AD 73-07-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT3D-1 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC6 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC7 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines |
| engine | Pratt & Whitney Division | JT3D-3 | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines |
| engine | Pratt & Whitney Division | JT3D-3B | PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines |
Unsafe Condition
Loosening of fuel control to fuel pump return tube elbow P/N 424790 and jam nut P/N 217477 could cause fuel leakage due to worn mating threads on their loaded sides.
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Required Actions
Check jam nut torque value. If torque is below 285 in-lbs, break connection and examine mating threads for wear. Replace worn parts with new/serviceable parts or per Service Bulletin 1511 Rev 4 if threads are worn. Remake fitting per Overhaul Manual if threads are not worn.
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Compliance Time
within the next 500 hours time in service after the effective date of this AD and every 1000 hours in service thereafter
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Affected Aircraft
Pratt & Whitney JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3, and JT3D-3B engines with fuel control to fuel return line elbow P/N 424790 and jam nut P/N 217477
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Federal Register Abstract
Fuel Control To Fuel Return Line Elbow and Jam Nut
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_73-07-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-07-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines Subject: Fuel Control To Fuel Return Line Elbow and Jam Nut Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: JT3D-1 | JT3D-1-MC6 | JT3D-1-MC7 | JT3D-3 | JT3D-3B Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 73-07-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1630 AD NUMBER: 73-07-08 SUBJECT HEADING: PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-07-08 PRATT & WHITNEY: Amendment 39-1616 as amended by Amendment 39-1630. Applies to all Pratt & Whitney JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B model engines containing fuel control to fuel return line elbow P/N 424790 and jam nut P/N 217477. Compliance required within the next 500 hours time in service after the effective date of this AD and every 1000 hours in service thereafter, or until modified in accordance with the service bulletin referenced in paragraph (b)(2) or equivalent method approved by the Chief, Engineering and Manufacturing Branch, New England Region. To prevent the possibility of fuel leakage due to loosening of fuel control to fuel pump return tube elbow P/N 424790, and jam nut P/N 217477, check jam nut torque value. (a) If found to be a minimum of 285 in-lbs., continue in service operation. (b) If the jam nut is found to be less than 285 in-lbs., break the connection and examine the mating threads of the elbow P/N 424790 and fuel control cover P/N 704972-1 on their loaded sides for wear. NOTE: The loaded side will be on the fuel side (inside) rather than the air side (outside) of the cover. (1) If the threads are not worn remake the fitting according to the instructions given in the Overhaul Manual, P/N 411568, Section 72-00, Fits and Clearances. (2) If the threads of the elbow. P/N 424790, or fuel control cover P/N 704972-1, are found worn replace with new or serviceable parts of same part number or with P/N 483848 elbow and associated hardware in accordance with Pratt & Whitney Service Bulletin No. 1511 Revision 4, dated June 20, 1969, or later FAA approved revision. (c) Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust repetitive inspection intervals specified in this AD. Amendment 39-1616 became effective April 11, 1973. This amendment 39-1630 becomes effective upon publication in the Federal Register. FOOTER:
Document Text
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AD Final Rules - DRS_73-07-08.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 73-07-08 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines Subject: Fuel Control To Fuel Return Line Elbow and Jam Nut Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: JT3D-1 | JT3D-1-MC6 | JT3D-1-MC7 | JT3D-3 | JT3D-3B 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: 73-07-08 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1630 AD NUMBER: 73-07-08 SUBJECT HEADING: PRATT & WHITNEY Models JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 73-07-08 PRATT & WHITNEY: Amendment 39-1616 as amended by Amendment 39-1630. Applies to all Pratt & Whitney JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-3 and JT3D-3B model engines containing fuel control to fuel return line elbow P/N 424790 and jam nut P/N 217477. Compliance required within the next 500 hours time in service after the effective date of this AD and every 1000 hours in service thereafter, or until modified in accordance with the service bulletin referenced in paragraph (b)(2) or equivalent method approved by the Chief, Engineering and Manufacturing Branch, New England Region. To prevent the possibility of fuel leakage due to loosening of fuel control to fuel pump return tube elbow P/N 424790, and jam nut P/N 217477, check jam nut torque value. (a) If found to be a minimum of 285 in-lbs., continue in service operation. (b) If the jam nut is found to be less than 285 in-lbs., break the connection and examine the mating threads of the elbow P/N 424790 and fuel control cover P/N 704972-1 on their loaded sides for wear. NOTE: The loaded side will be on the fuel side (inside) rather than the air side (outside) of the cover. (1) If the threads are not worn remake the fitting according to the instructions given in the Overhaul Manual, P/N 411568, Section 72-00, Fits and Clearances. (2) If the threads of the elbow. P/N 424790, or fuel control cover P/N 704972-1, are found worn replace with new or serviceable parts of same part number or with P/N 483848 elbow and associated hardware in accordance with Pratt & Whitney Service Bulletin No. 1511 Revision 4, dated June 20, 1969, or later FAA approved revision. (c) Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust repetitive inspection intervals specified in this AD. Amendment 39-1616 became effective April 11, 1973. This amendment 39-1630 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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