AD 68-12-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Corporation | 250-C10B (T63-A-5A) | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
| engine | Rolls-Royce Corporation | 250-C18 | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
| engine | Rolls-Royce Corporation | 250-C18A | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
| engine | Rolls-Royce Corporation | 250-C18B | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
| engine | Rolls-Royce Corporation | 250-C18C | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
| engine | Rolls-Royce Corporation | 250-C19 | ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. |
Unsafe Condition
Compressor blades in the sixth stage of the engines may fail, which could result in engine failure.
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Required Actions
Modify the sixth stage compressor blades in accordance with Allison Commercial Engine Bulletin No. 250 CEB-48 or an approved method.
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Compliance Time
Before further flight
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Affected Aircraft
Rolls-Royce Corporation Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19, and 250-C10B engines.
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Federal Register Abstract
Compressor Blades
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_68-12-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 68-12-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. Subject: Compressor Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/18/1968 Make: Rolls-Royce Corporation Model: 250-C10B (T63-A-5A) | 250-C18 | 250-C18A | 250-C18B | 250-C18C | 250-C19 Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 68-12-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-612 AD NUMBER: 68-12-06 SUBJECT HEADING: ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. ACTION: SUMMARY: DATES: Effective June 18, 1968. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 68-12-06 ALLISON: Amdt. 39-612. Applies to Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250- C19 and 250-C10B engines. Before further flight of any aircraft equipped with one of the Allison model engines listed above, unless already accomplished, modify the sixth stage compressor blades in these engines in accordance with Allison Commercial Engine Bulletin No. 250 CEB-48, dated June 11, 1968, or any other method approved by the Chief, Engineering and Manufacturing Branch, Central Region. Further flight beyond the point where an aircraft equipped with one of these engines is grounded pursuant to this Airworthiness Directive, may be conducted only in accordance with Federal Aviation Regulation 21.197. This amendment becomes effective June 18, 1968. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_68-12-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 68-12-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. Subject: Compressor Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/18/1968 Make: Rolls-Royce Corporation Model: 250-C10B (T63-A-5A) | 250-C18 | 250-C18A | 250-C18B | 250-C18C | 250-C19 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: 68-12-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-612 AD NUMBER: 68-12-06 SUBJECT HEADING: ALLISON Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250-C19 and 250-C10B Engines. ACTION: SUMMARY: DATES: Effective June 18, 1968. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 68-12-06 ALLISON: Amdt. 39-612. Applies to Models 250-C18, 250-C18A, 250-C18B, 250-C18C, 250- C19 and 250-C10B engines. Before further flight of any aircraft equipped with one of the Allison model engines listed above, unless already accomplished, modify the sixth stage compressor blades in these engines in accordance with Allison Commercial Engine Bulletin No. 250 CEB-48, dated June 11, 1968, or any other method approved by the Chief, Engineering and Manufacturing Branch, Central Region. Further flight beyond the point where an aircraft equipped with one of these engines is grounded pursuant to this Airworthiness Directive, may be conducted only in accordance with Federal Aviation Regulation 21.197. This amendment becomes effective June 18, 1968. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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