AD 77-01-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT9D-20 | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-3A | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-7 | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-7A | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-7AH | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-7F | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
| engine | Pratt & Whitney Division | JT9D-7H | PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines |
Unsafe Condition
Cracking and possible failure of fifth stage turbine hubs due to cyclic life limits exceeding approved figures.
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Required Actions
Remove from service fifth stage turbine hubs prior to reaching the revised life limits (listed by part number) or within the next 25 cycles after the AD's effective date, whichever is later. Operators may request FAA approval to adjust the 25-cycle compliance interval with substantiating data.
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Compliance Time
within the next 25 cycles in service after the effective date of this AD
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Affected Aircraft
Pratt & Whitney Aircraft JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 engines with fifth stage turbine hubs P/N 704705, 714905, 718905, 719205, and 726805.
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Federal Register Abstract
Fifth Stage Turbine Hubs
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_77-01-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 77-01-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines Subject: Fifth Stage Turbine Hubs Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: JT9D-20 | JT9D-3A | JT9D-7 | JT9D-7A | JT9D-7AH | JT9D-7F | JT9D-7H 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: 77-01-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2807 AD NUMBER: 77-01-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 77-01-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2807. Applies to all Pratt & Whitney Aircraft JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 turbofan engines containing fifth stage turbine hubs, P/N 704705, 714905, 718905, 719205, and 726805. Compliance required as indicated. To prevent cracking and possible failure of fifth stage turbine hubs, the cyclic life limits on these parts have been reduced below the figures currently approved. Unless already accomplished, remove from service fifth stage turbine hubs prior to reaching the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever is later. Hub Part Number Previous Life Limit (Cycles) Revised Life Limit (Cycles) 704705 15,000 7,000 714905 15,000 6,000 718905 8,000 5,000 719205 8,000 5,000 726805 8,000 5,000 Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering & Manufacturing Branch, New England Region, may adjust the 25 cycle compliance interval to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. (NOTE: Pratt & Whitney Alert Service Bulletin No. 4671 pertains to this subject.) This amendment becomes effective upon publication in the Federal Register. FOOTER:
Document Text
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AD Final Rules - DRS_77-01-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 77-01-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines Subject: Fifth Stage Turbine Hubs Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: JT9D-20 | JT9D-3A | JT9D-7 | JT9D-7A | JT9D-7AH | JT9D-7F | JT9D-7H 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: 77-01-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2807 AD NUMBER: 77-01-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Models JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 77-01-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2807. Applies to all Pratt & Whitney Aircraft JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 turbofan engines containing fifth stage turbine hubs, P/N 704705, 714905, 718905, 719205, and 726805. Compliance required as indicated. To prevent cracking and possible failure of fifth stage turbine hubs, the cyclic life limits on these parts have been reduced below the figures currently approved. Unless already accomplished, remove from service fifth stage turbine hubs prior to reaching the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever is later. Hub Part Number Previous Life Limit (Cycles) Revised Life Limit (Cycles) 704705 15,000 7,000 714905 15,000 6,000 718905 8,000 5,000 719205 8,000 5,000 726805 8,000 5,000 Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering & Manufacturing Branch, New England Region, may adjust the 25 cycle compliance interval to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. (NOTE: Pratt & Whitney Alert Service Bulletin No. 4671 pertains to this subject.) This amendment becomes effective upon publication in the Federal Register. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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