AD 76-01-08

final rule

PRATT & WHITNEY AIRCRAFT Model JT4A Engines

AD Number
76-01-08
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 JT4A-10 PRATT & WHITNEY AIRCRAFT Model JT4A Engines
engine Pratt & Whitney Division JT4A-11 PRATT & WHITNEY AIRCRAFT Model JT4A Engines
engine Pratt & Whitney Division JT4A-12 PRATT & WHITNEY AIRCRAFT Model JT4A Engines
engine Pratt & Whitney Division JT4A-3 PRATT & WHITNEY AIRCRAFT Model JT4A Engines
engine Pratt & Whitney Division JT4A-5 PRATT & WHITNEY AIRCRAFT Model JT4A Engines
engine Pratt & Whitney Division JT4A-9 PRATT & WHITNEY AIRCRAFT Model JT4A Engines

Unsafe Condition

Tenth stage compressor blade failure resulting in case penetration.

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

Required Actions

Shotpeen the tenth stage compressor blades in accordance with JT4A Overhaul Manual, P/N 384887, Section 72-36-1, and apply antigalling compound as per TR 72-617 of the same manual. Compliance must follow specified intervals based on time in service since last shotpeening or January 28, 1976.

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

Compliance Time

Within 4000 hours time in service since last shotpeening to 6A intensity or within 2000 hours time in service since January 28, 1976, whichever is later, and every 4000 hours thereafter. For blades shotpeened to 11A intensity: within 6000 hours since last shotpeening or 2000 hours after January 28, 1976, whichever is later, and every 6000 hours thereafter. Blades never shotpeened must comply within 2000 hours after January 28, 1976, then follow paragraphs 1 and 2 intervals.

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

Affected Aircraft

Pratt & Whitney Aircraft Model JT4A engines with tenth stage compressor blades P/N 499710 or P/N 310010.

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

Federal Register Abstract

Tenth Stage Compressor Blade

Applicability Source Text

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AD Final Rules - DRS_76-01-08.html
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AD Number:
76-01-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
PRATT & WHITNEY AIRCRAFT Model JT4A Engines
Subject:
Tenth Stage Compressor Blade
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/20/1976
Make:
Pratt & Whitney Division
Model:
JT4A-10 | JT4A-11 | JT4A-12 | JT4A-3 | JT4A-5 | JT4A-9
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: 76-01-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2603

AD NUMBER:   76-01-08

SUBJECT HEADING:   PRATT & WHITNEY AIRCRAFT Model JT4A Engines

ACTION:  

SUMMARY:  

DATES:   Effective May 20, 1976.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
76-01-08 PRATT & WHITNEY AIRCRAFT: Amendment 39-2492 as amended by Amendment 39-2603. Applies to all Pratt & Whitney Model JT4A turbojet engines containing tenth stage compressor blades, P/N 499710 and P/N 310010.

To prevent possible tenth stage compressor blade failure resulting in case penetration, shotpeen the blades in accordance with JT4A Overhaul Manual, P/N 384887, Section 72-36-1, and apply antigalling compound in accordance with TR 72-617, of JT4A Overhaul Manual P/N 384887, in accordance with the following schedule:

1. Within 4000 hours time in service since the last shotpeening to 6A intensity or within 2000 hours time in service since January 28, 1976, whichever is later, and every 4000 hours time in service thereafter.

2. Within 6000 hours time in service since the last shotpeening to 11A intensity or 2000 hours after January 28, 1976, whichever is later and every 6000 hours time in service thereafter.

3. Blades that have never been shotpeened must be shotpeened within 2000 hours time in service since January 28, 1976, and are subsequently subject to the repetitive shotpeening requirements of paragraphs 1 and 2.

Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the repetitive shotpeen 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 that operator.

The manufacturer's specifications and procedures identified and described in this directive are 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 these documents from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Division of United Aircraft Corporation, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at 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 at New England Region.

Amendment 39-2492 became effective on January 28, 1976.

This amendment 39-2603 becomes effective May 20, 1976.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_76-01-08.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
76-01-08
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
PRATT & WHITNEY AIRCRAFT Model JT4A Engines
Subject:
Tenth Stage Compressor Blade
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/20/1976
Make:
Pratt & Whitney Division
Model:
JT4A-10 | JT4A-11 | JT4A-12 | JT4A-3 | JT4A-5 | JT4A-9
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: 76-01-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2603

AD NUMBER:   76-01-08

SUBJECT HEADING:   PRATT & WHITNEY AIRCRAFT Model JT4A Engines

ACTION:  

SUMMARY:  

DATES:   Effective May 20, 1976.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
76-01-08 PRATT & WHITNEY AIRCRAFT: Amendment 39-2492 as amended by Amendment 39-2603. Applies to all Pratt & Whitney Model JT4A turbojet engines containing tenth stage compressor blades, P/N 499710 and P/N 310010.

To prevent possible tenth stage compressor blade failure resulting in case penetration, shotpeen the blades in accordance with JT4A Overhaul Manual, P/N 384887, Section 72-36-1, and apply antigalling compound in accordance with TR 72-617, of JT4A Overhaul Manual P/N 384887, in accordance with the following schedule:

1. Within 4000 hours time in service since the last shotpeening to 6A intensity or within 2000 hours time in service since January 28, 1976, whichever is later, and every 4000 hours time in service thereafter.

2. Within 6000 hours time in service since the last shotpeening to 11A intensity or 2000 hours after January 28, 1976, whichever is later and every 6000 hours time in service thereafter.

3. Blades that have never been shotpeened must be shotpeened within 2000 hours time in service since January 28, 1976, and are subsequently subject to the repetitive shotpeening requirements of paragraphs 1 and 2.

Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the repetitive shotpeen 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 that operator.

The manufacturer's specifications and procedures identified and described in this directive are 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 these documents from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Division of United Aircraft Corporation, 400 Main Street, East Hartford, Connecticut 06108. These documents may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and at 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 at New England Region.

Amendment 39-2492 became effective on January 28, 1976.

This amendment 39-2603 becomes effective May 20, 1976.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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