AD 89-07-12

final rule

Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76 Series Helicopters

AD Number
89-07-12
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-76 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-76B Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76 Series Helicopters

Unsafe Condition

Fatigue failure of the tail rotor component could result in a reduction of directional control and hazardous tail rotor vibration in the helicopter.

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

Required Actions

Replace the tail rotor horn, P/N 76101-05006, with a serviceable one before it accumulates 12,000 hours' time in service. Initial replacement must occur within 100 hours' time in service after the AD's effective date or before 12,000 hours' time in service, whichever is later. Use tail rotor blade bonded assembly hours if component records are unavailable.

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

Compliance Time

Within the next 100 hours' time in service after the effective date of this AD or before the accumulation of 12,000 hours' time in service, whichever occurs later

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

Affected Aircraft

Sikorsky Aircraft Corporation Model S-76A and S-76B helicopters equipped with tail rotor horn P/N 76101-05006.

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

Federal Register Abstract

Tail Rotor Horn

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_89-07-12.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
89-07-12
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76 Series Helicopters
Subject:
Tail Rotor Horn
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/27/1989
Make:
Sikorsky Aircraft Corporation
Model:
S-76A | S-76B
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Superseded AD: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:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 89-07-12
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-6171

AD NUMBER:   89-07-12

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

ACTION:  

SUMMARY:  

DATES:   Effective April 27, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-07-12 SIKORSKY AIRCRAFT: Amendment 39-6171.

Applicability: Model S-76 series helicopters, certificated in any category, that are equipped with tail rotor horn, P/N 76101-05006.

Compliance: Required as indicated, unless already accomplished.

To prevent possible fatigue failure of the tail rotor component, which could result in a reduction of directional control and hazardous tail rotor vibration in the helicopter, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD or before the accumulation of 12,000 hours time in service, whichever occurs later, replace the tail rotor horn, P/N 76101-05006, with a serviceable tail rotor horn that has not exceeded 12,000 hours' time in service. Thereafter, replace the tail rotor horn P/N 76101-05006, with a serviceable tail rotor horn before the accumulation of 12,000 hours' time in service.

(b) Operators who have not kept records of hours' time in service on individual tail rotor horn component parts must substitute the hours' time in service of the tail rotor blade bonded assembly, P/N 76101-05020 or P/N 76088-20077.

(c) For purposes of complying with this AD, the hours' time in service for the individual tail rotor horn and blade components that were not installed at the time of issuance of the initial rotorcraft airworthiness certificate must be determined from rotorcraft records.

(d) Upon request, an alternate means of compliance which provides a level of safety equivalent to the requirements of this AD may be used when approved by the Manager, Boston Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803, telephone (617) 273-7118.

(e) Upon submission of substantiating data by an owner or operator through an FAA Aviation Safety Inspector, the Manager, Boston Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803, telephone (617) 273-7118, may adjust the compliance time specified in this AD.

This amendment (39-6171, AD 89-07-12) becomes effective on April 27, 1989.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_89-07-12.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
89-07-12
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76 Series Helicopters
Subject:
Tail Rotor Horn
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/27/1989
Make:
Sikorsky Aircraft Corporation
Model:
S-76A | S-76B
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:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 89-07-12
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-6171

AD NUMBER:   89-07-12

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

ACTION:  

SUMMARY:  

DATES:   Effective April 27, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-07-12 SIKORSKY AIRCRAFT: Amendment 39-6171.

Applicability: Model S-76 series helicopters, certificated in any category, that are equipped with tail rotor horn, P/N 76101-05006.

Compliance: Required as indicated, unless already accomplished.

To prevent possible fatigue failure of the tail rotor component, which could result in a reduction of directional control and hazardous tail rotor vibration in the helicopter, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD or before the accumulation of 12,000 hours time in service, whichever occurs later, replace the tail rotor horn, P/N 76101-05006, with a serviceable tail rotor horn that has not exceeded 12,000 hours' time in service. Thereafter, replace the tail rotor horn P/N 76101-05006, with a serviceable tail rotor horn before the accumulation of 12,000 hours' time in service.

(b) Operators who have not kept records of hours' time in service on individual tail rotor horn component parts must substitute the hours' time in service of the tail rotor blade bonded assembly, P/N 76101-05020 or P/N 76088-20077.

(c) For purposes of complying with this AD, the hours' time in service for the individual tail rotor horn and blade components that were not installed at the time of issuance of the initial rotorcraft airworthiness certificate must be determined from rotorcraft records.

(d) Upon request, an alternate means of compliance which provides a level of safety equivalent to the requirements of this AD may be used when approved by the Manager, Boston Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803, telephone (617) 273-7118.

(e) Upon submission of substantiating data by an owner or operator through an FAA Aviation Safety Inspector, the Manager, Boston Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803, telephone (617) 273-7118, may adjust the compliance time specified in this AD.

This amendment (39-6171, AD 89-07-12) becomes effective on April 27, 1989.

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.