AD 90-01-11

final rule

Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters

AD Number
90-01-11
Status
final_rule
Effective Date
Product Category
aircraft
Docket
89-ASW-50
FR Citation
This information is not available.
Technical illustration of a helicopter rotor hub assembly
Problem area Rotor system

Applicability

TypeManufacturerModelDetails
aircraft Bell Helicopter Textron, Inc. 204B Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters

Unsafe Condition

Failure of the tail rotor duplex bearing set, P/N 204-040-424-001, could result in loss of tail rotor control and subsequent loss of the helicopter.

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

Required Actions

Remove the tail rotor gearbox duplex bearing set, P/N 204-040-424-001, within 100 hours' time in service after the effective date and replace with a serviceable part before further flight. The helicopter may be flown to a base where AD requirements can be accomplished with FAA approval.

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

Compliance Time

within 100 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

Bell Helicopter Textron, Inc. Model 204B helicopters with tail rotor gearbox duplex bearing sets P/N 204-040-424-001, serial numbers 1 thru 182, MB183 thru MB382, MB442, MB486, MB513, MB518, MB519, MB524, MB530, MB531, MB544, MB545, MB548, MB549, MB551, MB553, MB554, MB561, MB659, MB743, MB744, MB760 thru MB769, and MB927 thru MB936.

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

Federal Register Abstract

Tail Rotor Gearbox Bearing Set

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_90-01-11.html
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AD Number:
90-01-11
Document Type:
AD Final Rules
Docket Number:
89-ASW-50
Subject Heading:
Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters
Subject:
Tail Rotor Gearbox Bearing Set
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/01/1990
Make:
Bell Helicopter Textron, Inc.
Model:
204B
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Superseded AD: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Superseded By: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: 90-01-11
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-ASW-50

AMENDMENT:   39-6450

AD NUMBER:   90-01-11

SUBJECT HEADING:   Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective February 1, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-01-11 BELL HELICOPTER TEXTRON, INC.: Amendment 39-6450. Docket No. 89-ASW-50.

Applicability: Bell Helicopter Textron, Inc., Model 204B helicopters, certificated in any category, with tail rotor gearbox duplex bearing sets, P/N 204-040-424-001, with serial numbers (S/N's) 1 thru 182, MB183 thru MB382, MB442, MB486, MB513, MB518, MB519, MB524, MB530, MB531, MB544, MB545, MB548, MB549, MB551, MB553, MB554, MB561, MB659, MB743, MB744, MB760 thru MB769 and MB927 thru MB936, installed in tail rotor gearbox output quill, P/N 204-040-012-009.

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the tail rotor duplex bearing which could result in loss of tail rotor control and subsequent loss of the helicopter, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD, remove the tail rotor gearbox duplex bearing set, P/N 204-040-424-001, from service and replace with a serviceable part before further flight.

(b) In accordance with FAR Sections 21.197 and 21.199, the helicopter may be flown to a base where the requirements of this AD may be accomplished.

(c) An alternate method of compliance or adjustment of the compliance time which provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Certification Office, ASW-170, Rotorcraft Directorate, FAA, Southwest Region, Fort Worth, Texas.

This amendment (39-6450, AD 90-01-11) becomes effective on February 1, 1990.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_90-01-11.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
90-01-11
Document Type:
AD Final Rules
Docket Number:
89-ASW-50
Subject Heading:
Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters
Subject:
Tail Rotor Gearbox Bearing Set
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
02/01/1990
Make:
Bell Helicopter Textron, Inc.
Model:
204B
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: 90-01-11
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-ASW-50

AMENDMENT:   39-6450

AD NUMBER:   90-01-11

SUBJECT HEADING:   Airworthiness Directives; BELL HELICOPTER TEXTRON, INC. Model 204B Helicopters

ACTION:  

SUMMARY:  

DATES:   Effective February 1, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-01-11 BELL HELICOPTER TEXTRON, INC.: Amendment 39-6450. Docket No. 89-ASW-50.

Applicability: Bell Helicopter Textron, Inc., Model 204B helicopters, certificated in any category, with tail rotor gearbox duplex bearing sets, P/N 204-040-424-001, with serial numbers (S/N's) 1 thru 182, MB183 thru MB382, MB442, MB486, MB513, MB518, MB519, MB524, MB530, MB531, MB544, MB545, MB548, MB549, MB551, MB553, MB554, MB561, MB659, MB743, MB744, MB760 thru MB769 and MB927 thru MB936, installed in tail rotor gearbox output quill, P/N 204-040-012-009.

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the tail rotor duplex bearing which could result in loss of tail rotor control and subsequent loss of the helicopter, accomplish the following:

(a) Within the next 100 hours' time in service after the effective date of this AD, remove the tail rotor gearbox duplex bearing set, P/N 204-040-424-001, from service and replace with a serviceable part before further flight.

(b) In accordance with FAR Sections 21.197 and 21.199, the helicopter may be flown to a base where the requirements of this AD may be accomplished.

(c) An alternate method of compliance or adjustment of the compliance time which provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Certification Office, ASW-170, Rotorcraft Directorate, FAA, Southwest Region, Fort Worth, Texas.

This amendment (39-6450, AD 90-01-11) becomes effective on February 1, 1990.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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