AD 55-15-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| 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.
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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.
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Compliance Time
By first scheduled engine change after November 1, 1955, but not later than November 1, 1956.
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Affected Aircraft
Douglas DC-6, DC-6A, DC-6B series airplanes below fuselage No. 487 equipped with Hamilton Standard propellers.
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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 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The Boeing Company Model: DC-6 | DC-6A | DC-6B Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 55-15-04 CITATION: This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:
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
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