AD 81-21-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-76A | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters |
Unsafe Condition
Fatigue failures of the main rotor scissors assembly due to the use of P/Ns 76104-08020-044, -045, -046, and 76070-10005-042 main rotor rotating scissors assemblies.
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Required Actions
Replace specified main rotor rotating scissors assemblies with serviceable parts before accumulating 500 hours time in service or within 25 hours after AD effective date, whichever is later. Conduct inspections within 50 hours after AD effective date (if not done in last 50 hours) and every 100 hours thereafter for hub/scissors bearings play/wear and scissors center pivot bolt fretting/scoring/corrosion pits per specified manuals.
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Compliance Time
before further flight
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Affected Aircraft
Sikorsky Aircraft Corporation Model S-76A series helicopters certificated in all categories.
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Federal Register Abstract
Main Rotor Scissors Assembly
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_81-21-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-21-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters Subject: Main Rotor Scissors Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/08/1981 Make: Sikorsky Aircraft Corporation Model: S-76A Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 81-21-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4228 AD NUMBER: 81-21-04 SUBJECT HEADING: Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters ACTION: SUMMARY: DATES: Effective October 8, 1981. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-21-04 SIKORSKY AIRCRAFT: Amendment 39-4228. Applies to S-76A series helicopters certificated in all categories. To prevent fatigue failures of the main rotor scissors assembly: 1. Replace P/Ns 76104-08020-044, -045, and -046, and P/N 76070-10005-042 main rotor rotating scissors assemblies with a serviceable part prior to the accumulation of 500 hours time in service or within 25 hours time in service after the effective date of this AD, whichever occurs later. 2. Within the next 50 hours time in service after the effective date of this AD, unless already accomplished within the last 50 hours time in service, and thereafter at intervals not to exceed 100 hours from the last inspection, conduct inspections of the hub/scissors bearings for play and wear and the scissors center pivot bolt for fretting, scoring, and corrosion pits in accordance with Temporary Revision No. 5-24, dated September 8, 1981, or an FAA approved equivalent, Items 42A (Inspection Check 65-14-00, Page 207, dated February 16, 1980, including Temporary Revision No. 65-15, dated September 8, 1981, or an FAA approved equivalent) and 42B of the Sikorsky S-76A Maintenance Manual, 5A 4047-76-2. NOTE: "FAA approved" means approved by the Chief, Engineering and Manufacturing Branch, New England Region. The manufacturer's specifications and procedures identified and described 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 Sikorsky Aircraft, Division of United Technologies Corporation, Stratford, Connecticut 06602. These documents may also be examined at FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. This amendment becomes effective October 8, 1981. FOOTER:
Document Text
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AD Final Rules - DRS_81-21-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 81-21-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters Subject: Main Rotor Scissors Assembly Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/08/1981 Make: Sikorsky Aircraft Corporation Model: S-76A 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: 81-21-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4228 AD NUMBER: 81-21-04 SUBJECT HEADING: Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters ACTION: SUMMARY: DATES: Effective October 8, 1981. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 81-21-04 SIKORSKY AIRCRAFT: Amendment 39-4228. Applies to S-76A series helicopters certificated in all categories. To prevent fatigue failures of the main rotor scissors assembly: 1. Replace P/Ns 76104-08020-044, -045, and -046, and P/N 76070-10005-042 main rotor rotating scissors assemblies with a serviceable part prior to the accumulation of 500 hours time in service or within 25 hours time in service after the effective date of this AD, whichever occurs later. 2. Within the next 50 hours time in service after the effective date of this AD, unless already accomplished within the last 50 hours time in service, and thereafter at intervals not to exceed 100 hours from the last inspection, conduct inspections of the hub/scissors bearings for play and wear and the scissors center pivot bolt for fretting, scoring, and corrosion pits in accordance with Temporary Revision No. 5-24, dated September 8, 1981, or an FAA approved equivalent, Items 42A (Inspection Check 65-14-00, Page 207, dated February 16, 1980, including Temporary Revision No. 65-15, dated September 8, 1981, or an FAA approved equivalent) and 42B of the Sikorsky S-76A Maintenance Manual, 5A 4047-76-2. NOTE: "FAA approved" means approved by the Chief, Engineering and Manufacturing Branch, New England Region. The manufacturer's specifications and procedures identified and described 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 Sikorsky Aircraft, Division of United Technologies Corporation, Stratford, Connecticut 06602. These documents may also be examined at FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. This amendment becomes effective October 8, 1981. FOOTER:
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