AD 91-25-06

final rule

Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes

AD Number
91-25-06
Status
final_rule
Effective Date
Product Category
aircraft
Docket
91-NM-230-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 737-300 Series Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes
aircraft The Boeing Company 737-400 Series Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes
aircraft The Boeing Company 737-500 Series Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes

Unsafe Condition

Separation of the thrust reverser translating sleeve due to worn auxiliary track liners and slider fittings could cause structural damage to the airplane.

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

Required Actions

Within 14 days after the effective date, inspect each lower thrust reverser auxiliary track, liner, and slider fittings. Repeat inspections at intervals not exceeding 1,500 hours, 750 hours, or 250 hours time-in-service based on slider engagement. Replace track liners and slider fittings/auxiliary tracks if slider can be pulled out in both positions. Deactivate thrust reverser if slider can be pulled out only in deployed position. Record engagement and repeat inspections as specified.

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

Compliance Time

Within 14 days after the effective date of this AD, and repeat inspections at intervals not to exceed 1,500 hours, 750 hours, or 250 hours time-in-service as specified.

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

Affected Aircraft

BOEING Model 737-300, 737-400, and 737-500 series airplanes listed in Boeing Service Bulletin 737-78-1048, Revision 1.

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

Federal Register Abstract

Thrust Reverser Auxiliary Track

Applicability Source Text

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AD Number:
91-25-06
Document Type:
AD Final Rules
Docket Number:
91-NM-230-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes
Subject:
Thrust Reverser Auxiliary Track
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/18/1991
Make:
The Boeing Company
Model:
737-300 Series | 737-400 Series | 737-500 Series
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: 91-25-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-230-AD

AMENDMENT:   39-8106

AD NUMBER:   91-25-06

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 18, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-25-06 BOEING: Amendment 39-8106. Docket No. 91-NM-230-AD.

Applicability: Model 737-300, 737-400, and 737-500 series airplanes; as listed in Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent structural damage to the airplane as a result of separation of the thrust reverser translating sleeve due to worn auxiliary track liners and slider fittings, accomplish the following:

(a) Within 14 days after the effective date of this AD, inspect each lower thrust reverser auxiliary track, liner, and slider fittings to determine the ability of the slider to remain in the track, in accordance with the Accomplishment Instructions of Boeing Alert Service Letter Number 737-SL-78-22 (Telex M-7272-91-7201), dated November 6, 1991. Repeat this inspection thereafter at intervals not to exceed 1,500 hours, 750 hours, or 250 hours time-in-service, as determined by percent engagement of the lower auxiliary track slider, and as specified in the service letter. As a result of this inspection, accomplish the following, as applicable:

(1) If the slider can be pulled out of the track in both the deployed and stowed position, prior to further flight, replace the track liner and, if applicable, replace or repair the slider fittings and the auxiliary track, in accordance with Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990.

(2) If the slider can be pulled out of the track in only the deployed position, prior to further flight, reinsert the slider in the track and deactivate the thrust reverser in accordance with Chapter 78 of Boeing Document D6-32545, "Boeing 737 Dispatch Deviations Procedures Guide," dated June 14, 1991.

(3) If the slider cannot be pulled out of the track in either the deployed or stowed positions, record the percent engagement of the sliders in the lower auxiliary tracks, and repeat the inspection at the specified intervals in accordance with the accomplishment instructions of Boeing Alert Service Letter 737-SL-78-22 (Telex M-7272-91-7201), dated November 6, 1991.

(b) Accomplishment of the replacement of the auxiliary track liner and, if applicable, rework or replacement of the slider fittings and the auxiliary tracks, in accordance with Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990, constitutes terminating action for the inspection requirements of paragraph (a) of this AD.

(c) An alternative method 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 (ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(d) 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.

