AD 74-25-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-61L | Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C |
| aircraft | Sikorsky Aircraft Corporation | S-61N | Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C |
| aircraft | Sikorsky Aircraft Corporation | S-61NM | Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C |
| aircraft | Sikorsky Aircraft Corporation | S-61R | Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C |
Unsafe Condition
The main rotor blades may have pockets that could fail due to fatigue cracking, leading to blade separation and loss of control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Reduce maximum never exceed speed to 110 knots and install placards near airspeed indicators stating 'Never exceed speed 110 knots'.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within 5 hours time in service after the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Models S-61L, S-61N, S-61NM, S-61R helicopters including Military CH-3C with main rotor blades series S6115-20501, S6115-20601, S6117-20101, S6188-15001 except blades with serial numbers subsequent to 61M-6350-6105 or replaced by Sikorsky after October 30, 1972.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Main Rotor Blades
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_74-25-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Milit...Show more Subject: Main Rotor Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/06/1974 Make: Sikorsky Aircraft Corporation Model: S-61L | S-61N | S-61NM | S-61R Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 74-25-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2030 AD NUMBER: 74-25-05 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C ACTION: SUMMARY: DATES: Effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated November 6, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-05 SIKORSKY: Amendment 39-2030. Applies to S-61L, S-61N, S-61NM and S- 61R helicopters certificated in all categories including Military Type CH-3C helicopters equipped with S6115-20501 series, S6115-20601 series, S6117-20101 series, and S6188-15001 series main rotor blades except for blades with serial numbers subsequent to 61M-6350-6105 and blades which have had all main rotor blade pockets replaced by Sikorsky Aircraft after October 30, 1972. Compliance required within 5 hours time in service after the effective date of this AD. The maximum never exceed speed is hereby reduced to 110 knots. Install placards as close as practicable to the airspeed indicators reading as follows: "Never exceed speed 110 knots." This supersedes telegram dated October 8, 1974 and supersedes the maximum never exceed speed established by Airworthiness Directive 74-20-7, Amendment 39-1989. This amendment becomes effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated November 6, 1974. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_74-25-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 74-25-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Milit...Show more Subject: Main Rotor Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 11/06/1974 Make: Sikorsky Aircraft Corporation Model: S-61L | S-61N | S-61NM | S-61R 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: 74-25-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2030 AD NUMBER: 74-25-05 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-61L, S-61N, S-61NM and S-61R Helicopters Including Military CH-3C ACTION: SUMMARY: DATES: Effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated November 6, 1974. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 74-25-05 SIKORSKY: Amendment 39-2030. Applies to S-61L, S-61N, S-61NM and S- 61R helicopters certificated in all categories including Military Type CH-3C helicopters equipped with S6115-20501 series, S6115-20601 series, S6117-20101 series, and S6188-15001 series main rotor blades except for blades with serial numbers subsequent to 61M-6350-6105 and blades which have had all main rotor blade pockets replaced by Sikorsky Aircraft after October 30, 1972. Compliance required within 5 hours time in service after the effective date of this AD. The maximum never exceed speed is hereby reduced to 110 knots. Install placards as close as practicable to the airspeed indicators reading as follows: "Never exceed speed 110 knots." This supersedes telegram dated October 8, 1974 and supersedes the maximum never exceed speed established by Airworthiness Directive 74-20-7, Amendment 39-1989. This amendment becomes effective upon publication in the FEDERAL REGISTER for all persons except those to whom it was made effective immediately by telegram dated November 6, 1974. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
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