AD 71-06-03
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
Twelfth stage compressor rotor disc failure as a result of suspected material deficiency.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the suspect serial number twelfth stage compressor rotor disc either within the next 50 hours in service after the effective date if the disc has 18,000 hours or more in service, or prior to accumulating 18,050 hours in service if the disc has 18,000 hours or less in service. Substantiating data submission may allow compliance time adjustment.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 50 hours in service after the effective date of this AD (May 19, 1971) for discs with 18,000 hours or more in service, or prior to accumulating 18,050 hours in service for discs with 18,000 hours or less in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Model JT4A series engines with 12th stage compressor rotor discs having serial numbers listed in the AD (e.g., 2G5181 to 2G6360, 5F7645 through 5F858, etc.).
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Twelfth Stage Compressor Rotor Disc
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_71-06-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 71-06-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT4A Series Engines Subject: Twelfth Stage Compressor Rotor Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/19/1971 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: 71-06-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1211 AD NUMBER: 71-06-03 SUBJECT HEADING: PRATT & WHITNEY Model JT4A Series Engines ACTION: SUMMARY: DATES: Effective May 19, 1971. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 71-06-03 PRATT & WHITNEY: Amdt. 39-1168 as amended by Amendment 39-1211. Applies to all Pratt & Whitney Aircraft JT4A series turbojet engines which incorporate the following serial number 12th stage compressor rotor disc part number 360112. 2G5181 2G6360 2G5182 2G6362 2G5183 2G6363 2G5446 2G6445 2G5807 2G6448 2G5812 2G6449 2G5818 2G6454 2G5820 2G6581 2G5821 2G6583 2G5825 2G6585 2G5826 3G0201 2G6027 2G6030 5F7645 7 5F858 6F8362 5F7646 5F8588 6F9707 5F8544 through 5F8695 6F9739 5F8547 6F7206 6F9751 5F8550 through 6F7207 6F9753 through 5F8553 6F7210 6F9759 5F8558 6F7214 6F9760 through 5F8576 6F7218 6F9765 5F8577 6F7501 6F9846 5F8581 through 6F7502 6F9853 5F8584 6F7504 6F9861 6F7949 6F9866 6F8168 7F0156 6F8198 7F0480 7F0556 Pratt & Whitney Aircraft telegram PSE/RS/1-3-10-1 covers this same subject. Compliance required as indicated. To preclude twelfth stage compressor rotor disc failure as the result of suspected material deficiency, accomplish the following: 1. For all the previously listed serial number twelfth stage compressor rotor discs: A. With 18,000 hours or more in service within the next 50 hours in service after the effective date of this AD, replace the suspect serial number disc. B. With 18,000 hours or less in service prior to the accumulation of 18,050 hours in service, replace the suspect serial number disc. 2. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time. Amendment 39-1168 was effective March 12, 1971. This amendment 39-1211 is effective May 19, 1971 and was effective for all recipients of the telegram dated March 12, 1971 which contained this amendment. FOOTER:
Document Text
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AD Final Rules - DRS_71-06-03.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 71-06-03 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT4A Series Engines Subject: Twelfth Stage Compressor Rotor Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/19/1971 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: 71-06-03 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1211 AD NUMBER: 71-06-03 SUBJECT HEADING: PRATT & WHITNEY Model JT4A Series Engines ACTION: SUMMARY: DATES: Effective May 19, 1971. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 71-06-03 PRATT & WHITNEY: Amdt. 39-1168 as amended by Amendment 39-1211. Applies to all Pratt & Whitney Aircraft JT4A series turbojet engines which incorporate the following serial number 12th stage compressor rotor disc part number 360112. 2G5181 2G6360 2G5182 2G6362 2G5183 2G6363 2G5446 2G6445 2G5807 2G6448 2G5812 2G6449 2G5818 2G6454 2G5820 2G6581 2G5821 2G6583 2G5825 2G6585 2G5826 3G0201 2G6027 2G6030 5F7645 7 5F858 6F8362 5F7646 5F8588 6F9707 5F8544 through 5F8695 6F9739 5F8547 6F7206 6F9751 5F8550 through 6F7207 6F9753 through 5F8553 6F7210 6F9759 5F8558 6F7214 6F9760 through 5F8576 6F7218 6F9765 5F8577 6F7501 6F9846 5F8581 through 6F7502 6F9853 5F8584 6F7504 6F9861 6F7949 6F9866 6F8168 7F0156 6F8198 7F0480 7F0556 Pratt & Whitney Aircraft telegram PSE/RS/1-3-10-1 covers this same subject. Compliance required as indicated. To preclude twelfth stage compressor rotor disc failure as the result of suspected material deficiency, accomplish the following: 1. For all the previously listed serial number twelfth stage compressor rotor discs: A. With 18,000 hours or more in service within the next 50 hours in service after the effective date of this AD, replace the suspect serial number disc. B. With 18,000 hours or less in service prior to the accumulation of 18,050 hours in service, replace the suspect serial number disc. 2. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time. Amendment 39-1168 was effective March 12, 1971. This amendment 39-1211 is effective May 19, 1971 and was effective for all recipients of the telegram dated March 12, 1971 which contained this amendment. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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