AD 53-15-02

final rule

LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.

AD Number
53-15-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Lockheed Aircraft Corporation 149-46 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
aircraft Lockheed Aircraft Corporation 49-46 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
aircraft Lockheed Aircraft Corporation 649-79 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
aircraft Lockheed Aircraft Corporation 649A-79 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
aircraft Lockheed Aircraft Corporation 749-79 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
aircraft Lockheed Aircraft Corporation 749A-79 LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.

Unsafe Condition

Cracks in the forward flange of the lower front spar cap at wing Station 326, left and right, particularly in spar cap joggle areas, which may extend into the vertical leg and compromise structural integrity.

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

Required Actions

Inspect for cracks using dye penetrant inspection or equivalent. Stop drill cracks not extending into the vertical leg unless terminating in a rivet hole, repair permanently, or install serviceable repair per LAC Drawing 325800. If cracks extend into the vertical leg, remove tank sealant for skin and web inspection, then install reinforcement per LAC Drawing 325667, change A or equivalent. Reinforce before resuming commercial operation. Reinspect periodically as specified.

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

Compliance Time

At the first arrival at the main base, unless already accomplished.

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

Affected Aircraft

Lockheed Models 049, 149, 649, and 749 Series Aircraft.

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

Federal Register Abstract

Wing Lower Front Spar Cap

Applicability Source Text

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AD Number:
53-15-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
Subject:
Wing Lower Front Spar Cap
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Lockheed Aircraft Corporation
Model:
149-46 | 49-46 | 649-79 | 649A-79 | 749-79 | 749A-79
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: 53-15-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   53-15-02

SUBJECT HEADING:   LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
53-15-02 LOCKHEED: Applies to All Models 049, 149, 649 and 749 Series Aircraft.

Compliance required as indicated.

At the first arrival at the main base, unless already accomplished, inspect for cracks in the forward flange of the lower front spar cap at wing Station 326, left and right, with particular reference to spar cap joggle areas using dye penetrant inspection method or equivalent.

1. If crack is found in the forward flange and does not extend into the vertical leg, stop drill the crack unless it terminates in a rivet hole and make permanent repair or install the serviceable repair in accordance with LAC Drawing 325800. When serviceable repair is used, a visual inspection must be conducted at periodic intervals not to exceed 50 hours with dye penetrant inspection or equivalent method to be used at periods not to exceed every 200 hours until incorporation of the reinforcement per LAC Drawing 325667, change A or equivalent.

2. If crack in the front spar flange extends into the vertical leg, remove tank sealant as necessary for skin and web inspection using dye penetrant inspection method or equivalent. Reinforcement per LAC Drawing 325667, change A or equivalent is necessary before resuming commercial operation and normal inspection procedures.

3. If no cracks are found, reinspect using dye penetrant inspection method or equivalent on all aircraft with 10,000 hours or more total flight time, at intervals not to exceed 200 hours, and on all other aircraft at each major airframe inspection period until such time as reinforcement per LAC Drawing 325667, change A or equivalent is accomplished.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_53-15-02.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
53-15-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.
Subject:
Wing Lower Front Spar Cap
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Lockheed Aircraft Corporation
Model:
149-46 | 49-46 | 649-79 | 649A-79 | 749-79 | 749A-79
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: 53-15-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   53-15-02

SUBJECT HEADING:   LOCKHEED Models 049, 149, 649 and 749 Series Aircraft.

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
53-15-02 LOCKHEED: Applies to All Models 049, 149, 649 and 749 Series Aircraft.

Compliance required as indicated.

At the first arrival at the main base, unless already accomplished, inspect for cracks in the forward flange of the lower front spar cap at wing Station 326, left and right, with particular reference to spar cap joggle areas using dye penetrant inspection method or equivalent.

1. If crack is found in the forward flange and does not extend into the vertical leg, stop drill the crack unless it terminates in a rivet hole and make permanent repair or install the serviceable repair in accordance with LAC Drawing 325800. When serviceable repair is used, a visual inspection must be conducted at periodic intervals not to exceed 50 hours with dye penetrant inspection or equivalent method to be used at periods not to exceed every 200 hours until incorporation of the reinforcement per LAC Drawing 325667, change A or equivalent.

2. If crack in the front spar flange extends into the vertical leg, remove tank sealant as necessary for skin and web inspection using dye penetrant inspection method or equivalent. Reinforcement per LAC Drawing 325667, change A or equivalent is necessary before resuming commercial operation and normal inspection procedures.

3. If no cracks are found, reinspect using dye penetrant inspection method or equivalent on all aircraft with 10,000 hours or more total flight time, at intervals not to exceed 200 hours, and on all other aircraft at each major airframe inspection period until such time as reinforcement per LAC Drawing 325667, change A or equivalent is accomplished.

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.