AD 48-34-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Textron Aviation Inc. | Army AT-11 | Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes |
| aircraft | Textron Aviation Inc. | C18S | Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes |
| aircraft | Textron Aviation Inc. | D18C | Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes |
| aircraft | Textron Aviation Inc. | D18C-T | Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes |
| aircraft | Textron Aviation Inc. | D18S | Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes |
Unsafe Condition
NAS 144 bolts installed in the stabilizer attachment fittings may have bolt head dimensions outside the acceptable limit of 0.226 inch ±0.010 inch, resulting in under strength bolts. Cracks may occur in the fuselage to stabilizer attachment fitting P/N 437-186096 where the lower 1/4-inch rivet attaches the fitting to the fuselage.
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Required Actions
Inspect NAS 144 bolts to verify bolt head dimensions are within 0.226 inch ±0.010 inch; replace non-conforming bolts. Inspect fitting P/N 437-186096 for cracks at the lower 1/4-inch rivet attachment point.
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Compliance Time
at next periodic inspection
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Affected Aircraft
Beech Model AT-11, C18S Airplanes modified per Beech Service Bulletin D18-48 (AD 47-33-5) and D18C, D18S, D18C-T Airplanes modified per Beech Service Bulletin D18C-3 (AD 47-33-06)
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Stabilizer Attachment Fittings
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_48-34-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-34-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes Subject: Stabilizer Attachment Fittings Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Textron Aviation Inc. Model: Army AT-11 | C18S | D18C | D18C-T | D18S Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 48-34-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-34-01 SUBJECT HEADING: Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-34-01 BEECH: Applies to All Models AT-11, C18S Airplanes Which Have Been Modified in Accordance With Beech Service Bulletin D18-48 Referred to in AD 47-33-5 and All D18C, D18S and D18C-T Airplanes Which Have Been Modified in Accordance With Beech Service Bulletin D18C-3 Referred to in AD 47-33-06. Inspection required at next periodic inspection. Inspect the NAS 144 bolts, (identified by the stamped bolt head), installed in the revised stabilizer attachment fittings to determine that the depth of the outer dimension of the bolt head conforms to the acceptable limit of 0.226 inch plus or minus 0.010 inch. Bolts that do not meet this specification are under strength and must be replaced. Inspect the fuselage to stabilizer attachment fitting, P/N 437-186096, to determine that this fitting has not cracked where the lower 1/4-inch rivet attaches the fitting to the fuselage. (Beech Service Bulletin No. D18-51 covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_48-34-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 48-34-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes Subject: Stabilizer Attachment Fittings Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Textron Aviation Inc. Model: Army AT-11 | C18S | D18C | D18C-T | D18S 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: 48-34-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 48-34-01 SUBJECT HEADING: Airworthiness Directives; Beech Model AT-11, C18S, D18C, D18S and D18C-T Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 48-34-01 BEECH: Applies to All Models AT-11, C18S Airplanes Which Have Been Modified in Accordance With Beech Service Bulletin D18-48 Referred to in AD 47-33-5 and All D18C, D18S and D18C-T Airplanes Which Have Been Modified in Accordance With Beech Service Bulletin D18C-3 Referred to in AD 47-33-06. Inspection required at next periodic inspection. Inspect the NAS 144 bolts, (identified by the stamped bolt head), installed in the revised stabilizer attachment fittings to determine that the depth of the outer dimension of the bolt head conforms to the acceptable limit of 0.226 inch plus or minus 0.010 inch. Bolts that do not meet this specification are under strength and must be replaced. Inspect the fuselage to stabilizer attachment fitting, P/N 437-186096, to determine that this fitting has not cracked where the lower 1/4-inch rivet attaches the fitting to the fuselage. (Beech Service Bulletin No. D18-51 covers this same subject.) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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