AD 90-21-15

final rule

Airworthiness Directives; BOEING Model 737 Series Airplanes

AD Number
90-21-15
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-75-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 737-100 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-200 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-200C Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-300 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-400 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-500 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-600 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-700 Series Airworthiness Directives; BOEING Model 737 Series Airplanes
aircraft The Boeing Company 737-800 Series Airworthiness Directives; BOEING Model 737 Series Airplanes

Unsafe Condition

Cracking in the horizontal stabilizer center section rear spar upper chord near the beam gusset plates.

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

Required Actions

Eddy current or dye penetrant inspect the upper surface of the forward flange of the horizontal stabilizer center section rear spar upper chord for cracks near each beam gusset plate. Repair, modify, or replace damaged chord before further flight if cracks are found. Resume repetitive inspections after repair, modification, or replacement as per specified landing intervals.

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

Compliance Time

Prior to the accumulation of 35,000 landings, or within 350 landings after October 18, 1982, whichever occurs later, unless accomplished within the last 4,150 landings, and thereafter at intervals not to exceed 4,500 landings since the last inspection.

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

Affected Aircraft

Boeing Model 737 series airplanes listed in Boeing Alert Service Bulletin 737-55A1031, Revision 2, dated November 30, 1989, certificated in any category.

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

Federal Register Abstract

Horizontal Stabilizer

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_90-21-15.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
90-21-15
Document Type:
AD Final Rules
Docket Number:
90-NM-75-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737 Series Airplanes
Subject:
Horizontal Stabilizer
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/16/1990
Make:
The Boeing Company
Model:
737-100 Series | 737-200 Series | 737-200C Series | 737-300 Series | 737-400 Series | 737-500 Series...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: 90-21-15
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-75-AD

AMENDMENT:   39-6767

AD NUMBER:   90-21-15

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 737 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective November 16, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-21-15 BOEING: Amendment 39-6767. Docket No. 90-NM-75-AD.

Applicability: Model 737 series airplanes, listed in Boeing Alert Service Bulletin 737- 55A1031, Revision 2, dated November 30, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To detect cracking in the horizontal stabilizer center section rear spar upper chord, accomplish the following:

A. Prior to the accumulation of 35,000 landings, or within 350 landings after October 18, 1982 (the effective date of AD 82-21-02, Amendment 39-4473), whichever occurs later, unless accomplished within the last 4,150 landings, and thereafter at intervals not to exceed 4,500 landings since the last inspection, eddy current or dye penetrant inspect the upper surface of the forward flange of the horizontal stabilizer center section rear spar upper chord for cracks in the area of each beam gusset plate in accordance with "Part A-Inspection" of Boeing Alert Service Bulletin 737-55A1031, Revision 2, dated November 30, 1989, or previous FAA- approved revisions. If cracks are found, repair, modify, or replace the damaged chord before further flight, in accordance with Boeing Model 737 Structural Repair Manual, Subject 51-30-09, or Boeing Alert Service Bulletin 737-55A1031, Revision 2, dated November 30, 1989, or previous FAA-approved revisions.

B. After repair, modification, or replacement, resume the repetitive inspections required by paragraph A. of this AD, at the following schedule or within the next 1,000 landings, whichever occurs later:

1. Prior to the accumulation of 9,000 landings after repair.

2. Prior to the accumulation of 35,000 landings after modification.

3. Prior to the accumulation of 50,000 landings after replacement.

Thereafter, repeat the inspections at intervals not to exceed 4,500 landings.

C. 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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the 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.

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 S.W., Renton, Washington 98055-4056.

Airworthiness Directive 90-21-15 supersedes AD 82-21-02, Amendment 39-4473.
This amendment (39-6767, AD 90-21-15) becomes effective on November 16, 1990.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_90-21-15.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
90-21-15
Document Type:
AD Final Rules
Docket Number:
90-NM-75-AD
Subject Heading:
Airworthiness Directives; BOEING Model 737 Series Airplanes
Subject:
Horizontal Stabilizer
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/16/1990
Make:
The Boeing Company
Model:
737-100 Series | 737-200 Series | 737-200C Series | 737-300 Series | 737-400 Series | 737-500 Series...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: 90-21-15
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-75-AD

AMENDMENT:   39-6767

AD NUMBER:   90-21-15

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 737 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective November 16, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-21-15 BOEING: Amendment 39-6767. Docket No. 90-NM-75-AD.

Applicability: Model 737 series airplanes, listed in Boeing Alert Service Bulletin 737- 55A1031, Revision 2, dated November 30, 1989, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To detect cracking in the horizontal stabilizer center section rear spar upper chord, accomplish the following:

A. Prior to the accumulation of 35,000 landings, or within 350 landings after October 18, 1982 (the effective date of AD 82-21-02, Amendment 39-4473), whichever occurs later, unless accomplished within the last 4,150 landings, and thereafter at intervals not to exceed 4,500 landings since the last inspection, eddy current or dye penetrant inspect the upper surface of the forward flange of the horizontal stabilizer center section rear spar upper chord for cracks in the area of each beam gusset plate in accordance with "Part A-Inspection" of Boeing Alert Service Bulletin 737-55A1031, Revision 2, dated November 30, 1989, or previous FAA- approved revisions. If cracks are found, repair, modify, or replace the damaged chord before further flight, in accordance with Boeing Model 737 Structural Repair Manual, Subject 51-30-09, or Boeing Alert Service Bulletin 737-55A1031, Revision 2, dated November 30, 1989, or previous FAA-approved revisions.

B. After repair, modification, or replacement, resume the repetitive inspections required by paragraph A. of this AD, at the following schedule or within the next 1,000 landings, whichever occurs later:

1. Prior to the accumulation of 9,000 landings after repair.

2. Prior to the accumulation of 35,000 landings after modification.

3. Prior to the accumulation of 50,000 landings after replacement.

Thereafter, repeat the inspections at intervals not to exceed 4,500 landings.

C. 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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the 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.

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 S.W., Renton, Washington 98055-4056.

Airworthiness Directive 90-21-15 supersedes AD 82-21-02, Amendment 39-4473.
This amendment (39-6767, AD 90-21-15) becomes effective on November 16, 1990.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.