AD 72-11-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 411 | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 411A | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421 | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421A | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421B | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421C | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
Unsafe Condition
Auxiliary fuel cell leakage could result in possible fire and explosion hazards from fuel vapor ignition.
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Required Actions
Visually inspect the lower wing surfaces near auxiliary fuel cells for stains/leakage. Replace leaking cells with improved cells per Cessna Service Letter ME72-8. For Model 411 (411-0001-0200), daily inspections until January 1, 1973, then mandatory replacement. For Model 411 (411-0201-0300) and Model 421 (421-0001-421B0048), inspections every 100 flight hours until improved cells are installed.
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Compliance Time
Within 10 hours' time in service after the effective date of this AD, and thereafter as specified (daily or every 100 flight hours).
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Affected Aircraft
Cessna Model 411 (Serial Numbers 411-0001 thru 411-0300) and Model 421 (Serial Numbers 421-0001 thru 421B0048) airplanes.
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Federal Register Abstract
Auxiliary Fuel Cell Leaks
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_72-11-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 72-11-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes Subject: Auxiliary Fuel Cell Leaks Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/02/1972 Make: Cessna Aircraft Company Model: 411 | 411A | 421 | 421A | 421B | 421C Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 72-11-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1454 AD NUMBER: 72-11-05 SUBJECT HEADING: Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes ACTION: SUMMARY: DATES: Effective June 2, 1972. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 72-11-05 CESSNA: Amdt. 39-1454. Applies to Models 411 and 421 series airplanes. Compliance: Required as indicated, unless already accomplished. In order to detect auxiliary fuel cell leakage that could result in possible fire and explosion hazards from fuel vapor ignition, accomplish the following: A) On Model 411 (Serial Numbers 411-0001 thru 411-0200) airplanes: 1) Within 10 hours' time in service after the effective date of this AD, and thereafter prior to the first flight of each day, visually inspect the lower surface of the wings in the area of the auxiliary fuel cells for fuel stains and leakage. If auxiliary fuel cell leakage is observed, prior to further flight, replace the auxiliary fuel cells with improved auxiliary fuel cells in accordance with Cessna Service Letter ME72-8, dated April 21, 1972, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. 2) The repetitive inspections required prior to the first flight of each day may be performed by the pilot, including pilots of aircraft engaged in air taxi operations. A chronological listing of compliance with this AD must be made in the airplane's permanent maintenance log in accordance with FAR 91.173. 3) On or before January 1, 1973, replace all auxiliary fuel cells with the improved auxiliary fuel cells specified in Cessna Service Letter ME72-8, dated April 21, 1972. 4) The repetitive inspections required in Paragraph A(1) may be discontinued when the improved auxiliary fuel cells are installed. B) On Model 411 (Serial Numbers 411-0201 thru 411-0300) airplanes and on Model 421 (Serial Numbers 421-0001 thru 421B0048) airplanes, within 10 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 100 hours' time in service from the date of the last inspection, visually inspect the lower surface of the wings in the area of the auxiliary fuel cells for stains or leakage. If auxiliary fuel cell leakage is observed, prior to further flight, replace the auxiliary fuel cells with improved auxiliary fuel cells in accordance with Cessna Service Letter ME72-8, dated April 21, 1972, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. The repetitive inspections required in this paragraph may be discontinued when the improved auxiliary fuel cells are installed. This amendment becomes effective June 2, 1972. FOOTER:
Document Text
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AD Final Rules - DRS_72-11-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 72-11-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes Subject: Auxiliary Fuel Cell Leaks Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/02/1972 Make: Cessna Aircraft Company Model: 411 | 411A | 421 | 421A | 421B | 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: 72-11-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1454 AD NUMBER: 72-11-05 SUBJECT HEADING: Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes ACTION: SUMMARY: DATES: Effective June 2, 1972. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 72-11-05 CESSNA: Amdt. 39-1454. Applies to Models 411 and 421 series airplanes. Compliance: Required as indicated, unless already accomplished. In order to detect auxiliary fuel cell leakage that could result in possible fire and explosion hazards from fuel vapor ignition, accomplish the following: A) On Model 411 (Serial Numbers 411-0001 thru 411-0200) airplanes: 1) Within 10 hours' time in service after the effective date of this AD, and thereafter prior to the first flight of each day, visually inspect the lower surface of the wings in the area of the auxiliary fuel cells for fuel stains and leakage. If auxiliary fuel cell leakage is observed, prior to further flight, replace the auxiliary fuel cells with improved auxiliary fuel cells in accordance with Cessna Service Letter ME72-8, dated April 21, 1972, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. 2) The repetitive inspections required prior to the first flight of each day may be performed by the pilot, including pilots of aircraft engaged in air taxi operations. A chronological listing of compliance with this AD must be made in the airplane's permanent maintenance log in accordance with FAR 91.173. 3) On or before January 1, 1973, replace all auxiliary fuel cells with the improved auxiliary fuel cells specified in Cessna Service Letter ME72-8, dated April 21, 1972. 4) The repetitive inspections required in Paragraph A(1) may be discontinued when the improved auxiliary fuel cells are installed. B) On Model 411 (Serial Numbers 411-0201 thru 411-0300) airplanes and on Model 421 (Serial Numbers 421-0001 thru 421B0048) airplanes, within 10 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 100 hours' time in service from the date of the last inspection, visually inspect the lower surface of the wings in the area of the auxiliary fuel cells for stains or leakage. If auxiliary fuel cell leakage is observed, prior to further flight, replace the auxiliary fuel cells with improved auxiliary fuel cells in accordance with Cessna Service Letter ME72-8, dated April 21, 1972, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. The repetitive inspections required in this paragraph may be discontinued when the improved auxiliary fuel cells are installed. This amendment becomes effective June 2, 1972. FOOTER:
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Retrieved: Apr 8, 2026
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