AD 75-04-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT3D-3 | PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines |
| engine | Pratt & Whitney Division | JT3D-3B | PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines |
| engine | Pratt & Whitney Division | JT3D-7 | PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines |
Unsafe Condition
The tenth stage compressor disk, P/N 701810, may exceed its cyclic life limit, leading to potential failure of the disk.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove from service the tenth stage compressor disk prior to exceeding the revised life limits (25,000 cycles for JT3D-3 and -3B, 23,000 cycles for JT3D-7) or within the next 25 cycles after the AD's effective date, whichever comes later. If a disk was used in multiple engine models, it must be limited to the lowest cyclic life limit among those models.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
prior to exceeding the revised life limit listed below 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.
Affected Aircraft
Pratt & Whitney Aircraft JT3D-3, JT3D-3B, and JT3D-7 turbofan engines containing tenth stage compressor disk, P/N 701810
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Tenth Stage Compressor Disk
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_75-04-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-04-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines Subject: Tenth Stage Compressor Disk Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/19/1975 Make: Pratt & Whitney Division Model: JT3D-3 | JT3D-3B | JT3D-7 Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 75-04-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2084 AD NUMBER: 75-04-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines ACTION: SUMMARY: DATES: Effective February 19, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-04-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2084. Applies to all Pratt & Whitney Aircraft JT3D-3, JT3D-3B, and JT3D-7 turbofan engines containing tenth stage compressor disk, P/N 701810. Compliance required as indicated. To ensure adequate life limit margin for tenth stage compressor disk, P/N 701810, the cyclic life limits on these disks have been reduced below the figures currently approved. Unless already accomplished, remove from service the tenth stage compressor disk prior to exceeding the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever comes later. Engine Model Previous Life Limit (Cycles) Revised Life Limit (Cycles) JT3D-3 30,000 25,000 JT3D-3B 30,000 25,000 JT3D-7 25,000 23,000 If a disk has been used in more than one engine model, the disk is limited to the lowest cyclic life permitted for the engine models in which it has been exposed. This amendment becomes effective February 19, 1975. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_75-04-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-04-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines Subject: Tenth Stage Compressor Disk Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 02/19/1975 Make: Pratt & Whitney Division Model: JT3D-3 | JT3D-3B | JT3D-7 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: 75-04-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2084 AD NUMBER: 75-04-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Models JT3D-3, JT3D-3B, and JT3D-7 Engines ACTION: SUMMARY: DATES: Effective February 19, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-04-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2084. Applies to all Pratt & Whitney Aircraft JT3D-3, JT3D-3B, and JT3D-7 turbofan engines containing tenth stage compressor disk, P/N 701810. Compliance required as indicated. To ensure adequate life limit margin for tenth stage compressor disk, P/N 701810, the cyclic life limits on these disks have been reduced below the figures currently approved. Unless already accomplished, remove from service the tenth stage compressor disk prior to exceeding the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever comes later. Engine Model Previous Life Limit (Cycles) Revised Life Limit (Cycles) JT3D-3 30,000 25,000 JT3D-3B 30,000 25,000 JT3D-7 25,000 23,000 If a disk has been used in more than one engine model, the disk is limited to the lowest cyclic life permitted for the engine models in which it has been exposed. This amendment becomes effective February 19, 1975. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
Related Airworthiness Directives
99-01-08
final ruleAirworthiness Directives; Pratt & Whitney JT8D and JT3D Series Turbofan Engines
Unsafe Condition: Stage 7 through Stage 15 High-Pressure Compressor (HPC) Disks
96-23-10
final ruleAirworthiness Directives; Pratt & Whitney JT3D Series Turbofan Engines
Unsafe Condition: Steel high pressure compressor (HPC) disk failure due to corrosion could result in an uncontained engine failure and damage to the aircraft.
89-22-07
final rulePRATT & WHITNEY Models JT3D-3B and JT3D-7 Engines
Unsafe Condition: The engines may have compromised structural integrity and certificated performance capabilities due to potential defects or improper maintenance during overhaul at Jet Power, Inc.
82-14-02
final rulePRATT & WHITNEY AIRCRAFT Model JT3D Engines
Unsafe Condition: Cracks in third stage turbine disks (P/Ns 418903, 438903, and 675803) could result in fracture of the third stage turbine disk and an uncontained third stage turbine disk failure.