AD 47-35-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Holmes, Douglas W. | R-4B (Army) | Airworthiness Directives; Sikorsky Model R44-B Helicopter |
Unsafe Condition
Failure of the main rotor links due to lack of lubrication causing loss of flight control.
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Required Actions
Re-work main rotor links (P/N VS 36181) by removing and inspecting for cracks, machining oil grooves, replacing bearings with P/N AT-16-OH if original bearings are P/N AT-16, and following specified cleaning and inspection methods.
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Compliance Time
before November 15, 1947
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Affected Aircraft
Sikorsky Model R4-B Helicopter Serial Numbers 43-46500 to 43-46502 and 43-46504 to 43-46539 Inclusive.
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Federal Register Abstract
Main Rotor Links Rework
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-35-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-35-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model R44-B Helicopter Subject: Main Rotor Links Rework Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Holmes, Douglas W. Model: R-4B (Army) Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-35-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-35-01 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model R44-B Helicopter ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-35-01 SIKORSKY: (Was Mandatory Note 1 of AD-7L-1.) Applies to Model R4-B Helicopter Serial Numbers 43-46500 to 43-46502 and 43-46504 to 43-46539 Inclusive. Compliance required before November 15, 1947. To reduce the possibility of loss of flight control due to failure of the main rotor links from lack of lubrication, the links should be reworked in accordance with the following instructions. This change involves the removal and inspection of main rotor link, P/N VS 36181 and machining of oil grooves. 1. Strip paint from the subject links with a paint remover or lacquer thinner, Specification No. AN-TT-T-256 or equivalent. Do not use scraper or wire brush on links, because small cracks may be filled in and covered. 2. Visually inspect main rotor links, P/N VS 36181 by one of the following methods for cracks around link pin hole and longitudinally along what was the flash line in original forging. (See Figure 1.) If cracks are present, links should be scrapped. AD 47-35-01 (a) Visual inspection after re-anodizing; or (b) By caustic etching; or (c) By an approved fluorescent-black light method. 3. Machine oil grooves. (See Figure 1.) 4. Remove burrs and clean after machining. 5. Inspect the two bearings removed from each of the three subject links. (a) If bearings removed are P/N AT-16, replace with P/N AT-16-OH bearings on assembly. (Bearing AT-16-OH is an AT-16 bearing with an oil hole added to its outer race.) (b) If bearings removed are P/N AT-16-OH and retainer washers are damaged or show evidence of foreign matter, they are to be replaced. (Sikorsky Service Bulletin R-4B No. 10 and Army T. O. 01-230HA-15 also cover this same subject.) FOOTER:
Document Text
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AD Final Rules - DRS_47-35-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-35-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model R44-B Helicopter Subject: Main Rotor Links Rework Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Holmes, Douglas W. Model: R-4B (Army) Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 47-35-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-35-01 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model R44-B Helicopter ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-35-01 SIKORSKY: (Was Mandatory Note 1 of AD-7L-1.) Applies to Model R4-B Helicopter Serial Numbers 43-46500 to 43-46502 and 43-46504 to 43-46539 Inclusive. Compliance required before November 15, 1947. To reduce the possibility of loss of flight control due to failure of the main rotor links from lack of lubrication, the links should be reworked in accordance with the following instructions. This change involves the removal and inspection of main rotor link, P/N VS 36181 and machining of oil grooves. 1. Strip paint from the subject links with a paint remover or lacquer thinner, Specification No. AN-TT-T-256 or equivalent. Do not use scraper or wire brush on links, because small cracks may be filled in and covered. 2. Visually inspect main rotor links, P/N VS 36181 by one of the following methods for cracks around link pin hole and longitudinally along what was the flash line in original forging. (See Figure 1.) If cracks are present, links should be scrapped. AD 47-35-01 (a) Visual inspection after re-anodizing; or (b) By caustic etching; or (c) By an approved fluorescent-black light method. 3. Machine oil grooves. (See Figure 1.) 4. Remove burrs and clean after machining. 5. Inspect the two bearings removed from each of the three subject links. (a) If bearings removed are P/N AT-16, replace with P/N AT-16-OH bearings on assembly. (Bearing AT-16-OH is an AT-16 bearing with an oil hole added to its outer race.) (b) If bearings removed are P/N AT-16-OH and retainer washers are damaged or show evidence of foreign matter, they are to be replaced. (Sikorsky Service Bulletin R-4B No. 10 and Army T. O. 01-230HA-15 also cover this same subject.) FOOTER:
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