AD 68-12-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT4A-10 | PRATT & WHITNEY Model JT4A Series Engines |
| engine | Pratt & Whitney Division | JT4A-11 | PRATT & WHITNEY Model JT4A Series Engines |
| engine | Pratt & Whitney Division | JT4A-12 | PRATT & WHITNEY Model JT4A Series Engines |
| engine | Pratt & Whitney Division | JT4A-3 | PRATT & WHITNEY Model JT4A Series Engines |
| engine | Pratt & Whitney Division | JT4A-5 | PRATT & WHITNEY Model JT4A Series Engines |
| engine | Pratt & Whitney Division | JT4A-9 | PRATT & WHITNEY Model JT4A Series Engines |
Unsafe Condition
High Compressor Rotor Blade Failure
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Required Actions
Rework all diffuser case assemblies with part numbers 361176, 397231, 419006, 406242, 429614, 447328, and 450862 in accordance with Pratt & Whitney Service Bulletin No. 1033 or FAA-approved revisions. Compliance must be completed within 11,000 hours' time in service after the effective date of this AD.
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Compliance Time
within the next 11,000 hours' time in service after the effective date of this AD
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Affected Aircraft
Pratt & Whitney Model JT4A Series Engines including JT4A-10, JT4A-11, JT4A-12, JT4A-3, JT4A-5, and JT4A-9 models
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Federal Register Abstract
High Compressor Rotor Blade Failure
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_68-12-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 68-12-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT4A Series Engines Subject: High Compressor Rotor Blade Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/12/1968 Make: Pratt & Whitney Division Model: JT4A-10 | JT4A-11 | JT4A-12 | JT4A-3 | JT4A-5 | JT4A-9 Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 68-12-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-608 AD NUMBER: 68-12-03 SUBJECT HEADING: PRATT & WHITNEY Model JT4A Series Engines ACTION: SUMMARY: DATES: Effective June 12, 1968. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 68-12-03 PRATT & WHITNEY: Amendment 39-608. Applies to all Model JT4A Series Turbojet Engines. Compliance required as indicated unless previously accomplished.: To preclude penetration of the diffuser case in the event of a high compressor rotor blade failure, accomplish the following: Within the next 11,000 hours' time in service after the effective date of this AD, rework all P/N's 361176, 397231, 419006, 406242, 429614, 447328, and 450862 diffuser case assemblies in accordance with Pratt & Whitney Aircraft Turbojet Engine Service Bulletin No. 1033 dated September 8, 1965, and FAA-approved revisions or an equivalent modification approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment becomes effective June 12, 1968. FOOTER:
Document Text
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AD Final Rules - DRS_68-12-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 68-12-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT4A Series Engines Subject: High Compressor Rotor Blade Failure Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 06/12/1968 Make: Pratt & Whitney Division Model: JT4A-10 | JT4A-11 | JT4A-12 | JT4A-3 | JT4A-5 | JT4A-9 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: 68-12-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-608 AD NUMBER: 68-12-03 SUBJECT HEADING: PRATT & WHITNEY Model JT4A Series Engines ACTION: SUMMARY: DATES: Effective June 12, 1968. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 68-12-03 PRATT & WHITNEY: Amendment 39-608. Applies to all Model JT4A Series Turbojet Engines. Compliance required as indicated unless previously accomplished.: To preclude penetration of the diffuser case in the event of a high compressor rotor blade failure, accomplish the following: Within the next 11,000 hours' time in service after the effective date of this AD, rework all P/N's 361176, 397231, 419006, 406242, 429614, 447328, and 450862 diffuser case assemblies in accordance with Pratt & Whitney Aircraft Turbojet Engine Service Bulletin No. 1033 dated September 8, 1965, and FAA-approved revisions or an equivalent modification approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This amendment becomes effective June 12, 1968. FOOTER:
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Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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Related Airworthiness Directives
76-01-08
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Unsafe Condition: Tenth stage compressor blade failure resulting in case penetration.
71-06-03
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Unsafe Condition: Twelfth stage compressor rotor disc failure as a result of suspected material deficiency.
71-02-02
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Unsafe Condition: Twelfth stage compressor rotor disc failure as a result of suspected material deficiency.
67-01-03
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