AD 50-08-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-51 | Airworthiness Directives; Sikorsky Model S-51 Helicopters |
Unsafe Condition
Cracks in the upper longerons of the S-10-20-3003 tail cone mounting assembly adjacent to the generator support plate, clamps, and welds.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the upper longerons (Drawing S-520879) for cracks near the generator support plate, clamps, and welds. Reinforce or replace cracked members before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
at each 25-hour inspection
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Model S-51 Helicopters, all serial numbers
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Tail Cone Mounting Longerons
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_50-08-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-08-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model S-51 Helicopters Subject: Tail Cone Mounting Longerons Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sikorsky Aircraft Corporation Model: S-51 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 50-08-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-08-01 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model S-51 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-08-01 SIKORSKY: Applies to All Model S-51 Helicopters. Compliance required at each 25-hour inspection. Inspect the upper longerons, Drawing S-520879, of the S-10-20-3003 tail cone mounting assembly for cracks in the area adjacent to the generator support plate and clamps, and in all the welds on the longerons adjacent to the clamps. If cracks are found, the defective member should be reinforced or replaced prior to continuing flight. (Sikorsky Service Information Circular No. 38, Revision A, dated January 4, 1950, covers this same subject.) This supersedes AD 48-11-03. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_50-08-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-08-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Model S-51 Helicopters Subject: Tail Cone Mounting Longerons Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Sikorsky Aircraft Corporation Model: S-51 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: 50-08-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-08-01 SUBJECT HEADING: Airworthiness Directives; Sikorsky Model S-51 Helicopters ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-08-01 SIKORSKY: Applies to All Model S-51 Helicopters. Compliance required at each 25-hour inspection. Inspect the upper longerons, Drawing S-520879, of the S-10-20-3003 tail cone mounting assembly for cracks in the area adjacent to the generator support plate and clamps, and in all the welds on the longerons adjacent to the clamps. If cracks are found, the defective member should be reinforced or replaced prior to continuing flight. (Sikorsky Service Information Circular No. 38, Revision A, dated January 4, 1950, covers this same subject.) This supersedes AD 48-11-03. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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