AD 75-11-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Erickson Air-Crane | S-64E | Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters |
| aircraft | Erickson Air-Crane | S-64F | Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters |
Unsafe Condition
Failure of the torquemeter engine to gearbox shaft and gear assembly and consequent secondary damage to the main rotor control system components.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove torquemeter engine to gearbox shaft and gear assemblies with 3000 or more hours total time in service. Replace with P/N 6435-20564-042 assemblies having less than 3000 hours time in service, P/N 6435-20564-044 assemblies, or an equivalent approved by the FAA. Ensure replacement P/N 6435-20564-042 assemblies are removed before accumulating 3000 hours time in service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
prior to further flight
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Affected Aircraft
Sikorsky Models S-64E and S-64F helicopters with torquemeter engine to gearbox shaft and gear assemblies P/N 6435-20564-042
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Gear Box Shaft and Gear Assy
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_75-11-11.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-11-11 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters Subject: Gear Box Shaft and Gear Assy Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/02/1975 Make: Erickson Air-Crane Model: S-64E | S-64F Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 75-11-11 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2432 AD NUMBER: 75-11-11 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters ACTION: SUMMARY: DATES: Effective December 2, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-11-11 SIKORSKY AIRCRAFT: Amendment 39-2217 as amended by Amendment 39-2432. Applies to all Sikorsky Aircraft Model S-64E and Model S-64F helicopters. To prevent failure of the torquemeter engine to gearbox shaft and gear assembly and consequent secondary damage to the main rotor control system components, remove prior to further flight, torquemeter engine to gearbox shaft and gear assemblies, P/N 6435-20564-042, with 3000 or more hours total time in service. Replace those assemblies removed with P/N 6435-20564-042 assemblies which have less than 3000 hours total time in service, or with P/N 6435-20564-044 assemblies, or with an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region. All replacement P/N 6435-20564-042 assemblies must be removed prior to the accumulation of 3000 hours time in service. Amendment 39-2217 became effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram. This amendment 39-2432 becomes effective December 2, 1975. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_75-11-11.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 75-11-11 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters Subject: Gear Box Shaft and Gear Assy Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 12/02/1975 Make: Erickson Air-Crane Model: S-64E | S-64F 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: 75-11-11 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2432 AD NUMBER: 75-11-11 SUBJECT HEADING: Airworthiness Directives; Sikorsky Models S-64E and S-64F Helicopters ACTION: SUMMARY: DATES: Effective December 2, 1975. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 75-11-11 SIKORSKY AIRCRAFT: Amendment 39-2217 as amended by Amendment 39-2432. Applies to all Sikorsky Aircraft Model S-64E and Model S-64F helicopters. To prevent failure of the torquemeter engine to gearbox shaft and gear assembly and consequent secondary damage to the main rotor control system components, remove prior to further flight, torquemeter engine to gearbox shaft and gear assemblies, P/N 6435-20564-042, with 3000 or more hours total time in service. Replace those assemblies removed with P/N 6435-20564-042 assemblies which have less than 3000 hours total time in service, or with P/N 6435-20564-044 assemblies, or with an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region. All replacement P/N 6435-20564-042 assemblies must be removed prior to the accumulation of 3000 hours time in service. Amendment 39-2217 became effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram. This amendment 39-2432 becomes effective December 2, 1975. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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