AD 78-20-05 R4
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-61A | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61D | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61E | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61L | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61N | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61NM | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61R | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-61V | Airworthiness Directives; Sikorsky Models S-61 Series Helicopters |
Unsafe Condition
Failure of main rotor spindles due to cracks in P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies).
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Required Actions
Conduct ultrasonic inspections within the next 20 hours' time in service (or within last 50 hours if already done), and thereafter every 70 hours' time in service. Replace cracked spindles before further flight. Report any cracks with details to the FAA.
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Compliance Time
Within the next 20 hours' time in service, unless already accomplished within the last 50 hours' time in service, after the effective date of this amendment, and thereafter at intervals not to exceed 70 hours time in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Models S-61A, S-61D, S-61E, S-61L, S-61N, S-61NM, S-61R, S-61V helicopters equipped with main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies).
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Federal Register Abstract
Main Rotor Spindles
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_78-20-05_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-20-05 R4 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-61 Series Helicopters Subject: Main Rotor Spindles Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/25/1983 Make: Sikorsky Aircraft Corporation Model: S-61A | S-61D | S-61E | S-61L | S-61N | S-61NM | S-61R | S-61V 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: 78-20-05 R4 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4648 AD NUMBER: 78-20-05 R4 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-61 Series Helicopters ACTION: SUMMARY: DATES: Effective May 25, 1983. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-20-05 R4 SIKORSKY AIRCRAFT: Amendment 39-3305 as amended by Amendment 39-3425 and Amendment 39-3444 and 39-3838 is further amended by Amendment 39-4648. Applies to S-61 series helicopters certificated in all categories, including military counterparts, equipped with main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies). Compliance required as indicated. To preclude the possibility of failure of main rotor spindles, accomplish the following. 1. Within the next 20 hours' time in service, unless already accomplished within the last 50 hours' time in service, after the effective date of this amendment, and thereafter at intervals not to exceed 70 hours time in service, conduct ultrasonic inspections of all main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies), (plated and unplated), with 70 or more hours time in service, in accordance with the inspection method of Sikorsky Service Bulletin No. 61B10-33F, or an equivalent method approved by the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. 2. If a crack is found during the above inspections, replace the cracked spindle with a new spindle or a serviceable spindle prior to further flight. 3. Report in writing any cracks found during the above inspections to the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. Each report must include the length and location of the cracks and total time in service of the spindle (reporting approved by the Office of Management and Budget under OMB No. 04-R0174). 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 United Technologies Corporation, Sikorsky Aircraft, North Main Street, Stratford, Connecticut 06601, Attn: S-61 Commercial Product Support Department. These documents also may be examined in the Office of the Regional Counsel, Federal Aviation Administration, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76106. Amendment 39-3305 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated July 31, 1978. Amendment 39-3425 became effective upon publication in the FEDERAL REGISTER. Amendment 39-3444 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated March 9, 1979. Amendment 39-3838 became effective June 30, 1980. This Amendment 39-4648 becomes effective May 25, 1983. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_78-20-05_R.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-20-05 R4 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-61 Series Helicopters Subject: Main Rotor Spindles Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/25/1983 Make: Sikorsky Aircraft Corporation Model: S-61A | S-61D | S-61E | S-61L | S-61N | S-61NM | S-61R | S-61V 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: 78-20-05 R4 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-4648 AD NUMBER: 78-20-05 R4 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-61 Series Helicopters ACTION: SUMMARY: DATES: Effective May 25, 1983. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-20-05 R4 SIKORSKY AIRCRAFT: Amendment 39-3305 as amended by Amendment 39-3425 and Amendment 39-3444 and 39-3838 is further amended by Amendment 39-4648. Applies to S-61 series helicopters certificated in all categories, including military counterparts, equipped with main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies). Compliance required as indicated. To preclude the possibility of failure of main rotor spindles, accomplish the following. 1. Within the next 20 hours' time in service, unless already accomplished within the last 50 hours' time in service, after the effective date of this amendment, and thereafter at intervals not to exceed 70 hours time in service, conduct ultrasonic inspections of all main rotor P/N S6112-23025-1 spindles (S6112-23027-006 spindle assemblies) and S6110-23325 series spindles (S6110-23327 series spindle assemblies), (plated and unplated), with 70 or more hours time in service, in accordance with the inspection method of Sikorsky Service Bulletin No. 61B10-33F, or an equivalent method approved by the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. 2. If a crack is found during the above inspections, replace the cracked spindle with a new spindle or a serviceable spindle prior to further flight. 3. Report in writing any cracks found during the above inspections to the Manager, Boston Aircraft Certification Branch, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. Each report must include the length and location of the cracks and total time in service of the spindle (reporting approved by the Office of Management and Budget under OMB No. 04-R0174). 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 United Technologies Corporation, Sikorsky Aircraft, North Main Street, Stratford, Connecticut 06601, Attn: S-61 Commercial Product Support Department. These documents also may be examined in the Office of the Regional Counsel, Federal Aviation Administration, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76106. Amendment 39-3305 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated July 31, 1978. Amendment 39-3425 became effective upon publication in the FEDERAL REGISTER. Amendment 39-3444 became effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated March 9, 1979. Amendment 39-3838 became effective June 30, 1980. This Amendment 39-4648 becomes effective May 25, 1983. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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