AD 81-09-07

final rule

Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters

AD Number
81-09-07
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of a helicopter rotor hub assembly
Problem area Rotor system

Applicability

TypeManufacturerModelDetails
aircraft Sikorsky Aircraft Corporation S-76A Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters

Unsafe Condition

Cracked bolts in the main rotor blade tip plate attachment joint

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace NAS624H6 bolts with equivalent approved procedure, inspect for torque, and report discrepancies within 24 hours to the specified FAA office.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within the next 25 hours time in service after May 7, 1981, for blades with 340+ hours, or before accumulating 365 hours time in service for blades with less than 340 hours as of May 7, 1981.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Sikorsky Aircraft Model S-76A series helicopters with P/N 76150-09000 series and P/N 76150-09100-041, -042, -043 main rotor blades.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Main Rotor Blades

Applicability Source Text

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AD Number:
81-09-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters
Subject:
Main Rotor Blades
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/07/1981
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Superseded AD: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Superseded By: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: 81-09-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4099

AD NUMBER:   81-09-07

SUBJECT HEADING:   Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective May 7, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-09-07 SIKORSKY AIRCRAFT: Amendment 39-4099. Applies to S-76A series helicopters certificated in all categories with P/N 76150-09000 series and P/N 76150-09100-041, -042, -043, main rotor blades. For main rotor blades with 340 or more hours time in service, compliance required within the next 25 hours time in service after the effective date of this AD, unless already accomplished.

For main rotor blades with less than 340 hours time in service on the effective date of this AD, compliance required before the accumulation of 365 hours time in service.

To prevent operation with cracked bolts in the main rotor blade tip plate attachment joint, accomplish the following:

1. In accordance with Sikorsky Alert Service Bulletin No. 76-65-23, dated April 16, 1981, replace the four NAS624H6 bolts which mate the 76150-09030 tip plate assembly with the 76150-09000 or 76150-09100 main rotor blade, per paragraphs D(1) through D(8), and subsequently inspect for torque per paragraph D(9), or an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region.

2. Report within 24 hours any discrepancies found during the rework and inspections required herein, including main rotor blade time in service, to the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803.

Reporting approved by the Office of Management and Budget under OMB No. 04-401 74.

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) (l). 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 01803, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C.

This AD supersedes AD 80-14-05.

This amendment becomes effective May 7, 1981.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_81-09-07.html
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Print/Save as PDF
Document Versions
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Details
AD Number:
81-09-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters
Subject:
Main Rotor Blades
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
05/07/1981
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: 81-09-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4099

AD NUMBER:   81-09-07

SUBJECT HEADING:   Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A Series Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective May 7, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-09-07 SIKORSKY AIRCRAFT: Amendment 39-4099. Applies to S-76A series helicopters certificated in all categories with P/N 76150-09000 series and P/N 76150-09100-041, -042, -043, main rotor blades. For main rotor blades with 340 or more hours time in service, compliance required within the next 25 hours time in service after the effective date of this AD, unless already accomplished.

For main rotor blades with less than 340 hours time in service on the effective date of this AD, compliance required before the accumulation of 365 hours time in service.

To prevent operation with cracked bolts in the main rotor blade tip plate attachment joint, accomplish the following:

1. In accordance with Sikorsky Alert Service Bulletin No. 76-65-23, dated April 16, 1981, replace the four NAS624H6 bolts which mate the 76150-09030 tip plate assembly with the 76150-09000 or 76150-09100 main rotor blade, per paragraphs D(1) through D(8), and subsequently inspect for torque per paragraph D(9), or an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region.

2. Report within 24 hours any discrepancies found during the rework and inspections required herein, including main rotor blade time in service, to the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803.

Reporting approved by the Office of Management and Budget under OMB No. 04-401 74.

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) (l). 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 01803, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C.

This AD supersedes AD 80-14-05.

This amendment becomes effective May 7, 1981.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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