AD 70-25-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT8D-1 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-11 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-15 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-15A | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-17 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-17A | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-17AR | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-17R | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-1A | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-1B | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-209 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-217 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-217A | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-217C | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-219 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-5 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-7 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-7A | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-7B | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-9 | PRATT & WHITNEY Model JT8D Series Engines |
| engine | Pratt & Whitney Division | JT8D-9A | PRATT & WHITNEY Model JT8D Series Engines |
Unsafe Condition
Seventh stage compressor rotor disc failures 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 discs with specific cycle thresholds: within 30 cycles for 2700+ cycles in service, within 100 cycles but before 2730 for 2300-2700 cycles, within 300 cycles but before 2400 for 2000-2300 cycles, and before 2300 cycles for less than 2000 cycles.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the specified cycle thresholds as outlined in the directive.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney JT8D series engines with Part Number 500507 seventh stage compressor rotor disc serial numbers listed in Service Bulletin No. 2817, Rev. No. 1.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Seventh Stage Compressor Rotor Disc
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_70-25-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 70-25-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT8D Series Engines Subject: Seventh Stage Compressor Rotor Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/15/1970 Make: Pratt & Whitney Division Model: JT8D-1 | JT8D-11 | JT8D-15 | JT8D-15A | JT8D-17 | JT8D-17A | JT8D-17AR | JT8D-17R | JT8D-1A | JT8D-1...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: 70-25-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1084 AD NUMBER: 70-25-08 SUBJECT HEADING: PRATT & WHITNEY Model JT8D Series Engines ACTION: SUMMARY: DATES: Effective December 15, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 70-25-08 PRATT & WHITNEY: Amdt. 39-1084. Applies to all Pratt & Whitney aircraft JT8D series turbofan engines which incorporate Part Number 500507 seventh stage compressor rotor disc with serial numbers listed in Pratt & Whitney Service Bulletin No. 2817, Rev. No. 1, dated 18 September 1970. Compliance required as indicated after the effective date of this airworthiness directive unless already accomplished. To preclude seventh stage compressor rotor disc failures as the result of suspected material deficiency, accomplish the following: 1. Replace discs with 2700 cycles or more in service within the next 30 cycles in service. 2. Replace discs with 2300 cycles, but less than 2700 cycles in service, within the next 100 cycles in service, but prior to accumulation of 2730 cycles. 3. Replace discs with 2000 cycles, but less than 2300 cycles in service, within the next 300 cycles in service, but prior to the accumulation of 2400 cycles. 4. Replace discs with less than 2000 cycles in service prior to the accumulation of 2300 cycles. The manufacturer's Service Bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552 (a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request from Pratt & Whitney Aircraft Division of United Aircraft Corporation, East Hartford, Conn. This document may also be examined at the FAA, Eastern Region, Federal Building, J. F. Kennedy International Airport, Jamaica, N.Y., at the FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and in the Eastern Region. This amendment is effective December 15, 1970 and was effective October 2, 1970, for all recipients of the telegram dated October 2, 1970, which contained this amendment. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_70-25-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 70-25-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Model JT8D Series Engines Subject: Seventh Stage Compressor Rotor Disc Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/15/1970 Make: Pratt & Whitney Division Model: JT8D-1 | JT8D-11 | JT8D-15 | JT8D-15A | JT8D-17 | JT8D-17A | JT8D-17AR | JT8D-17R | JT8D-1A | JT8D-1...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: 70-25-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1084 AD NUMBER: 70-25-08 SUBJECT HEADING: PRATT & WHITNEY Model JT8D Series Engines ACTION: SUMMARY: DATES: Effective December 15, 1970. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 70-25-08 PRATT & WHITNEY: Amdt. 39-1084. Applies to all Pratt & Whitney aircraft JT8D series turbofan engines which incorporate Part Number 500507 seventh stage compressor rotor disc with serial numbers listed in Pratt & Whitney Service Bulletin No. 2817, Rev. No. 1, dated 18 September 1970. Compliance required as indicated after the effective date of this airworthiness directive unless already accomplished. To preclude seventh stage compressor rotor disc failures as the result of suspected material deficiency, accomplish the following: 1. Replace discs with 2700 cycles or more in service within the next 30 cycles in service. 2. Replace discs with 2300 cycles, but less than 2700 cycles in service, within the next 100 cycles in service, but prior to accumulation of 2730 cycles. 3. Replace discs with 2000 cycles, but less than 2300 cycles in service, within the next 300 cycles in service, but prior to the accumulation of 2400 cycles. 4. Replace discs with less than 2000 cycles in service prior to the accumulation of 2300 cycles. The manufacturer's Service Bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552 (a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request from Pratt & Whitney Aircraft Division of United Aircraft Corporation, East Hartford, Conn. This document may also be examined at the FAA, Eastern Region, Federal Building, J. F. Kennedy International Airport, Jamaica, N.Y., at the FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and in the Eastern Region. This amendment is effective December 15, 1970 and was effective October 2, 1970, for all recipients of the telegram dated October 2, 1970, which contained this amendment. 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.