AD 48-09-02

final rule

Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft

AD Number
48-09-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company C54-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company C54A-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company C54B-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company C54D-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company C54E-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company C54G-DC Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
aircraft The Boeing Company DC-4 Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft

Unsafe Condition

Short circuits in the electrical distribution bus from nacelles one to four, which cannot be protected by circuit protective devices.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect the bus for 1/2-inch clearance from protuberances in nacelle areas, replace substandard brackets and clamps with approved Douglas standard quality and Adel or equivalent cushioned nongrounding type, inspect and replace No. 1/0 nacelle-to-bus feeder cables if chafing or mechanical deterioration is evident.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Inspection required by April 1, 1948, and thereafter at intervals not to exceed 400 hours (or at each routine check period for scheduled air carrier operators); inspection required not later than July 1, 1948, and thereafter at intervals not to exceed 8,000 hours; and determine compliance by June 1, 1948.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Douglas C-54 and DC-4 Aircraft, including models C54-DC, C54A-DC, C54B-DC, C54D-DC, C54E-DC, C54G-DC, and DC-4.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Electrical Distribution Bus

Applicability Source Text

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AD Final Rules - DRS_48-09-02.html
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AD Number:
48-09-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
Subject:
Electrical Distribution Bus
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: 48-09-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   48-09-02

SUBJECT HEADING:   Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft


ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
48-09-02 DOUGLAS: Applies to C-54 and DC-4 Aircraft.

To preclude the probability of short circuits occurring in the electrical distribution bus which runs from nacelles number one to four, and which is impracticable to protect by circuit protective devices, the following must be accomplished to assure that this bus will be in a fault-free condition.

I. Inspection required by April 1, 1948, and thereafter at intervals not to exceed 400 hours (or in the case of scheduled air carrier operators at each routine check period.)

Determine that at least 1/2-inch clearance is maintained between the bus and protuberances likely to "ground" the bus in the nacelle areas. Note particularly this clearance at the engine control pulleys and the pulley guide brackets.

II. Inspection required not later than July 1, 1948, and thereafter at intervals not to exceed 8,000 hours.

In those installations where the large No. 1/0 nacelle-to-bus feeder cables are run in metallic conduit, such cables must be pulled out for inspection. Replace by new cable ANA Spec. ANJC48a or Douglas DES SM-2001, where chafing or mechanical deterioration of the insulation is evident.

(NOTE: Oil-soaked insulation alone is not considered as sufficient cause to require the replacement of this cable.)

III. Not later than June 1, 1948.

Determine that the bus supporting brackets are of approved Douglas Aircraft Co. standard quality and that Adel or equivalent cushioned nongrounding type bus clamps are used for clamping the bus onto the brackets. Any substandard brackets and clamps must be replaced.

(Douglas Service Letter No. A214TS-1245/SRD-530 dated October 10, 1947, covers this same subject.)


FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_48-09-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
48-09-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft
Subject:
Electrical Distribution Bus
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: 48-09-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   48-09-02

SUBJECT HEADING:   Airworthiness Directives; DOUGLAS C-54 and DC-4 Aircraft


ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
48-09-02 DOUGLAS: Applies to C-54 and DC-4 Aircraft.

To preclude the probability of short circuits occurring in the electrical distribution bus which runs from nacelles number one to four, and which is impracticable to protect by circuit protective devices, the following must be accomplished to assure that this bus will be in a fault-free condition.

I. Inspection required by April 1, 1948, and thereafter at intervals not to exceed 400 hours (or in the case of scheduled air carrier operators at each routine check period.)

Determine that at least 1/2-inch clearance is maintained between the bus and protuberances likely to "ground" the bus in the nacelle areas. Note particularly this clearance at the engine control pulleys and the pulley guide brackets.

II. Inspection required not later than July 1, 1948, and thereafter at intervals not to exceed 8,000 hours.

In those installations where the large No. 1/0 nacelle-to-bus feeder cables are run in metallic conduit, such cables must be pulled out for inspection. Replace by new cable ANA Spec. ANJC48a or Douglas DES SM-2001, where chafing or mechanical deterioration of the insulation is evident.

(NOTE: Oil-soaked insulation alone is not considered as sufficient cause to require the replacement of this cable.)

III. Not later than June 1, 1948.

Determine that the bus supporting brackets are of approved Douglas Aircraft Co. standard quality and that Adel or equivalent cushioned nongrounding type bus clamps are used for clamping the bus onto the brackets. Any substandard brackets and clamps must be replaced.

(Douglas Service Letter No. A214TS-1245/SRD-530 dated October 10, 1947, covers this same subject.)


FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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