AD 74-13-05
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | IGO-540-A1A | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGO-540-A1B | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGO-540-A1C | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGO-540-B1A | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGO-540-B1B | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGO-540-B1C | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-A1A | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-A1C | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-A1D | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-A1E | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-A1F | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-B1A | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
| engine | Lycoming Engines | IGSO-540-B1C | AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines |
Unsafe Condition
Failures of connecting rod assemblies P/N 72606, P/N 73174, and P/N 75548.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace connecting rod assemblies with new P/N 77450 within the next 50 hours in service if accumulated 400 hours or more since new or overhaul. Replace within the next 100 hours in service if less than 400 hours since new or overhaul. Compliance time may be increased by the FAA Chief, Engineering and Manufacturing Branch upon request with substantiating data.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 50 hours in service (for engines with 400+ hours) or within the next 100 hours in service (for engines with less than 400 hours), or as increased by FAA upon request.
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Affected Aircraft
AVCO Lycoming Model IGO-540 series engines except serials 311-49 and subsequent; IGSO-540 series engines except serial ranges 2558-50 through 2563-50, 2565-50 through 2582-50, 2584-50 through 2589-50, 2591-50 through 2602-50, 2606-50 through 2631-50, 2637-50, 2640-50, 2647-50 through 2652-50, 2657-50 through 2692-50, 2694-50 through 2713-50, 2718-50 through 2727-50, 2730-50 through 2750-50, 2752-50 and subsequent; and except engines overhauled by Lycoming after October 29, 1970.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Connecting Rod Assemblies
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_74-13-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-13-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines Subject: Connecting Rod Assemblies Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/21/1974 Make: Lycoming Engines Model: IGO-540-A1A | IGO-540-A1B | IGO-540-A1C | IGO-540-B1A | IGO-540-B1B | IGO-540-B1C | IGSO-540-A1A | I...Show more Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 74-13-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1876 AD NUMBER: 74-13-05 SUBJECT HEADING: AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines ACTION: SUMMARY: DATES: Effective June 21, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-13-05 AVCO LYCOMING: Amendment 39-1876. Applies to all IGO-540 series engines except IGO- 540 series engines with serials Nos. 311-49 and subsequent; and to all IGSO-540 series engines except IGSO-540 series engines with serials Nos. 2558-50 through 2563-50, 2565-50 through 2582-50, 2584-50 through 2589-50, 2591-50 through 2602-50, 2606-50 through 2631-50, 2637-50, 2640-50, 2647-50 through 2652-50, 2657-50 through 2692-50, 2694-50 through 2713-50, 2718-50 through 2727-50, 2730-50 through 2750-50, 2752-50 and subsequent; and except all IGO and IGSO-540 series engines overhauled (also known as remanufactured) by Lycoming after October 29, 1970. Compliance required as indicated after the effective date of this AD, unless already accomplished. To prevent failures of connecting rod assemblies P/N 72606, P/N 73174, and P/N 75548, accomplish the following: (a) Engines with connecting rod assemblies that have accumulated 400 hours or more in service since new or overhaul must have the connecting rod assemblies replaced with new connecting rod assembly, P/N 77450, within the next 50 hours in service. (b) Engines that have connecting rod assemblies with less than 400 hours in service since new or overhauled must have the connecting rod assemblies replaced with new connecting rod assembly, P/N 77450, within the next 100 hours in service. (c) Upon request, with substantiating data submitted through an FAA maintenance inspector, the compliance time may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. NOTE. Lycoming Service Bulletin No. 351A covers this subject. This amendment is effective June 21, 1974. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_74-13-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-13-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines Subject: Connecting Rod Assemblies Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/21/1974 Make: Lycoming Engines Model: IGO-540-A1A | IGO-540-A1B | IGO-540-A1C | IGO-540-B1A | IGO-540-B1B | IGO-540-B1C | IGSO-540-A1A | I...Show more Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 74-13-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1876 AD NUMBER: 74-13-05 SUBJECT HEADING: AVCO LYCOMING Model IGO-540 Series Engines and IGSO-540 Series Engines ACTION: SUMMARY: DATES: Effective June 21, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-13-05 AVCO LYCOMING: Amendment 39-1876. Applies to all IGO-540 series engines except IGO- 540 series engines with serials Nos. 311-49 and subsequent; and to all IGSO-540 series engines except IGSO-540 series engines with serials Nos. 2558-50 through 2563-50, 2565-50 through 2582-50, 2584-50 through 2589-50, 2591-50 through 2602-50, 2606-50 through 2631-50, 2637-50, 2640-50, 2647-50 through 2652-50, 2657-50 through 2692-50, 2694-50 through 2713-50, 2718-50 through 2727-50, 2730-50 through 2750-50, 2752-50 and subsequent; and except all IGO and IGSO-540 series engines overhauled (also known as remanufactured) by Lycoming after October 29, 1970. Compliance required as indicated after the effective date of this AD, unless already accomplished. To prevent failures of connecting rod assemblies P/N 72606, P/N 73174, and P/N 75548, accomplish the following: (a) Engines with connecting rod assemblies that have accumulated 400 hours or more in service since new or overhaul must have the connecting rod assemblies replaced with new connecting rod assembly, P/N 77450, within the next 50 hours in service. (b) Engines that have connecting rod assemblies with less than 400 hours in service since new or overhauled must have the connecting rod assemblies replaced with new connecting rod assembly, P/N 77450, within the next 100 hours in service. (c) Upon request, with substantiating data submitted through an FAA maintenance inspector, the compliance time may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. NOTE. Lycoming Service Bulletin No. 351A covers this subject. This amendment is effective June 21, 1974. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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