AD 76-07-07

final rule

Airworthiness Directives; CESSNA Model 421C Airplanes

AD Number
76-07-07
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Cessna Aircraft Company 421C Airworthiness Directives; CESSNA Model 421C Airplanes

Unsafe Condition

Leakage of fuel and an engine nacelle fire due to deterioration of the P/N S1129-03-0304 hose assembly fire sleeve and potential hardening, cracks, or seepage in the hose when routed too close to exhaust system surfaces.

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

Required Actions

Inspect the P/N S1129-03-0304 hose assembly's fire sleeve for whitening or deterioration. If found, inspect the hose for hardening, cracks, or seepage and replace if necessary, maintaining at least four inches from exhaust surfaces. Install a new fire sleeve or reposition the existing one. Within 25 hours' time in service after the effective date, replace the hose assembly with Cessna P/N 5100109-56 steel line as per Service Kit SK421-69. Paragraph A is no longer applicable after completing Paragraph B.

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

Compliance Time

Prior to the next and each subsequent flight for Paragraph A; within 25 hours' time in service after the effective date for Paragraph B.

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

Affected Aircraft

Cessna Model 421C (Serial Numbers 421C0003 thru 421C0052 except 421C0008, 421C0017, 421C0019, 421C0026, 421C0039, 421C0045, 421C0046, and 421C0048)

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

Federal Register Abstract

Fuel Leakage

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_76-07-07.html
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AD Number:
76-07-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; CESSNA Model 421C Airplanes
Subject:
Fuel Leakage
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/12/1976
Make:
Cessna Aircraft Company
Model:
421C
Product Type:
Aircraft
Product Subtype:
Small 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Superseded AD: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Superseded By: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: 76-07-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2568

AD NUMBER:   76-07-07

SUBJECT HEADING:   Airworthiness Directives; CESSNA Model 421C Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective April 12, 1976.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
76-07-07 CESSNA: Amendment 39-2568. Applies to Model 421C (Serial Numbers 421C0003 thru 421C0052 (except 421C0008, 421C0017, 421C0019, 421C0026, 421C0039, 421C0045, 421C0046 and 421C0048) airplanes.

Compliance: Required as indicated, unless already accomplished.

To prevent leakage of fuel and an engine nacelle fire:

A) Prior to the next and each subsequent flight, accomplish the following:

1. Visually inspect the P/N S1129-03-0304 hose assembly located in the right hand engine nacelle (see Item No. 63 in the 1976 Cessna Model 421C Parts Catalog, Pages 7-10, Fig. 1) in the area where this hose assembly routes under the exhaust manifold near the waste gate "Y".

2. Should whitening or general deterioration of the fire sleeve around the hose be noted, remove the sleeve and visually inspect the hose for hardening, cracks, seepage, etc. If any of these conditions are noted, replace this hose with a new hose routed so that a minimum of four inches between any exhaust system surface and the hose is maintained. If the hose is satisfactory, install a new fire sleeve or reinstall the existing fire sleeve so that the whitened or deteriorated area of the sleeve is not in the original location on the hose. Except for those aircraft utilized in air carrier service, the inspection of the fire sleeve for whitening or deterioration may be accomplished by a holder of a pilot's certificate issued under Part 61 of the Federal Aviation Regulations on any aircraft owned or operated by him. If the whitened or deteriorated condition is noted, the inspection of the hose and the correction of any unsatisfactory conditions found must be accomplished by a certificated powerplant mechanic.

3. An equivalent hose assembly may be field fabricated and installed if a factory hose is unavailable.

B) Within 25 hours' time in service after the effective date of this AD, replace the original P/N S1129-3-0304 hose assembly or any hose assembly installed per the above, with Cessna P/N 5100109-56 steel line as specified in Cessna Service Kit SK421-69.

C) When Paragraph B has been accomplished, Paragraph A is no longer applicable.

D) Any alternate means of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

This amendment becomes effective April 12, 1976, to all persons except those to whom it was made effective earlier by air mail letter issued March 5, 1976.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_76-07-07.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
76-07-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; CESSNA Model 421C Airplanes
Subject:
Fuel Leakage
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/12/1976
Make:
Cessna Aircraft Company
Model:
421C
Product Type:
Aircraft
Product Subtype:
Small 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: 76-07-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2568

AD NUMBER:   76-07-07

SUBJECT HEADING:   Airworthiness Directives; CESSNA Model 421C Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective April 12, 1976.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
76-07-07 CESSNA: Amendment 39-2568. Applies to Model 421C (Serial Numbers 421C0003 thru 421C0052 (except 421C0008, 421C0017, 421C0019, 421C0026, 421C0039, 421C0045, 421C0046 and 421C0048) airplanes.

Compliance: Required as indicated, unless already accomplished.

To prevent leakage of fuel and an engine nacelle fire:

A) Prior to the next and each subsequent flight, accomplish the following:

1. Visually inspect the P/N S1129-03-0304 hose assembly located in the right hand engine nacelle (see Item No. 63 in the 1976 Cessna Model 421C Parts Catalog, Pages 7-10, Fig. 1) in the area where this hose assembly routes under the exhaust manifold near the waste gate "Y".

2. Should whitening or general deterioration of the fire sleeve around the hose be noted, remove the sleeve and visually inspect the hose for hardening, cracks, seepage, etc. If any of these conditions are noted, replace this hose with a new hose routed so that a minimum of four inches between any exhaust system surface and the hose is maintained. If the hose is satisfactory, install a new fire sleeve or reinstall the existing fire sleeve so that the whitened or deteriorated area of the sleeve is not in the original location on the hose. Except for those aircraft utilized in air carrier service, the inspection of the fire sleeve for whitening or deterioration may be accomplished by a holder of a pilot's certificate issued under Part 61 of the Federal Aviation Regulations on any aircraft owned or operated by him. If the whitened or deteriorated condition is noted, the inspection of the hose and the correction of any unsatisfactory conditions found must be accomplished by a certificated powerplant mechanic.

3. An equivalent hose assembly may be field fabricated and installed if a factory hose is unavailable.

B) Within 25 hours' time in service after the effective date of this AD, replace the original P/N S1129-3-0304 hose assembly or any hose assembly installed per the above, with Cessna P/N 5100109-56 steel line as specified in Cessna Service Kit SK421-69.

C) When Paragraph B has been accomplished, Paragraph A is no longer applicable.

D) Any alternate means of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

This amendment becomes effective April 12, 1976, to all persons except those to whom it was made effective earlier by air mail letter issued March 5, 1976.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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