AD 47-10-19
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 49-46 | LOCKHEED Model 49 |
Unsafe Condition
The cabin heater fuel solenoid valve and fuel pump bypass line may be improperly located or routed, leading to potential fuel leakage or electrical short circuits. Additionally, the absence of heat protective shields in nacelle zone 2, improper mounting hardware in nacelle junction boxes, and lack of drain holes in spinner fairings may cause overheating, component failure, or moisture ingress.
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Required Actions
Relocate and waterproof the cabin heater fuel solenoid valve, replace and reroute the fuel pump bypass line, install heat protective shields in nacelle zone 2, replace mounting nuts and screws with AN 366 and NAS 221 hardware, and drill 1/4-inch drain holes in spinner fairing lower panels.
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Compliance Time
not later than 100 hours of operation after June 10, 1947
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Affected Aircraft
Lockheed Aircraft Corporation Model 49 serials up to and including 2088, except as noted. Specific requirements for serials up to 2082 for heat shields and all applicable serials for other modifications.
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Federal Register Abstract
Cabin Heater Fuel Solenoid Valve
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-10-19.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-10-19 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 49 Subject: Cabin Heater Fuel Solenoid Valve 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Make: Lockheed Aircraft Corporation Model: 49-46 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-10-19 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-10-19 SUBJECT HEADING: LOCKHEED Model 49 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-10-19 LOCKHEED: (Was Mandatory Note 21 of AD-763-3.) Applies to All Model 49 Serials Up to and Including 2088, Except as Noted. Compliance required not later than 100 hours of operation after June 10, 1947. (a) In each cabin heater installation, relocate and waterproof the fuel solenoid valve and replace and reroute the fuel pump bypass line. (LAC Service Bulletin 49/SB-73 covers this same subject.) (b) In zone 2 of each nacelle, install heat protective shield between propeller feathering line and cowl diaphragm. Applies to all serials up to and including 2082. (LAC Service Bulletin 49/SB-150 covers this same subject.) (c) In each outboard nacelle main junction box, replace existing mounting nuts (tinnerman) and PK screws with AN 366 nuts and NAS 221 screws. (LAC Service Bulletin 49/SB-152 covers this same subject.) (d) Drill one 1/4-inch drain hole on lower center line of spinner fairing lower panel assembly for each engine. (LAC Service Instruction 49/SI-95 covers this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_47-10-19.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-10-19 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LOCKHEED Model 49 Subject: Cabin Heater Fuel Solenoid Valve 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: 47-10-19 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-10-19 SUBJECT HEADING: LOCKHEED Model 49 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-10-19 LOCKHEED: (Was Mandatory Note 21 of AD-763-3.) Applies to All Model 49 Serials Up to and Including 2088, Except as Noted. Compliance required not later than 100 hours of operation after June 10, 1947. (a) In each cabin heater installation, relocate and waterproof the fuel solenoid valve and replace and reroute the fuel pump bypass line. (LAC Service Bulletin 49/SB-73 covers this same subject.) (b) In zone 2 of each nacelle, install heat protective shield between propeller feathering line and cowl diaphragm. Applies to all serials up to and including 2082. (LAC Service Bulletin 49/SB-150 covers this same subject.) (c) In each outboard nacelle main junction box, replace existing mounting nuts (tinnerman) and PK screws with AN 366 nuts and NAS 221 screws. (LAC Service Bulletin 49/SB-152 covers this same subject.) (d) Drill one 1/4-inch drain hole on lower center line of spinner fairing lower panel assembly for each engine. (LAC Service Instruction 49/SI-95 covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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