(e) The inspections, repairs, and modifications shall be done in accordance with Boeing Alert Service Letter 737-SL-78-22 (sent to operators as Telex M-7272-91-7201), dated November 6, 1991; and Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990, which contains the following list of effective pages:


Page Number	
Revision Level
	Date
1 - 4	
1
	February 22, 1990
5 - 44	
(original)
	November 22, 1989

The deactivation procedures shall be done in accordance with Chapter 78 of Boeing Document D6-32545, "Boeing 737 Dispatch Deviations Procedures Guide," dated June 14, 1991, which includes the following list of effective pages:

PAGE NUMBER	DATE
2.78-1.0,	June 14, 1991
2.78-1.2,	
2.78-2.0,	
2.78-3.0,	
2.78-4.0,	
2.78-6.0,	
2.78-7.0	
2.78-1.1	May 31, 1990
2.78-5.0	August 17, 1989

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C.

(f) This amendment (39-8106, AD 91-25-06) becomes effective on December 18, 1991.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_91-25-06.html
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Document Versions
 Feedback
Details
AD Number:
91-25-06
Document Type:
AD Final Rules
Docket Number:
91-NM-230-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes
Subject:
Thrust Reverser Auxiliary Track
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/18/1991
Make:
The Boeing Company
Model:
737-300 Series | 737-400 Series | 737-500 Series
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: 91-25-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-230-AD

AMENDMENT:   39-8106

AD NUMBER:   91-25-06

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 737-300, 737-400, and 737-500 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 18, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-25-06 BOEING: Amendment 39-8106. Docket No. 91-NM-230-AD.

Applicability: Model 737-300, 737-400, and 737-500 series airplanes; as listed in Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990; certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent structural damage to the airplane as a result of separation of the thrust reverser translating sleeve due to worn auxiliary track liners and slider fittings, accomplish the following:

(a) Within 14 days after the effective date of this AD, inspect each lower thrust reverser auxiliary track, liner, and slider fittings to determine the ability of the slider to remain in the track, in accordance with the Accomplishment Instructions of Boeing Alert Service Letter Number 737-SL-78-22 (Telex M-7272-91-7201), dated November 6, 1991. Repeat this inspection thereafter at intervals not to exceed 1,500 hours, 750 hours, or 250 hours time-in-service, as determined by percent engagement of the lower auxiliary track slider, and as specified in the service letter. As a result of this inspection, accomplish the following, as applicable:

(1) If the slider can be pulled out of the track in both the deployed and stowed position, prior to further flight, replace the track liner and, if applicable, replace or repair the slider fittings and the auxiliary track, in accordance with Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990.

(2) If the slider can be pulled out of the track in only the deployed position, prior to further flight, reinsert the slider in the track and deactivate the thrust reverser in accordance with Chapter 78 of Boeing Document D6-32545, "Boeing 737 Dispatch Deviations Procedures Guide," dated June 14, 1991.

(3) If the slider cannot be pulled out of the track in either the deployed or stowed positions, record the percent engagement of the sliders in the lower auxiliary tracks, and repeat the inspection at the specified intervals in accordance with the accomplishment instructions of Boeing Alert Service Letter 737-SL-78-22 (Telex M-7272-91-7201), dated November 6, 1991.

(b) Accomplishment of the replacement of the auxiliary track liner and, if applicable, rework or replacement of the slider fittings and the auxiliary tracks, in accordance with Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990, constitutes terminating action for the inspection requirements of paragraph (a) of this AD.

(c) An alternative method 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 (ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(d) 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.

(e) The inspections, repairs, and modifications shall be done in accordance with Boeing Alert Service Letter 737-SL-78-22 (sent to operators as Telex M-7272-91-7201), dated November 6, 1991; and Boeing Service Bulletin 737-78-1048, Revision 1, dated February 22, 1990, which contains the following list of effective pages:


Page Number	
Revision Level
	Date
1 - 4	
1
	February 22, 1990
5 - 44	
(original)
	November 22, 1989

The deactivation procedures shall be done in accordance with Chapter 78 of Boeing Document D6-32545, "Boeing 737 Dispatch Deviations Procedures Guide," dated June 14, 1991, which includes the following list of effective pages:

PAGE NUMBER	DATE
2.78-1.0,	June 14, 1991
2.78-1.2,	
2.78-2.0,	
2.78-3.0,	
2.78-4.0,	
2.78-6.0,	
2.78-7.0	
2.78-1.1	May 31, 1990
2.78-5.0	August 17, 1989

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C.

(f) This amendment (39-8106, AD 91-25-06) becomes effective on December 18, 1991.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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