AD 44-20-02

final rule

BOEING 307 Series Aircraft

AD Number
44-20-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company S-307 BOEING 307 Series Aircraft
aircraft The Boeing Company SA-307B BOEING 307 Series Aircraft
aircraft The Boeing Company SA-307B-1 BOEING 307 Series Aircraft

Unsafe Condition

Cracks in square aluminum alloy 24SRT tubing in wing spars, front and rear spar fuselage bulkheads, and fin and stabilizer attachment bulkheads may progress rapidly once initiated, leading to structural failure.

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

Required Actions

Inspect all square aluminum alloy 24SRT tubing in specified locations visually at intervals per model: SA-307B requires inspections every 150 hours or 90 days, detailed inspections annually or at engine overhaul, and annual x-ray inspections. SA-307B-1 and S-307 require inspections every 850 hours/120 days and 700 hours/120 days respectively. Report defects to FAA and repair as directed.

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

Compliance Time

before further flight

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

Affected Aircraft

Boeing S-307, SA-307B, SA-307B-1 aircraft

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

Federal Register Abstract

Tubing

Applicability Source Text

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AD Final Rules - DRS_44-20-02.html
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AD Number:
44-20-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
BOEING 307 Series Aircraft
Subject:
Tubing
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
The Boeing Company
Model:
S-307 | SA-307B | SA-307B-1
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Superseded AD: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Superseded By: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: 44-20-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   44-20-02

SUBJECT HEADING:   BOEING 307 Series Aircraft

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   44-20-02 BOEING: (Was Service Note 1 of AD 719-1 and Service Note 1 of AD-726-1.) Applies to 307 Series Aircraft.
Inspect by visual means all square aluminum alloy 24SRT tubing for cracks in the following locations: wing spars, front spar fuselage bulkhead, rear spar fuselage bulkhead, and fin and stabilizer attachment bulkheads. These inspections shall be conducted at intervals specified and in the following manner:
A. SA-307B. In the inspection of 24SRT members in this model airplane, it is recommended that the visual inspection procedure outlined for Boeing Model 314 and A-314 under AD 45-04-01 be followed. If defects are located, they shall be reported to the FAA for evaluation. Past experience has shown that once cracking starts, it may progress at a rapid rate, thus requiring closer inspections and corrective action. It shall also be the operator's responsibility to keep a record of all cracks on this model airplane. This record shall be revised periodically to show the status of existing cracks and to record newly developed cracks. Copies of the original report and all revised pages should be submitted to the FAA for examination.
1. INSPECTIONS OF READILY ACCESSIBLE AREAS. These inspections shall be conducted at intervals not to exceed 150 hours of operation or 90 days, whichever occurs first. This inspection is intended to cover only those portions of 24SRT tubing that are accessible to visual inspection through available inspection panels, removal of gap strips and the openings in the nacelles.
2. DETAILED INSPECTIONS. These inspections will be conducted annually or at engine overhaul periods, whichever occurs first. This inspection is required of all 24SRT tubing visible through all available inspection panels, removal of gap strips, leading edges, wing tips, stress plates and fuel tanks. The use of at least a 10-power glass will be required. To more thoroughly cover the wing area, it will be necessary for a man to crawl outboard in the wings as far as possible.
3. X-RAY INSPECTION. This type of inspection is required annually. Inspect by x- ray all inaccessible portions of the 24SRT spar chord members for their entire length. This inspection may coincide with annual inspection noted under 2.
B. SA-307B-1. At intervals not to exceed 850 hours of operation or 120 days, whichever occurs first. If defects are located, they shall be repaired in a manner satisfactory to the FAA.
C. S-307. At intervals not to exceed 700 hours of operation or 120 days, whichever occurs first. If defects are located, they shall be repaired in a manner satisfactory to the FAA.



FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_44-20-02.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
44-20-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
BOEING 307 Series Aircraft
Subject:
Tubing
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
The Boeing Company
Model:
S-307 | SA-307B | SA-307B-1
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: 44-20-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   44-20-02

SUBJECT HEADING:   BOEING 307 Series Aircraft

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   44-20-02 BOEING: (Was Service Note 1 of AD 719-1 and Service Note 1 of AD-726-1.) Applies to 307 Series Aircraft.
Inspect by visual means all square aluminum alloy 24SRT tubing for cracks in the following locations: wing spars, front spar fuselage bulkhead, rear spar fuselage bulkhead, and fin and stabilizer attachment bulkheads. These inspections shall be conducted at intervals specified and in the following manner:
A. SA-307B. In the inspection of 24SRT members in this model airplane, it is recommended that the visual inspection procedure outlined for Boeing Model 314 and A-314 under AD 45-04-01 be followed. If defects are located, they shall be reported to the FAA for evaluation. Past experience has shown that once cracking starts, it may progress at a rapid rate, thus requiring closer inspections and corrective action. It shall also be the operator's responsibility to keep a record of all cracks on this model airplane. This record shall be revised periodically to show the status of existing cracks and to record newly developed cracks. Copies of the original report and all revised pages should be submitted to the FAA for examination.
1. INSPECTIONS OF READILY ACCESSIBLE AREAS. These inspections shall be conducted at intervals not to exceed 150 hours of operation or 90 days, whichever occurs first. This inspection is intended to cover only those portions of 24SRT tubing that are accessible to visual inspection through available inspection panels, removal of gap strips and the openings in the nacelles.
2. DETAILED INSPECTIONS. These inspections will be conducted annually or at engine overhaul periods, whichever occurs first. This inspection is required of all 24SRT tubing visible through all available inspection panels, removal of gap strips, leading edges, wing tips, stress plates and fuel tanks. The use of at least a 10-power glass will be required. To more thoroughly cover the wing area, it will be necessary for a man to crawl outboard in the wings as far as possible.
3. X-RAY INSPECTION. This type of inspection is required annually. Inspect by x- ray all inaccessible portions of the 24SRT spar chord members for their entire length. This inspection may coincide with annual inspection noted under 2.
B. SA-307B-1. At intervals not to exceed 850 hours of operation or 120 days, whichever occurs first. If defects are located, they shall be repaired in a manner satisfactory to the FAA.
C. S-307. At intervals not to exceed 700 hours of operation or 120 days, whichever occurs first. If defects are located, they shall be repaired in a manner satisfactory to the FAA.



FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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