AD 73-20-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | R172E | Airworthiness Directives; CESSNA Model R172E (T-41B) Airplanes |
Unsafe Condition
Complete loss of engine power when using the fuel boost pump due to the fuel pump boost electrical circuit design.
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Required Actions
Install a new boost pump switch, electrical resistors, and placard in accordance with Cessna Service Letter No. SE73-24 and Service Kit SK172-43, or later FAA-approved revisions, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.
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Compliance Time
Within 50 hours' time in service after the effective date of this AD
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Affected Aircraft
Cessna Model R172E (T-41B) airplanes with serial numbers R172-0001 through R172-0256
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Federal Register Abstract
Fuel Pump Boost Electrical Circuit
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_73-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model R172E (T-41B) Airplanes Subject: Fuel Pump Boost Electrical Circuit Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/03/1973 Make: Cessna Aircraft Company Model: R172E Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1726 AD NUMBER: 73-20-04 SUBJECT HEADING: Airworthiness Directives; CESSNA Model R172E (T-41B) Airplanes ACTION: SUMMARY: DATES: Effective October 3, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-20-04 CESSNA: Amendment 39-1726. Applies to Model R172E (T-41B) Serial Numbers R172-0001 through R172-0256) airplanes. Compliance: Within 50 hours' time in service after the effective date of this AD, unless already accomplished. To prevent complete loss of engine power when using the fuel boost pump, accomplish the following: Modify the fuel boost pump electrical circuit by installing a new boost pump switch, electrical resistors, and placard in accordance with Cessna Service Letter No. SE73-24, dated August 24, 1973, and Service Kit SK172-43, or later FAA-approved revisions, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. This amendment becomes effective October 3, 1973. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_73-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; CESSNA Model R172E (T-41B) Airplanes Subject: Fuel Pump Boost Electrical Circuit Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/03/1973 Make: Cessna Aircraft Company Model: R172E 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: 73-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1726 AD NUMBER: 73-20-04 SUBJECT HEADING: Airworthiness Directives; CESSNA Model R172E (T-41B) Airplanes ACTION: SUMMARY: DATES: Effective October 3, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-20-04 CESSNA: Amendment 39-1726. Applies to Model R172E (T-41B) Serial Numbers R172-0001 through R172-0256) airplanes. Compliance: Within 50 hours' time in service after the effective date of this AD, unless already accomplished. To prevent complete loss of engine power when using the fuel boost pump, accomplish the following: Modify the fuel boost pump electrical circuit by installing a new boost pump switch, electrical resistors, and placard in accordance with Cessna Service Letter No. SE73-24, dated August 24, 1973, and Service Kit SK172-43, or later FAA-approved revisions, or any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. This amendment becomes effective October 3, 1973. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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