AD 50-38-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | AT-6 (SNJ-2) | Airworthiness Directives; North American Model AT-6 Series Aircraft |
| aircraft | The Boeing Company | AT-6A (SNJ-3) | Airworthiness Directives; North American Model AT-6 Series Aircraft |
| aircraft | The Boeing Company | AT-6B | Airworthiness Directives; North American Model AT-6 Series Aircraft |
| aircraft | The Boeing Company | AT-6C (SNJ-4) | Airworthiness Directives; North American Model AT-6 Series Aircraft |
| aircraft | The Boeing Company | AT-6D (SNJ-5) | Airworthiness Directives; North American Model AT-6 Series Aircraft |
| aircraft | The Boeing Company | AT-6F (SNJ-6) | Airworthiness Directives; North American Model AT-6 Series Aircraft |
Unsafe Condition
Intergranular corrosion in structural aluminum alloy components of the fuselage and wings may lead to structural failure.
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Required Actions
Inspect all accessible structural aluminum alloy components for intergranular corrosion using visual and tactile methods with a screwdriver. Replace all corroded parts.
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Compliance Time
at the next annual inspection and at each succeeding annual inspection thereafter
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Affected Aircraft
North American Model AT-6 Series Aircraft including AT-6 (SNJ-2), AT-6A (SNJ-3), AT-6B, AT-6C (SNJ-4), AT-6D (SNJ-5), AT-6F (SNJ-6)
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Federal Register Abstract
Fuselage Structure Corrosion
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_50-38-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-38-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; North American Model AT-6 Series Aircraft Subject: Fuselage Structure Corrosion Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: AT-6 (SNJ-2) | AT-6A (SNJ-3) | AT-6B | AT-6C (SNJ-4) | AT-6D (SNJ-5) | AT-6F (SNJ-6) Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 50-38-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-38-01 SUBJECT HEADING: Airworthiness Directives; North American Model AT-6 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-38-01 NORTH AMERICAN: Applies to All Model AT-6 Series Aircraft. To be accomplished at the next annual inspection and at each succeeding annual inspection thereafter. Several recent incidents have indicated that the inspections presently required are not sufficiently comprehensive to reveal all areas of the airplane which may have been adversely affected by intergranular corrosion, and that the required inspections should be repeated periodically. Accordingly, in order to minimize the possibility of structural failure due to such corrosion, the following must be accomplished: Inspect all accessible structural aluminum alloy components for evidence of intergranular corrosion particularly in the following locations: At the upper and lower deck and the most forward and two aft bulkheads in the monocoque fuselage; frame around the baggage door; inboard end of horizontal stabilizer spars; fuel cell doors in the wing center section; wing attach angles; two inboard ribs on each outer wing; trailing edge ribs above flaps; and the outboard rib of the wings, especially at the trailing edge. Full use should be made of all access provisions to accomplish as thorough an inspection as possible. In conducting these inspections, full reliance cannot be placed on visual examination alone. A screwdriver or other instrument should be used to explore for dull sounding areas and for material which may be penetrated easily by pressure applied to the screwdriver tip or similar sharp point. Areas adjacent to joints and sheared edges should be examined thoroughly. Formed material in particular has been found to be subject to rapid intergranular corrosion, because of poor heat treatment of parts, which were formed in the annealed condition, and later heat treated. All corroded parts must be replaced. This supersedes AD 47-41-01. FOOTER:
Document Text
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AD Final Rules - DRS_50-38-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 50-38-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; North American Model AT-6 Series Aircraft Subject: Fuselage Structure Corrosion Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: AT-6 (SNJ-2) | AT-6A (SNJ-3) | AT-6B | AT-6C (SNJ-4) | AT-6D (SNJ-5) | AT-6F (SNJ-6) Product Type: Aircraft Product Subtype: Small 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: 50-38-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 50-38-01 SUBJECT HEADING: Airworthiness Directives; North American Model AT-6 Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 50-38-01 NORTH AMERICAN: Applies to All Model AT-6 Series Aircraft. To be accomplished at the next annual inspection and at each succeeding annual inspection thereafter. Several recent incidents have indicated that the inspections presently required are not sufficiently comprehensive to reveal all areas of the airplane which may have been adversely affected by intergranular corrosion, and that the required inspections should be repeated periodically. Accordingly, in order to minimize the possibility of structural failure due to such corrosion, the following must be accomplished: Inspect all accessible structural aluminum alloy components for evidence of intergranular corrosion particularly in the following locations: At the upper and lower deck and the most forward and two aft bulkheads in the monocoque fuselage; frame around the baggage door; inboard end of horizontal stabilizer spars; fuel cell doors in the wing center section; wing attach angles; two inboard ribs on each outer wing; trailing edge ribs above flaps; and the outboard rib of the wings, especially at the trailing edge. Full use should be made of all access provisions to accomplish as thorough an inspection as possible. In conducting these inspections, full reliance cannot be placed on visual examination alone. A screwdriver or other instrument should be used to explore for dull sounding areas and for material which may be penetrated easily by pressure applied to the screwdriver tip or similar sharp point. Areas adjacent to joints and sheared edges should be examined thoroughly. Formed material in particular has been found to be subject to rapid intergranular corrosion, because of poor heat treatment of parts, which were formed in the annealed condition, and later heat treated. All corroded parts must be replaced. This supersedes AD 47-41-01. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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