AD 66-14-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | O-540-B2B5 | LYCOMING Model O-540-B2B5 Engines |
Unsafe Condition
Failure of crankshaft idler shafts, specifically part number 70390, in Lycoming Model O-540-B2B5 engines.
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Required Actions
Replace crankshaft idler shaft P/N 70390 with P/N 73014 and accessory housing P/N 71648 with P/N 75367 or 71648-85. Compliance must be done before specific time-in-service thresholds based on engine usage.
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Compliance Time
Compliance required before accumulation of 400 hours' time in service since overhaul or new, or within next 100 hours' time in service depending on engine's time-in-service on the effective date.
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Affected Aircraft
Lycoming Model O-540-B2B5 engines, serial numbers 101-40 through 8267-40, installed in Piper PA-25 and Intermountain Manufacturing Company airplanes, except engines remanufactured at Lycoming after November 14, 1965.
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Federal Register Abstract
Crankshaft Idler Shafts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_66-14-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 66-14-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LYCOMING Model O-540-B2B5 Engines Subject: Crankshaft Idler Shafts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/09/1966 Make: Lycoming Engines Model: O-540-B2B5 Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 66-14-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-248 AD NUMBER: 66-14-03 SUBJECT HEADING: LYCOMING Model O-540-B2B5 Engines ACTION: SUMMARY: DATES: Effective July 9, 1966. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 66-14-03 LYCOMING: Amdt. 39-248, Part 39, Federal Register June 8, 1966. Applies to Model O-540- B2B5 Engines, Serial Numbers 101-40 through 8267-40, Installed in Piper PA-25 and Intermountain Manufacturing Company Airplanes, Except Engines Remanufactured at Lycoming after November 14, 1965. Compliance required as indicated, unless already accomplished. To prevent further failures of crankshaft idler shafts, accomplish the following: (a) For engines with less than 300 hours' time in service on the effective date of this AD since overhaul, comply with (d) before the accumulation of 400 hours' time in service since overhaul. (b) For engines with less than 300 hours' time in service on the effective date of this AD since new that have never been overhauled, comply with (d) before the accumulation of 400 hours' time in service since new. (c) For engines with 300 or more hours' time in service on the effective date of this AD since new or overhaul, comply with (d) within the next 100 hours' time in service. (d) Replace crankshaft idler shaft, P/N 70390, and accessory housing, P/N 71648, with crankshaft idler shaft, P/N 73014, and accessory housing, P/N 75367 or 71648-85. (Lycoming Service Bulletin No. 308 pertains to this subject.) This directive effective July 9, 1966. FOOTER:
Document Text
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AD Final Rules - DRS_66-14-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 66-14-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: LYCOMING Model O-540-B2B5 Engines Subject: Crankshaft Idler Shafts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/09/1966 Make: Lycoming Engines Model: O-540-B2B5 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: AIRWORTHINESS DIRECTIVES FINAL RULES: 66-14-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-248 AD NUMBER: 66-14-03 SUBJECT HEADING: LYCOMING Model O-540-B2B5 Engines ACTION: SUMMARY: DATES: Effective July 9, 1966. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 66-14-03 LYCOMING: Amdt. 39-248, Part 39, Federal Register June 8, 1966. Applies to Model O-540- B2B5 Engines, Serial Numbers 101-40 through 8267-40, Installed in Piper PA-25 and Intermountain Manufacturing Company Airplanes, Except Engines Remanufactured at Lycoming after November 14, 1965. Compliance required as indicated, unless already accomplished. To prevent further failures of crankshaft idler shafts, accomplish the following: (a) For engines with less than 300 hours' time in service on the effective date of this AD since overhaul, comply with (d) before the accumulation of 400 hours' time in service since overhaul. (b) For engines with less than 300 hours' time in service on the effective date of this AD since new that have never been overhauled, comply with (d) before the accumulation of 400 hours' time in service since new. (c) For engines with 300 or more hours' time in service on the effective date of this AD since new or overhaul, comply with (d) within the next 100 hours' time in service. (d) Replace crankshaft idler shaft, P/N 70390, and accessory housing, P/N 71648, with crankshaft idler shaft, P/N 73014, and accessory housing, P/N 75367 or 71648-85. (Lycoming Service Bulletin No. 308 pertains to this subject.) This directive effective July 9, 1966. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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