April 1, 1947. Replace fuel tank surge box flapper valves, LAC P/N 285750, with new type valve, LAC P/N 285750-600. (LAC Service Instructions 49/SI-15, revised August 10, 1946, and 49/SI-15A, revised August 3, 1946, or subsequent, cover 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.
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