AD 73-16-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT9D-20 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-20J | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-3A | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-59A | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-70A | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7A | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7AH | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7F | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7H | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7J | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7Q | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7Q3 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4D | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4D1 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4E | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4E1 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4E4 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4G2 | PRATT & WHITNEY Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7R4H1 | PRATT & WHITNEY Model JT9D Engines |
Unsafe Condition
Failure of fourth and fifth stage turbine discs due to reduced life limits below previously approved figures.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove from service fourth and fifth stage turbine discs prior to reaching the revised life limit of 4000 cycles or within the next 25 cycles in service after the effective date of this AD, whichever comes later.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 25 cycles in service after the effective date of this airworthiness directive whichever comes later
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Division JT9D engines with fourth and fifth stage turbine discs P/N 646304, 694804, 618305, and 705905
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Fourth and Fifth Stage Turbine Discs
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_73-16-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-16-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT9D Engines Subject: Fourth and Fifth Stage Turbine Discs Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 08/15/1973 Make: Pratt & Whitney Division Model: JT9D-20 | JT9D-20J | JT9D-3A | JT9D-59A | JT9D-7 | JT9D-70A | JT9D-7A | JT9D-7AH | JT9D-7F | JT9D-7H...Show more 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: 73-16-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1698 AD NUMBER: 73-16-05 SUBJECT HEADING: PRATT & WHITNEY Model JT9D Engines ACTION: SUMMARY: DATES: Effective August 15, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-16-05 PRATT & WHITNEY: Amdt. 39-1698. Applies to all Pratt and Whitney Aircraft JT9D turbofan engines containing fourth and fifth stage turbine discs, P/N 646304, 694804, 618305, and 705905. Compliance required as indicated. To prevent possible failure of fourth and fifth stage turbine discs, the life limits on these parts have been reduced below the figures currently approved. Unless already accomplished, remove from service fourth and fifth stage turbine discs prior to reaching the revised life limit listed below or within the next 25 cycles in service after the effective date of this airworthiness directive whichever comes later. Disc Part Number Previous Life Limit Cycles Revised Life Limit Cycles 646304 8000 4000 694804 8000 4000 618305 8000 4000 705905 8000 4000 (Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the compliance time). NOTE: (Pratt and Whitney Service Bulletin No. 3785 pertains to this subject). This amendment becomes effective August 15, 1973. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_73-16-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-16-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT9D Engines Subject: Fourth and Fifth Stage Turbine Discs Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 08/15/1973 Make: Pratt & Whitney Division Model: JT9D-20 | JT9D-20J | JT9D-3A | JT9D-59A | JT9D-7 | JT9D-70A | JT9D-7A | JT9D-7AH | JT9D-7F | JT9D-7H...Show more 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: 73-16-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1698 AD NUMBER: 73-16-05 SUBJECT HEADING: PRATT & WHITNEY Model JT9D Engines ACTION: SUMMARY: DATES: Effective August 15, 1973. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-16-05 PRATT & WHITNEY: Amdt. 39-1698. Applies to all Pratt and Whitney Aircraft JT9D turbofan engines containing fourth and fifth stage turbine discs, P/N 646304, 694804, 618305, and 705905. Compliance required as indicated. To prevent possible failure of fourth and fifth stage turbine discs, the life limits on these parts have been reduced below the figures currently approved. Unless already accomplished, remove from service fourth and fifth stage turbine discs prior to reaching the revised life limit listed below or within the next 25 cycles in service after the effective date of this airworthiness directive whichever comes later. Disc Part Number Previous Life Limit Cycles Revised Life Limit Cycles 646304 8000 4000 694804 8000 4000 618305 8000 4000 705905 8000 4000 (Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the compliance time). NOTE: (Pratt and Whitney Service Bulletin No. 3785 pertains to this subject). This amendment becomes effective August 15, 1973. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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