AD 89-07-09

final rule

Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters

AD Number
89-07-09
Status
final_rule
Effective Date
Product Category
aircraft
Docket
89-ASW-4
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-61A Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61D Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61E Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61L Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61N Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61NM Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61R Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
aircraft Sikorsky Aircraft Corporation S-61V Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters

Unsafe Condition

Failure of the main rotor gearbox helical gear Part Number S6135-20620-003 with specified serial numbers could occur.

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

Required Actions

Inspect the main rotor gearbox to identify the helical gear serial number. Replace the gear if its serial number is listed in this AD with an airworthy one having a different serial number. Ferrying is allowed under FAR Sections 21.197 and 21.199.

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

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

Affected Aircraft

Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, S-61L, S-61N, S-61NM, S-61R, S-61V helicopters equipped with main rotor gearbox helical gear Part Number S6135-20620-003, serial numbers 1086, 1087, 1089, 1090-1099, 1101, 1103-1113, 1116, 1117, 1130, 1132.

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

Federal Register Abstract

Main Rotor Gearbox

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_89-07-09.html
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AD Number:
89-07-09
Document Type:
AD Final Rules
Docket Number:
89-ASW-4
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
Subject:
Main Rotor Gearbox
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/20/1989
Make:
Sikorsky Aircraft Corporation
Model:
S-61A | S-61D | S-61E | S-61L | S-61N | S-61NM | S-61R | S-61V
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: 89-07-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-ASW-4

AMENDMENT:   39-6172

AD NUMBER:   89-07-09

SUBJECT HEADING:   Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters


ACTION:  

SUMMARY:  

DATES:   Effective April 20, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-07-09 SIKORSKY AIRCRAFT: Amendment 39-6172.

Applicability: All Model S-61 series helicopters, certificated in any category, equipped with main rotor gearbox helical gear Part Number S6135-20620-003, Serial Numbers 1086, 1087, 1089, and 1090 through and including 1099, 1101, 1103, through and including 1113, 1116, 1117, 1130, 1132. (Docket No. 89-ASW-4).

Compliance: Required within the next 100 hours' time in service, unless already accomplished.

To prevent possible failure of the helical gear, accomplish the following:

(a) Inspect the main rotor gearbox to identify the serial number of the helical gear installed. If the helical gear is identified with a serial number listed in this AD, replace it with an airworthy helical gear which has a serial number other than listed in this AD.

NOTE: Sikorsky Aircraft message CBT-TS-89-002 dated January 23, 1989, applies to this AD.

(b) Aircraft may be ferried in accordance with the provisions of FAR Sections 21.197 and 21.199 to a base where the provisions of the AD can be accomplished.

(c) An alternate means of compliance or an adjustment of the initial compliance time which provides an equivalent level of safety may be used if approved by the Manager, Boston Aircraft Certification Office, Federal Aviation Administration, 12 New England Executive Park, Burlington, MA 01803.

The noted service information may be obtained from Sikorsky Aircraft, 6900 Main Street, Mail Stop S409A, Stratford, CT 06601-1381.

This amendment (39-6172, AD 89-07-09) becomes effective on April 20, 1989.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_89-07-09.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
89-07-09
Document Type:
AD Final Rules
Docket Number:
89-ASW-4
Subject Heading:
Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters
Subject:
Main Rotor Gearbox
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
04/20/1989
Make:
Sikorsky Aircraft Corporation
Model:
S-61A | S-61D | S-61E | S-61L | S-61N | S-61NM | S-61R | S-61V
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: 89-07-09
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-ASW-4

AMENDMENT:   39-6172

AD NUMBER:   89-07-09

SUBJECT HEADING:   Airworthiness Directives; SIKORSKY AIRCRAFT Model S-61 Series Helicopters


ACTION:  

SUMMARY:  

DATES:   Effective April 20, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-07-09 SIKORSKY AIRCRAFT: Amendment 39-6172.

Applicability: All Model S-61 series helicopters, certificated in any category, equipped with main rotor gearbox helical gear Part Number S6135-20620-003, Serial Numbers 1086, 1087, 1089, and 1090 through and including 1099, 1101, 1103, through and including 1113, 1116, 1117, 1130, 1132. (Docket No. 89-ASW-4).

Compliance: Required within the next 100 hours' time in service, unless already accomplished.

To prevent possible failure of the helical gear, accomplish the following:

(a) Inspect the main rotor gearbox to identify the serial number of the helical gear installed. If the helical gear is identified with a serial number listed in this AD, replace it with an airworthy helical gear which has a serial number other than listed in this AD.

NOTE: Sikorsky Aircraft message CBT-TS-89-002 dated January 23, 1989, applies to this AD.

(b) Aircraft may be ferried in accordance with the provisions of FAR Sections 21.197 and 21.199 to a base where the provisions of the AD can be accomplished.

(c) An alternate means of compliance or an adjustment of the initial compliance time which provides an equivalent level of safety may be used if approved by the Manager, Boston Aircraft Certification Office, Federal Aviation Administration, 12 New England Executive Park, Burlington, MA 01803.

The noted service information may be obtained from Sikorsky Aircraft, 6900 Main Street, Mail Stop S409A, Stratford, CT 06601-1381.

This amendment (39-6172, AD 89-07-09) becomes effective on April 20, 1989.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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