AD 55-15-04

final rule

Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes

AD Number
55-15-04
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft propeller assembly
Problem area Propeller

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company DC-6 Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes
aircraft The Boeing Company DC-6A Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes
aircraft The Boeing Company DC-6B Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes

Unsafe Condition

Propeller feathering lines forward of the firewall may fail due to fire exposure, compromising the integrity of the propeller feathering system.

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

Required Actions

Replace existing propeller feathering lines forward of the firewall with fireproof/fire resistant hose assemblies (Aeroquip P/N 304004-10-17 1/2, Resistoflex SSFR-3800-10, or Aeroquip 309009-10S). Remove existing 304 sleeves from the feathering pump supply line and install Douglas P/N 3500614-1 fireproof cover. Alternative acceptable assemblies include Aeroquip 601000 with 304 full sleeves or Aeroquip 680-16S with 304 short sleeves.

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

Compliance Time

By first scheduled engine change after November 1, 1955, but not later than November 1, 1956.

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

Affected Aircraft

Douglas DC-6, DC-6A, DC-6B series airplanes below fuselage No. 487 equipped with Hamilton Standard propellers.

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

Federal Register Abstract

Propeller Feathering Lines

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_55-15-04.html
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AD Number:
55-15-04
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes
Subject:
Propeller Feathering Lines
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
The Boeing Company
Model:
DC-6 | DC-6A | DC-6B
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: 55-15-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   55-15-04

SUBJECT HEADING:   Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
55-15-04 DOUGLAS: Applies to all DC-6 Series Airplanes Below fuselage No. 487 Equipped With Hamilton Standard Propellers.

Compliance required by first scheduled engine change after November 1, 1955, but not later than November 1, 1956.

To increase the integrity of the propeller feathering system in the event of a powerplant fire, all existing propeller feathering lines located forward of the firewall must be replaced with lines and flexible hose assemblies which will meet current fireproof and fire resistant requirements.

(a) Replace the existing flexible hose portion of the feathering line between the union on the forward pipe assembly and the elbow on the inner ring with a new hose assembly Aeroquip P/N 304004-10-17 1/2. Douglas General Service Letter DC-6 No. 206 dated August 26, 1954, covers this subject. Resistoflex SSFR-3800-10 hose assembly and Aeroquip 309009-10S hose assembly are also considered acceptable for this application.

(b) The existing flexible hose assembly connecting to the governor is not affected by this directive.

(c) Remove the existing short 304 sleeves or flexible metal sleeve from the feathering pump supply line, Aeroquip P/N 304002-16D-12 3/8, and install a fireproof cover, Douglas P/N 3500614-1. Douglas General Service Letter DC-6 No. 206 dated August 26, 1954, covers this subject. Aeroquip 601000 hose assembly equipped with Aeroquip 304 full length protective sleeve or Aeroquip 680-16S hose assembly equipped with Aeroquip 304 short sleeves covering the end fittings are also considered acceptable for this application.


FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_55-15-04.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
55-15-04
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes
Subject:
Propeller Feathering Lines
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
The Boeing Company
Model:
DC-6 | DC-6A | DC-6B
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: 55-15-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   55-15-04

SUBJECT HEADING:   Airworthiness Directives; DOUGLAS All DC-6 Series Airplanes

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
55-15-04 DOUGLAS: Applies to all DC-6 Series Airplanes Below fuselage No. 487 Equipped With Hamilton Standard Propellers.

Compliance required by first scheduled engine change after November 1, 1955, but not later than November 1, 1956.

To increase the integrity of the propeller feathering system in the event of a powerplant fire, all existing propeller feathering lines located forward of the firewall must be replaced with lines and flexible hose assemblies which will meet current fireproof and fire resistant requirements.

(a) Replace the existing flexible hose portion of the feathering line between the union on the forward pipe assembly and the elbow on the inner ring with a new hose assembly Aeroquip P/N 304004-10-17 1/2. Douglas General Service Letter DC-6 No. 206 dated August 26, 1954, covers this subject. Resistoflex SSFR-3800-10 hose assembly and Aeroquip 309009-10S hose assembly are also considered acceptable for this application.

(b) The existing flexible hose assembly connecting to the governor is not affected by this directive.

(c) Remove the existing short 304 sleeves or flexible metal sleeve from the feathering pump supply line, Aeroquip P/N 304002-16D-12 3/8, and install a fireproof cover, Douglas P/N 3500614-1. Douglas General Service Letter DC-6 No. 206 dated August 26, 1954, covers this subject. Aeroquip 601000 hose assembly equipped with Aeroquip 304 full length protective sleeve or Aeroquip 680-16S hose assembly equipped with Aeroquip 304 short sleeves covering the end fittings are also considered acceptable for this application.


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.