AD 79-18-13
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Corporation | 250-C28B | DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines |
| engine | Rolls-Royce Corporation | 250-C28C | DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines |
Unsafe Condition
Third stage turbine wheel blade failure due to use of turbine wheels with part numbers 6898553 or 6898773, which could cause engine power loss.
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Required Actions
Remove from service third stage turbine wheels with part numbers 6898553 or 6898773. Compliance is required before reaching 325 hours total time in service for wheels with less than 300 hours, or within 25 hours time in service for wheels with over 300 hours.
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Compliance Time
Before reaching 325 hours total time in service for turbine wheels with less than 300 hours total time in service; within 25 hours time in service for turbine wheels with more than 300 hours total time in service.
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Affected Aircraft
Rolls-Royce Corporation Model 250-C28B and 250-C28C engines equipped with third stage turbine wheel part numbers 6898553 or 6898773 installed in Bell 206L-1 rotorcraft.
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Federal Register Abstract
Third Stage Turbine Wheel
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_79-18-13.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 79-18-13 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines Subject: Third Stage Turbine Wheel Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/06/1979 Make: Rolls-Royce Corporation Model: 250-C28B | 250-C28C Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 79-18-13 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3548 AD NUMBER: 79-18-13 SUBJECT HEADING: DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines ACTION: SUMMARY: DATES: Effective September 6, 1979. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 79-18-13 DETROIT DIESEL ALLISON: Amendment 39-3548. Applies to all Model 250-C28B and 250-C28C Series engines equipped with third stage turbine wheel P/Ns 6898553 or 6898773 installed in, but not limited to Bell 206L-1 rotorcraft certificated in all categories. Compliance required as indicated unless previously accomplished. A. For turbine wheels with less than 300 hours total time in service, compliance is required before reaching 325 hours total time in service. B. For turbine wheels with more than 300 hours total time in service, compliance is required within 25 hours time in service. To preclude engine power loss due to possible turbine blade failure, remove above listed third stage turbine wheels from service. This amendment becomes effective September 6, 1979, as to all persons except those to whom it was made immediately effective by the airmail letter dated July 19, 1979, which contained this amendment. FOOTER:
Document Text
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AD Final Rules - DRS_79-18-13.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 79-18-13 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines Subject: Third Stage Turbine Wheel Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 09/06/1979 Make: Rolls-Royce Corporation Model: 250-C28B | 250-C28C 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: 79-18-13 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3548 AD NUMBER: 79-18-13 SUBJECT HEADING: DETROIT DIESEL ALLISON Model 250-C28B and 250-C28C Series Engines ACTION: SUMMARY: DATES: Effective September 6, 1979. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 79-18-13 DETROIT DIESEL ALLISON: Amendment 39-3548. Applies to all Model 250-C28B and 250-C28C Series engines equipped with third stage turbine wheel P/Ns 6898553 or 6898773 installed in, but not limited to Bell 206L-1 rotorcraft certificated in all categories. Compliance required as indicated unless previously accomplished. A. For turbine wheels with less than 300 hours total time in service, compliance is required before reaching 325 hours total time in service. B. For turbine wheels with more than 300 hours total time in service, compliance is required within 25 hours time in service. To preclude engine power loss due to possible turbine blade failure, remove above listed third stage turbine wheels from service. This amendment becomes effective September 6, 1979, as to all persons except those to whom it was made immediately effective by the airmail letter dated July 19, 1979, which contained this amendment. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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