AD 59-20-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 707-100 Long Body | BOEING 707-100 Series Aircraft |
| aircraft | The Boeing Company | 707-100B Long Body | BOEING 707-100 Series Aircraft |
| aircraft | The Boeing Company | 707-100B Short Body | BOEING 707-100 Series Aircraft |
Unsafe Condition
Failures of the welded flanges at each end of the turbocompressor bleed duct mounted on the high pressure bleed port of the engine have caused damage to surrounding structure due to excessive pressure and temperature in the cowl and required engine shutdown due to high EGT and low EPR.
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Required Actions
Add an additional fillet weld to the external side of the three flanges on the turbocompressor engine bleed duct assembly and strengthen the existing boss weld by welding gussets to both the boss and duct in accordance with Boeing Service Bulletin No. 543.
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Compliance Time
November 15, 1959
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Affected Aircraft
Boeing 707-100 series aircraft with serial numbers 17586 through 17591, 17609 through 17612, 17628 through 17652, 17658 through 17672, 17696 through 17702, 17925 through 17927.
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Federal Register Abstract
Turbocompressor Engine Bleed Duct Assembly
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_59-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: BOEING 707-100 Series Aircraft Subject: Turbocompressor Engine Bleed Duct Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: 707-100 Long Body | 707-100B Long Body | 707-100B Short Body Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 59-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-20-04 SUBJECT HEADING: BOEING 707-100 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-20-04 BOEING: Applies to the following 707-100 series aircraft only: Serial Numbers 17586 through 17591, 17609 through 17612, 17628 through 17652, 17658 through 17672, 17696 through 17702, 17925 through 17927. Compliance required not later than November 15, 1959. There have been failures of the welded flanges located at each end of the turbocompressor bleed duct mounted on the high pressure bleed port of the engine. These failures have caused damage to the surrounding structure due to excessive pressure and temperature in the cowl and also required engine shutdown due to high EGT and low EPR. Therefore, the following modification(s) shall be accomplished as indicated: (a) An additional filetweld shall be added to the external side of the three flanges on the turbocompressor engine bleed duct assembly. (Each pod utilizing a turbocompressor.) (b) The existing boss weld on the turbocompressor engine bleed duct shall be strengthened by welding gussets to both the boss and duct. These gussets are to be fabricated in accordance with Boeing Service Bulletin No. 543 figure 2. NOTE: The above modification(s) are included in Boeing Airplane Company Service Bulletin No. 543 dated August 14, 1959. FOOTER:
Document Text
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AD Final Rules - DRS_59-20-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 59-20-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: BOEING 707-100 Series Aircraft Subject: Turbocompressor Engine Bleed Duct Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: 707-100 Long Body | 707-100B Long Body | 707-100B Short Body Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 59-20-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 59-20-04 SUBJECT HEADING: BOEING 707-100 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 59-20-04 BOEING: Applies to the following 707-100 series aircraft only: Serial Numbers 17586 through 17591, 17609 through 17612, 17628 through 17652, 17658 through 17672, 17696 through 17702, 17925 through 17927. Compliance required not later than November 15, 1959. There have been failures of the welded flanges located at each end of the turbocompressor bleed duct mounted on the high pressure bleed port of the engine. These failures have caused damage to the surrounding structure due to excessive pressure and temperature in the cowl and also required engine shutdown due to high EGT and low EPR. Therefore, the following modification(s) shall be accomplished as indicated: (a) An additional filetweld shall be added to the external side of the three flanges on the turbocompressor engine bleed duct assembly. (Each pod utilizing a turbocompressor.) (b) The existing boss weld on the turbocompressor engine bleed duct shall be strengthened by welding gussets to both the boss and duct. These gussets are to be fabricated in accordance with Boeing Service Bulletin No. 543 figure 2. NOTE: The above modification(s) are included in Boeing Airplane Company Service Bulletin No. 543 dated August 14, 1959. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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