AD 74-06-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150 | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150A | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150B | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150C | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150D | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150E | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150F | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150G | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150H | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150J | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150K | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150L | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 150M | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 170 | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 170A | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 170B | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172 | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172A | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172B | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172C | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172D | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172E | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172F (USAF T-41A) | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172G | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172H (USAF T-41A) | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172I | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172K | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172L | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172M | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172N | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172P | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172Q | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172R | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172RG | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 172S | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 175 | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 175A | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 175B | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | 175C | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
| aircraft | Cessna Aircraft Company | Piper Aircraft Inc. | PA-28-140 | Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes |
Unsafe Condition
Possible leakage of carbon monoxide into the cabin heater system due to cracks or leakage in the muffler inner shroud flare and tail pipe weld area.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the muffler inner shroud flare and tail pipe weld area for cracks or leakage prior to further flight. If cracks or leaks are found, replace the muffler with a serviceable unit. Safety wire the cabin heat control in the 'Off' position if no issues are found. Replace the existing muffler with a serviceable unit within 25 hours' time in service after the AD's effective date.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to further flight (for inspection and safety wiring) and within 25 hours' time in service after the effective date for muffler replacement.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Cessna Models 150, 170, 172, 175 and Piper Model PA-28-140 airplanes modified with STCs SA750CE, SA806CE, SA807CE, SA777CE, or SA793CE using Avcon Kits with specified serial numbers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
AVCON Mufflers
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_74-06-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-06-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes Subject: AVCON Mufflers Status: Current Citation: This information is not available. Citation Publish Date: 03/13/1974 Effective Date: 03/18/1974 Make: Cessna Aircraft Company | Piper Aircraft Inc. Model: 150 | 150A | 150B | 150C | 150D | 150E | 150F | 150G | 150H | 150J | 150K | 150L | 150M | 170 | 170A...Show more Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-720: Operational Safety Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 74-06-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1798 AD NUMBER: 74-06-02 SUBJECT HEADING: Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes ACTION: SUMMARY: DATES: Effective March 18, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-06-02 CESSNA AND PIPER: Amendment 39-1798. Applies to Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 airplanes modified in accordance with STCs SA750CE, SA806CE, SA807CE, SA777CE or SA 793CE respectively utilizing Avcon Industries, Inc., kits incorporating defective mufflers. Compliance: Required as indicated, unless already accomplished. To prevent possible leakage of carbon monoxide into the cabin heater system, accomplish the following: A) Prior to further flight, except that the aircraft may be flown in accordance with FAR 21.197 to a base where the inspection may be performed provided that the cabin heater system is in the "Off" position and the cabin fresh air vents are open, and at repetitive intervals not to exceed 5 hours' time in service thereafter, inspect the muffler inner shroud as follows: 1) Remove muffler outer shroud assembly. 2) Visually inspect the inner shroud flare and tail pipe weld area for evidence of cracks or leakage. If cracks or leaks are found, replace the muffler prior to further flight with a serviceable unit. 3) If no cracks or leakage are found during the inspection, safety wire the cabin heat control in the "Off" position. B) Within the next 25 hours' time in service after the effective date of this AD, replace the existing muffler with a serviceable unit, at which time compliance with Paragraph A is no longer required. C) Any alternate method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. Avcon Industries Service Letter No. 1, dated February 19, 1974, pertains to this subject matter. NOTE: The defective mufflers are contained in Avcon Kits of the following serial numbers: 556, 557, 562, 565, 580, 583, 584, 585, 588, 589, 591, 596, 597, 598, 599, 603, 604, 605, 608, 612, 618, 621, 623, 624, 627, 628, 632, 640, 642, 643, 644, 649, 650, 656, 659, 668, 669, 674 and 690. Confirmation of affected aircraft can be obtained by comparing the Avcon serial number stamped on the STC Kit I.D. tag with the Avcon serial number noted above. STC Kit I.D. tags are mounted near the aircraft manufacturer's I.D. tag. This amendment becomes effective March 18, 1974, to all persons except those to whom it was made effective by letter dated February 22, 1974. FOOTER:
Document Text
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AD Final Rules - DRS_74-06-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-06-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes Subject: AVCON Mufflers Status: Current Citation: This information is not available. Citation Publish Date: 03/13/1974 Effective Date: 03/18/1974 Make: Cessna Aircraft Company | Piper Aircraft Inc. Model: 150 | 150A | 150B | 150C | 150D | 150E | 150F | 150G | 150H | 150J | 150K | 150L | 150M | 170 | 170A...Show more Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: AIR-700: Compliance & Airworthiness Division Office of Primary Responsibility: AIR-720: Operational Safety Branch CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 74-06-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1798 AD NUMBER: 74-06-02 SUBJECT HEADING: Airworthiness Directives; Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 Airplanes ACTION: SUMMARY: DATES: Effective March 18, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-06-02 CESSNA AND PIPER: Amendment 39-1798. Applies to Cessna Models 150, 170, 172 and 175 and Piper Model PA-28-140 airplanes modified in accordance with STCs SA750CE, SA806CE, SA807CE, SA777CE or SA 793CE respectively utilizing Avcon Industries, Inc., kits incorporating defective mufflers. Compliance: Required as indicated, unless already accomplished. To prevent possible leakage of carbon monoxide into the cabin heater system, accomplish the following: A) Prior to further flight, except that the aircraft may be flown in accordance with FAR 21.197 to a base where the inspection may be performed provided that the cabin heater system is in the "Off" position and the cabin fresh air vents are open, and at repetitive intervals not to exceed 5 hours' time in service thereafter, inspect the muffler inner shroud as follows: 1) Remove muffler outer shroud assembly. 2) Visually inspect the inner shroud flare and tail pipe weld area for evidence of cracks or leakage. If cracks or leaks are found, replace the muffler prior to further flight with a serviceable unit. 3) If no cracks or leakage are found during the inspection, safety wire the cabin heat control in the "Off" position. B) Within the next 25 hours' time in service after the effective date of this AD, replace the existing muffler with a serviceable unit, at which time compliance with Paragraph A is no longer required. C) Any alternate method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. Avcon Industries Service Letter No. 1, dated February 19, 1974, pertains to this subject matter. NOTE: The defective mufflers are contained in Avcon Kits of the following serial numbers: 556, 557, 562, 565, 580, 583, 584, 585, 588, 589, 591, 596, 597, 598, 599, 603, 604, 605, 608, 612, 618, 621, 623, 624, 627, 628, 632, 640, 642, 643, 644, 649, 650, 656, 659, 668, 669, 674 and 690. Confirmation of affected aircraft can be obtained by comparing the Avcon serial number stamped on the STC Kit I.D. tag with the Avcon serial number noted above. STC Kit I.D. tags are mounted near the aircraft manufacturer's I.D. tag. This amendment becomes effective March 18, 1974, to all persons except those to whom it was made effective by letter dated February 22, 1974. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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