AD 91-09-17

final rule

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

AD Number
91-09-17
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-251-AD
FR Citation
This information is not available.

Applicability

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

Unsafe Condition

Separation of the outboard flap from the airplane due to improper bolts or nuts securing the track forward support fitting of the inboard tracks.

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

Required Actions

Inspect bolts and nuts securing the track forward support fitting of the inboard tracks to determine their part numbers and material. Replace bolts with Boeing part numbers BACB30LE6, BACB30LE7, BACB30US6, or BACB30US7 if incorrect. Replace nuts with A286 CRES steel Boeing part number BACN10HR if incorrect. Inspections must be done visually or via eddy current as per Boeing Alert Service Bulletin 737-57A1202.

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

Compliance Time

Within the next 30 days after August 25, 1989 (for bolt inspections), or within the next 1,500 cycles or 6 months after August 6, 1990 or the effective date of this amendment (for nut inspections), whichever occurs first. Replacement must be done prior to further flight if non-compliant parts are found.

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

Affected Aircraft

Boeing Model 737-300 and -400 Series airplanes, line numbers 1001 through 1769 and 1771, as listed in Boeing Alert Service Bulletin 737-57A1202, Revision 1.

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

Federal Register Abstract

Track Support Bolts

Applicability Source Text

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AD Number:
91-09-17
Document Type:
AD Final Rules
Docket Number:
90-NM-251-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737-300 and -400 Series Airplanes
Subject:
Track Support Bolts
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/03/1991
Make:
The Boeing Company
Model:
737-300 Series | 737-400 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: 91-09-17
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-251-AD

AMENDMENT:   39-6984

AD NUMBER:   91-09-17

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

ACTION:  

SUMMARY:  

DATES:   Effective June 3, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-09-17 BOEING: Amendment 39-6984. Docket No. 90-NM-251-AD. Supersedes AD 90- 14-04.

Applicability: Model 737-300 and -400 series airplanes, line numbers 1001 through 1769 and 1771, as listed in Boeing Alert Service Bulletin 737-57A1202, Revision 1, dated April 26, 1990, certificated in any category.

Compliance is required as indicated, unless previously accomplished.

To prevent separation of the outboard flap from the airplane, accomplish the following:

A. For airplanes line numbers 1001 through 1762: Within the next 30 days after August 25, 1989 (the issuance date of Telegraphic AD T89-18-51), inspect the bolts used to secure the track forward support fitting of the inboard tracks to determine the bolt head designation.

B. If a bolt other than Boeing part numbers BACB30LE6 or BACB30LE7, (A286 CRES steel) or BACB30US6 or BACB30US7 (Inconel), is found installed as a result of the inspection required by paragraph A. of this AD, prior to further flight, replace it with a proper bolt and nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

C. For airplanes line numbers 1001 through 1762, within the next 1,500 cycles or 6 months after August 6, 1990 (the effective date of amendment 39-6643), whichever occurs first, visually or eddy current inspect the nuts used to secure the track forward support fitting of the inboard track to determine nut material, in accordance with Boeing Alert Service Bulletin 737- 57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

NOTE: Inspection of the nuts must be accomplished even if the part numbers of the bolts were previously determined to be correct.

D. If a nut other than A286 CRES steel, Boeing part number BACN10HR, is found installed as a result of the inspection required by paragraph C. of this AD, prior to further flight, replace it with a proper nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

E. For airplanes line numbers 1763 through 1769 and 1771: Within the next 1,500 cycles or 6 months after the effective date of this Amendment, whichever occurs first, visually or eddy current inspect the nuts used to secure the track forward support fitting of the inboard track to determine the nut material, in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

F. If a nut other than A286 CRES steel, Boeing part number BACN10HR, is found installed as a result of the inspection required by paragraph E. of this AD, prior to further flight, replace it with a proper nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

G. 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.

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

H. 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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington.

Airworthiness Directive 90-14-04 superseded telegraphic AD T89-18-51.
Airworthiness Directive 91-09-17 supersedes AD 90-14-04, Amendment 39-6643.
This amendment (39-6984, AD 91-09-17) becomes effective on June 3, 1991.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_91-09-17.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
91-09-17
Document Type:
AD Final Rules
Docket Number:
90-NM-251-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737-300 and -400 Series Airplanes
Subject:
Track Support Bolts
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/03/1991
Make:
The Boeing Company
Model:
737-300 Series | 737-400 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: 91-09-17
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-251-AD

AMENDMENT:   39-6984

AD NUMBER:   91-09-17

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

ACTION:  

SUMMARY:  

DATES:   Effective June 3, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-09-17 BOEING: Amendment 39-6984. Docket No. 90-NM-251-AD. Supersedes AD 90- 14-04.

Applicability: Model 737-300 and -400 series airplanes, line numbers 1001 through 1769 and 1771, as listed in Boeing Alert Service Bulletin 737-57A1202, Revision 1, dated April 26, 1990, certificated in any category.

Compliance is required as indicated, unless previously accomplished.

To prevent separation of the outboard flap from the airplane, accomplish the following:

A. For airplanes line numbers 1001 through 1762: Within the next 30 days after August 25, 1989 (the issuance date of Telegraphic AD T89-18-51), inspect the bolts used to secure the track forward support fitting of the inboard tracks to determine the bolt head designation.

B. If a bolt other than Boeing part numbers BACB30LE6 or BACB30LE7, (A286 CRES steel) or BACB30US6 or BACB30US7 (Inconel), is found installed as a result of the inspection required by paragraph A. of this AD, prior to further flight, replace it with a proper bolt and nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

C. For airplanes line numbers 1001 through 1762, within the next 1,500 cycles or 6 months after August 6, 1990 (the effective date of amendment 39-6643), whichever occurs first, visually or eddy current inspect the nuts used to secure the track forward support fitting of the inboard track to determine nut material, in accordance with Boeing Alert Service Bulletin 737- 57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

NOTE: Inspection of the nuts must be accomplished even if the part numbers of the bolts were previously determined to be correct.

D. If a nut other than A286 CRES steel, Boeing part number BACN10HR, is found installed as a result of the inspection required by paragraph C. of this AD, prior to further flight, replace it with a proper nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

E. For airplanes line numbers 1763 through 1769 and 1771: Within the next 1,500 cycles or 6 months after the effective date of this Amendment, whichever occurs first, visually or eddy current inspect the nuts used to secure the track forward support fitting of the inboard track to determine the nut material, in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

F. If a nut other than A286 CRES steel, Boeing part number BACN10HR, is found installed as a result of the inspection required by paragraph E. of this AD, prior to further flight, replace it with a proper nut in accordance with Boeing Alert Service Bulletin 737-57A1202, dated August 24, 1989, or Revision 1, dated April 26, 1990.

G. 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.

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

H. 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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington.

Airworthiness Directive 90-14-04 superseded telegraphic AD T89-18-51.
Airworthiness Directive 91-09-17 supersedes AD 90-14-04, Amendment 39-6643.
This amendment (39-6984, AD 91-09-17) becomes effective on June 3, 1991.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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