AD 85-20-01

final rule

Airworthiness Directives; Cessna Model 172RG Airplanes

AD Number
85-20-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Cessna Aircraft Company 172RG Airworthiness Directives; Cessna Model 172RG Airplanes

Unsafe Condition

Carbon monoxide contamination entering the cabin area due to potential failure of the cabin heat system, including improper muffler core installation or damaged muffler core from drilling holes through the end plate or improper length attachment screws.

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

Required Actions

Deactivate the cabin heat system by removing the control cable and ensuring the valve spring mechanism functions or safety wiring the valve closed. Install a placard stating 'DO NOT USE CABIN HEAT' on the instrument panel. Inspect the muffler core for damage within 25 hours time-in-service after the AD's effective date and replace if damaged. Report defects within 10 days of inspection.

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

Compliance Time

Prior to further flight for cabin heat deactivation and placard installation; within 25 hours time-in-service after the effective date for muffler inspection and replacement if needed.

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

Affected Aircraft

Cessna Model 172RG (Serial Numbers 172RG1135 thru 172RG1187)

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

Federal Register Abstract

Cabin Heat Deactivated

Applicability Source Text

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AD Final Rules - DRS_85-20-01.html
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AD Number:
85-20-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Cessna Model 172RG Airplanes
Subject:
Cabin Heat Deactivated
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1985
Make:
Cessna Aircraft Company
Model:
172RG
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Superseded AD: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Superseded By: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: 85-20-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-5175

AD NUMBER:   85-20-01

SUBJECT HEADING:   Airworthiness Directives; Cessna Model 172RG Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1985.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
85-20-01 CESSNA: Amendment 39-5175. Applies to Model 172RG (Serial Numbers 172RG1135 thru 172RG1187) airplanes certificated in any category.

Compliance: Required as indicated, unless already accomplished. To reduce the possibility of carbon monoxide contamination entering the cabin area, accomplish the following:

(a) Prior to further flight:

1) Deactivate the cabin heat system by removing the cabin heat control cable from the control arm on the cabin heat valve located on the firewall at the right upper side of the engine compartment. Ensure that the valve spring mechanism is functioning and that the cabin heat valve is spring loaded to the closed position or safety wire the valve to the closed position.

2) Fabricate and install on the instrument panel visible to the pilot the following placard using letters of a minimum 0.10 inch in height: "DO NOT USE CABIN HEAT", and operate the airplane accordingly.

(b) Within 25 hours time-in-service after the effective date of this AD, remove the muffler shroud and visually inspect the muffler core for damage as a result of drilling the holes through the end plate or improper length attachment screws and if damaged replace the muffler core prior to further flight.

(c) The requirements of paragraph (a) of this AD are no longer required when paragraph (b) of this AD has been accomplished.

(d) The airplane may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished, providing cabin heat is not used during the flight.

(e) An equivalent method of compliance may be used when approved by the Manager, Wichita Aircraft Certification Office, Federal Aviation Administration, Central Region, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209.

(f) Report, in writing, all defects found to the Manager, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209, within 10 days of the inspection required by paragraph (b) of this AD (Reporting approved by the Office of Management and Budget under OMB No. 2120-0056).

This amendment became effective on December 5, 1985, to all persons except those to whom it has already been made effective by priority letter from the FAA dated September 27, 1985, and is identified as AD 85-20-01.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_85-20-01.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
85-20-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Cessna Model 172RG Airplanes
Subject:
Cabin Heat Deactivated
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1985
Make:
Cessna Aircraft Company
Model:
172RG
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: 85-20-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-5175

AD NUMBER:   85-20-01

SUBJECT HEADING:   Airworthiness Directives; Cessna Model 172RG Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1985.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
85-20-01 CESSNA: Amendment 39-5175. Applies to Model 172RG (Serial Numbers 172RG1135 thru 172RG1187) airplanes certificated in any category.

Compliance: Required as indicated, unless already accomplished. To reduce the possibility of carbon monoxide contamination entering the cabin area, accomplish the following:

(a) Prior to further flight:

1) Deactivate the cabin heat system by removing the cabin heat control cable from the control arm on the cabin heat valve located on the firewall at the right upper side of the engine compartment. Ensure that the valve spring mechanism is functioning and that the cabin heat valve is spring loaded to the closed position or safety wire the valve to the closed position.

2) Fabricate and install on the instrument panel visible to the pilot the following placard using letters of a minimum 0.10 inch in height: "DO NOT USE CABIN HEAT", and operate the airplane accordingly.

(b) Within 25 hours time-in-service after the effective date of this AD, remove the muffler shroud and visually inspect the muffler core for damage as a result of drilling the holes through the end plate or improper length attachment screws and if damaged replace the muffler core prior to further flight.

(c) The requirements of paragraph (a) of this AD are no longer required when paragraph (b) of this AD has been accomplished.

(d) The airplane may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished, providing cabin heat is not used during the flight.

(e) An equivalent method of compliance may be used when approved by the Manager, Wichita Aircraft Certification Office, Federal Aviation Administration, Central Region, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209.

(f) Report, in writing, all defects found to the Manager, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209, within 10 days of the inspection required by paragraph (b) of this AD (Reporting approved by the Office of Management and Budget under OMB No. 2120-0056).

This amendment became effective on December 5, 1985, to all persons except those to whom it has already been made effective by priority letter from the FAA dated September 27, 1985, and is identified as AD 85-20-01.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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