AD 48-12-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | C54A-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | C54B-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | C54D-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | C54E-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | C54G-DC | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
| aircraft | The Boeing Company | DC-4 | Airworthiness Directives; DOUGLAS C54-DC and DC-4 |
Unsafe Condition
Heater fires in the nose and cabin heater installations pose a fire hazard due to lack of isolation between the heater compartment and adjacent fuselage spaces, non-hermetic heater control components, and inadequate protection of fuel line fittings.
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Required Actions
Install a steel firewall at Station 260 from ceiling level to top of bulkhead, replace wood panels under heaters with metal panels, install airtight steel containers for heater control components, replace fuel supply pumps with a single electric-driven pump attached to No. 2 main fuel tank, provide shrouds around heater fuel line fittings, and install a fire detector and extinguisher system for nose and cabin heaters.
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Compliance Time
not later than the date established in accordance with the provisions of Special Civil Air Regulation Serial Number SR-329, or any subsequent regulation affecting this compliance date
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Affected Aircraft
The Boeing Company C54-DC and DC-4 models with serial numbers 42904 Through 42943, 42948 Through 42952, 42982 Through 42996, 43065 Through 43068, 43071, 43072, 43093, 43094, and 43102.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Nose And Cabin Heater Rework
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_48-12-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-12-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS C54-DC and DC-4 Subject: Nose And Cabin Heater Rework Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | C54A-DC | C54B-DC | C54D-DC | C54E-DC | C54G-DC | DC-4 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: 48-12-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-12-02 SUBJECT HEADING: Airworthiness Directives; DOUGLAS C54-DC and DC-4 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-12-02 DOUGLAS: Applies to All C54-DC Serial and the Following DC-4 Airplanes: 42904 Through 42943, 42948 Through 42952, 42982 Through 42996, 43065 Through 43068, 43071, 43072, 43093, 43094, and 43102. To be accomplished not later than the date established in accordance with the provisions of Special Civil Air Regulation Serial Number SR-329, or any subsequent regulation affecting this compliance date. As a result of investigation of heater fires, the following changes are to be accomplished in the nose and cabin heater installation: 1. Install steel firewall at Station 260 (cabin forward bulkhead) from ceiling level to top of bulkhead to provide isolation between heater compartment and the space between cabin ceiling and top of fuselage. Also, replace present wood panels under heaters with metal panels. (Douglas Service Bulletin DC-4 No. 47 covers this same subject.) 2. (a) Install all heater control components in airtight steel containers. (b) Replace present heater fuel supply pumps with a single electric driven pump attached to No. 2 main fuel tank. (c) Provide shrouds around all heater fuel line fittings in fuselage. (d) Install a fire detector and extinguisher system for the nose heater and cabin heaters. (Douglas Service Bulletins DC-4 Nos. 64 and 64 addendum cover this same subject.) In some cases, operators have obtained approval from FAA Regional Offices for systems which differ in arrangement and detail from the above provisions. Designs which have been separately approved in this manner are considered to meet the intent of this Note. This supersedes AD 46-39-02. FOOTER:
Document Text
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AD Final Rules - DRS_48-12-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-12-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS C54-DC and DC-4 Subject: Nose And Cabin Heater Rework Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | C54A-DC | C54B-DC | C54D-DC | C54E-DC | C54G-DC | DC-4 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: 48-12-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-12-02 SUBJECT HEADING: Airworthiness Directives; DOUGLAS C54-DC and DC-4 ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-12-02 DOUGLAS: Applies to All C54-DC Serial and the Following DC-4 Airplanes: 42904 Through 42943, 42948 Through 42952, 42982 Through 42996, 43065 Through 43068, 43071, 43072, 43093, 43094, and 43102. To be accomplished not later than the date established in accordance with the provisions of Special Civil Air Regulation Serial Number SR-329, or any subsequent regulation affecting this compliance date. As a result of investigation of heater fires, the following changes are to be accomplished in the nose and cabin heater installation: 1. Install steel firewall at Station 260 (cabin forward bulkhead) from ceiling level to top of bulkhead to provide isolation between heater compartment and the space between cabin ceiling and top of fuselage. Also, replace present wood panels under heaters with metal panels. (Douglas Service Bulletin DC-4 No. 47 covers this same subject.) 2. (a) Install all heater control components in airtight steel containers. (b) Replace present heater fuel supply pumps with a single electric driven pump attached to No. 2 main fuel tank. (c) Provide shrouds around all heater fuel line fittings in fuselage. (d) Install a fire detector and extinguisher system for the nose heater and cabin heaters. (Douglas Service Bulletins DC-4 Nos. 64 and 64 addendum cover this same subject.) In some cases, operators have obtained approval from FAA Regional Offices for systems which differ in arrangement and detail from the above provisions. Designs which have been separately approved in this manner are considered to meet the intent of this Note. This supersedes AD 46-39-02. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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