AD 89-23-02

final rule

Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes

AD Number
89-23-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
89-NM-100-AD
FR Citation
This information is not available.
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 757-200 Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 757-200CB Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 757-200PF Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 757-300 Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 767-200 Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 767-300 Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
aircraft The Boeing Company 767-300F Series Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes

Unsafe Condition

Possible complete loss of hydraulic power due to potential failure of the Ram Air Turbine (RAT) hydraulic pump when the RAT Ground Checkout Module (GCM) is not properly reworked or replaced.

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

Required Actions

Remove and rework or replace the RAT Ground Checkout Module (GCM) per applicable Boeing Service Bulletins. Inspect the downstream filter screen of the removed GCM before returning to service. If the screen is damaged, missing, or previously not inspected, test or replace the RAT hydraulic pump prior to further flight. Replace the pump if it is damaged during testing.

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

Compliance Time

within the next 6,000 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

Boeing Model 757 and 767 series airplanes listed in Boeing Alert Service Bulletins 757-29A0037, Revision 1, and 767-29A0035, Revision 1, both dated November 23, 1988.

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

Federal Register Abstract

Ram Air Turbine

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_89-23-02.html
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AD Number:
89-23-02
Document Type:
AD Final Rules
Docket Number:
89-NM-100-AD
Subject Heading:
Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
Subject:
Ram Air Turbine
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/01/1989
Make:
The Boeing Company
Model:
757-200 Series | 757-200CB Series | 757-200PF Series | 757-300 Series | 767-200 Series | 767-300 Ser...Show more
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 89-23-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-NM-100-AD

AMENDMENT:   39-6373

AD NUMBER:   89-23-02

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 1, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-23-02 BOEING: Amendment 39-6373. Docket No. 89-NM-100-AD.

Applicability: Model 757 and 767 series airplanes, as listed in Boeing Alert Service Bulletins 757-29A0037, Revision 1, and 767-29A0035, Revision 1, both dated November 23, 1988, certificated in any category.

Compliance: Required within the next 6,000 hours time-in-service after the effective date of this AD, unless previously accomplished.

To prevent the possible complete loss of hydraulic power, accomplish the following:

A. Remove and rework or replace the Ram Air Turbine (RAT) Ground Checkout Module (GCM) in accordance with Boeing Service Bulletin 757-29A0037, Revision 1, dated November 23, 1988, or Revision 2, dated August 3, 1989 (for Model 757 airplanes); or Boeing Service Bulletin 767-29A0035, Revision 1, dated November 23, 1989, or Revision 2, dated August 3, 1989 (for Model 767 airplanes); as appropriate. Prior to returning the airplane to service:

1. If the RAT has been operated or tested since the airplane delivery, prior to returning the airplane to service, inspect the downstream filter screen of the removed GCM.

2. If the screen is damaged or missing, or if GCM has been removed previously without inspecting the screen, prior to further flight, either test the RAT hydraulic pump or replace it in accordance with the applicable service bulletins.

3. If the RAT hydraulic pump is tested and found to be damaged, prior to further flight, replace it with a serviceable pump in accordance with the applicable service bulletin.

B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6373, AD 89-23-02) becomes effective on December 1, 1989.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_89-23-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
89-23-02
Document Type:
AD Final Rules
Docket Number:
89-NM-100-AD
Subject Heading:
Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes
Subject:
Ram Air Turbine
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/01/1989
Make:
The Boeing Company
Model:
757-200 Series | 757-200CB Series | 757-200PF Series | 757-300 Series | 767-200 Series | 767-300 Ser...Show more
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 89-23-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   89-NM-100-AD

AMENDMENT:   39-6373

AD NUMBER:   89-23-02

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 757 and 767 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 1, 1989.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
89-23-02 BOEING: Amendment 39-6373. Docket No. 89-NM-100-AD.

Applicability: Model 757 and 767 series airplanes, as listed in Boeing Alert Service Bulletins 757-29A0037, Revision 1, and 767-29A0035, Revision 1, both dated November 23, 1988, certificated in any category.

Compliance: Required within the next 6,000 hours time-in-service after the effective date of this AD, unless previously accomplished.

To prevent the possible complete loss of hydraulic power, accomplish the following:

A. Remove and rework or replace the Ram Air Turbine (RAT) Ground Checkout Module (GCM) in accordance with Boeing Service Bulletin 757-29A0037, Revision 1, dated November 23, 1988, or Revision 2, dated August 3, 1989 (for Model 757 airplanes); or Boeing Service Bulletin 767-29A0035, Revision 1, dated November 23, 1989, or Revision 2, dated August 3, 1989 (for Model 767 airplanes); as appropriate. Prior to returning the airplane to service:

1. If the RAT has been operated or tested since the airplane delivery, prior to returning the airplane to service, inspect the downstream filter screen of the removed GCM.

2. If the screen is damaged or missing, or if GCM has been removed previously without inspecting the screen, prior to further flight, either test the RAT hydraulic pump or replace it in accordance with the applicable service bulletins.

3. If the RAT hydraulic pump is tested and found to be damaged, prior to further flight, replace it with a serviceable pump in accordance with the applicable service bulletin.

B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6373, AD 89-23-02) becomes effective on December 1, 1989.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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