AD 62-17-06

final rule

PRATT & WHITNEY Model JT3C-12 Engines

AD Number
62-17-06
Status
final_rule
Effective Date
Product Category
engine
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
engine Pratt & Whitney Division JT3C-12 PRATT & WHITNEY Model JT3C-12 Engines

Unsafe Condition

Fatigue cracking in the rear face of the P/N 359708 eighth stage compressor rotor disc.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect discs using an American Cystoscope Markers, Inc. Model B-175-AS-15 or FAA approved equivalent viewing instrument inserted through an inspection hole in the compressor case and eighth stage stator shroud. Reinspect every 90 hours' time in service after the last inspection. Remove and replace cracked discs. Remove all discs after 4,800 hours' time in service.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Compliance required as indicated.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

All Pratt & Whitney Model JT3C-12 Turbojet Engines.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Compressor Rotor Disc

Applicability Source Text

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AD Final Rules - DRS_62-17-06.html
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AD Number:
62-17-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
PRATT & WHITNEY Model JT3C-12 Engines
Subject:
Compressor Rotor Disc
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Pratt & Whitney Division
Model:
JT3C-12
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Superseded AD: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Superseded By: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: 62-17-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   62-17-06

SUBJECT HEADING:   PRATT & WHITNEY Model JT3C-12 Engines

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
62-17-06 PRATT & WHITNEY: Amdt. 470 Part 507 Federal Register August 1, 1962. Applies to All JT3C-12 Turbojet Engines.

Compliance required as indicated.

To preclude fatigue cracking in the rear face of the P/N 359708 eighth stage compressor rotor disc, accomplish the following:

(a) For discs previously inspected by the procedure described in paragraph (c), reinspect in accordance with paragraph (c) every 90 hours' time in service from the last inspection.

(b) For discs not previously inspected by the procedure described in paragraph (c), inspect in accordance with paragraph (c) as follows:

(1) Inspect discs with 1,000 or more hours' time in service within the next 90 hours' time in service and every 90 hours' time in service thereafter.

(2) Inspect discs with less than 1,000 hours' time in service prior to the accumulation of 1,090 hours' time in service and every 90 hours' time in service thereafter.

(c) Incorporate an inspection hole and plug in the compressor case and eighth stage stator shroud in accordance with Pratt & Whitney Aircraft letter dated June 21, 1962, and its attached sketch number L-53852. Using an American Cystoscope Markers, Inc. Model B-175-AS-15 or FAA approved equivalent viewing instrument inserted through this hole, inspect each eighth stage compressor rotor disc rear blade dovetail area and the entire circumferential area of the eighth stage disc spacer for possible cracks. If any crack indications are found, remove the engine prior to further flight and disassemble for confirmation of the indications. Replace cracked discs.

(d) Remove all eighth stage compressor rotor discs P/N 359708 from further service after 4,800 hours' time in service.

(e) Upon request of the operator, an FAA Maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

(Pratt & Whitney Aircraft telegraphic message dated June 13, 1962, to Eastern Air Lines and Pratt & Whitney Aircraft letter dated June 21, 1962, and attached sketch L-53852 to Eastern Air Lines covers the same subject.)

This directive effective August 1, 1962.

Revised February 20, 1963.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_62-17-06.html
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 Feedback
Details
AD Number:
62-17-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
PRATT & WHITNEY Model JT3C-12 Engines
Subject:
Compressor Rotor Disc
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Pratt & Whitney Division
Model:
JT3C-12
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: 62-17-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   62-17-06

SUBJECT HEADING:   PRATT & WHITNEY Model JT3C-12 Engines

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
62-17-06 PRATT & WHITNEY: Amdt. 470 Part 507 Federal Register August 1, 1962. Applies to All JT3C-12 Turbojet Engines.

Compliance required as indicated.

To preclude fatigue cracking in the rear face of the P/N 359708 eighth stage compressor rotor disc, accomplish the following:

(a) For discs previously inspected by the procedure described in paragraph (c), reinspect in accordance with paragraph (c) every 90 hours' time in service from the last inspection.

(b) For discs not previously inspected by the procedure described in paragraph (c), inspect in accordance with paragraph (c) as follows:

(1) Inspect discs with 1,000 or more hours' time in service within the next 90 hours' time in service and every 90 hours' time in service thereafter.

(2) Inspect discs with less than 1,000 hours' time in service prior to the accumulation of 1,090 hours' time in service and every 90 hours' time in service thereafter.

(c) Incorporate an inspection hole and plug in the compressor case and eighth stage stator shroud in accordance with Pratt & Whitney Aircraft letter dated June 21, 1962, and its attached sketch number L-53852. Using an American Cystoscope Markers, Inc. Model B-175-AS-15 or FAA approved equivalent viewing instrument inserted through this hole, inspect each eighth stage compressor rotor disc rear blade dovetail area and the entire circumferential area of the eighth stage disc spacer for possible cracks. If any crack indications are found, remove the engine prior to further flight and disassemble for confirmation of the indications. Replace cracked discs.

(d) Remove all eighth stage compressor rotor discs P/N 359708 from further service after 4,800 hours' time in service.

(e) Upon request of the operator, an FAA Maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

(Pratt & Whitney Aircraft telegraphic message dated June 13, 1962, to Eastern Air Lines and Pratt & Whitney Aircraft letter dated June 21, 1962, and attached sketch L-53852 to Eastern Air Lines covers the same subject.)

This directive effective August 1, 1962.

Revised February 20, 1963.

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.