AD 51-28-02
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-178-B3 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-178-B31 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-178-B32 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-178-B33 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-200-C32 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
| engine | Wytwornia Sprzetu Komunikacyjnego | 6V4-200-C33 | FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines |
Unsafe Condition
Oil pump gears (P/N 10673 and 17736) may experience excessive galling leading to failure.
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Required Actions
Inspect oil pump gears at each 300 hours of operation. Replace excessively galled gears. If replacing with same part numbers, continue 300-hour inspections. Install carbonitrided gears (P/N 19377 and 19373) to eliminate inspections, and stamp engine nameplate with suffix 'P'.
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Compliance Time
Compliance required as indicated.
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Affected Aircraft
FRANKLIN Model 6V4-178 Series Engines prior to serial number 17690 and 6V4-200 Series Engines prior to serial number 26235.
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Federal Register Abstract
Oil Pump Gears
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_51-28-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 51-28-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines Subject: Oil Pump Gears Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Wytwornia Sprzetu Komunikacyjnego Model: 6V4-178-B3 | 6V4-178-B31 | 6V4-178-B32 | 6V4-178-B33 | 6V4-200-C32 | 6V4-200-C33 Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 51-28-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 51-28-02 SUBJECT HEADING: FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 51-28-02 FRANKLIN: Applies to Model 6V4-178 Series Engines Prior to Serial Number 17690 and 6V4- 200 Series Engines Prior to Serial Number 26235. Compliance required as indicated. To preclude the possibility of oil pump failure, oil pump gears (P/N 10673 and 17736) must be inspected at each 300 hours of operation. Excessively galled gears must be replaced. If same part numbers are used for replacements, the 300-hour inspections will still apply. If carbonitrided oil pump drive gear, P/N 19377, and oil pump driven gear, P/N 19373, are installed, no further inspection is required. When these new carbonitrided gears are installed, suffix "P" must be stamped after the serial number of the engine on the nameplate - example: No. 1700P. (Franklin Service Bulletin No. 86, revised November 1, 1951, covers this same subject.) This supersedes AD's 51-22-02 and 51-11-03. FOOTER:
Document Text
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AD Final Rules - DRS_51-28-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 51-28-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines Subject: Oil Pump Gears Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Wytwornia Sprzetu Komunikacyjnego Model: 6V4-178-B3 | 6V4-178-B31 | 6V4-178-B32 | 6V4-178-B33 | 6V4-200-C32 | 6V4-200-C33 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: 51-28-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 51-28-02 SUBJECT HEADING: FRANKLIN Model 6V4-178 and 6V4- 200 Series Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 51-28-02 FRANKLIN: Applies to Model 6V4-178 Series Engines Prior to Serial Number 17690 and 6V4- 200 Series Engines Prior to Serial Number 26235. Compliance required as indicated. To preclude the possibility of oil pump failure, oil pump gears (P/N 10673 and 17736) must be inspected at each 300 hours of operation. Excessively galled gears must be replaced. If same part numbers are used for replacements, the 300-hour inspections will still apply. If carbonitrided oil pump drive gear, P/N 19377, and oil pump driven gear, P/N 19373, are installed, no further inspection is required. When these new carbonitrided gears are installed, suffix "P" must be stamped after the serial number of the engine on the nameplate - example: No. 1700P. (Franklin Service Bulletin No. 86, revised November 1, 1951, covers this same subject.) This supersedes AD's 51-22-02 and 51-11-03. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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