AD 47-33-06

final rule

Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes

AD Number
47-33-06
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of a riveted aircraft structural panel and frame
Problem area Airframe structure

Applicability

TypeManufacturerModelDetails
aircraft Textron Aviation Inc. D18C Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes
aircraft Textron Aviation Inc. D18C-T Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes
aircraft Textron Aviation Inc. D18S Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes

Unsafe Condition

Cracks developing in the stabilizer main spar and subspar.

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

Required Actions

Replace the center section of the main spar with one having the lower flange-web radius cutout approximately 2 inches from either end. Install two 0.064-inch dural channels (404-186053) between new attachment fittings (437-186095 and 6) and the main spar web. Rivet an 0.032-inch dural doubler (404-186052) to the lower skin, main spar, and center nose rib flanges. Cut off the forward part of the upper flanges of each stabilizer-fuselage attaching angle as far back as the sixth screw hole, plug the corresponding 12 holes in the stabilizer, remove the three-screw outboard section of the gang nut on each side of the stabilizer subspar, and plug the corresponding holes in the No. 13 bulkhead angle.

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

Compliance Time

prior to November 1, 1947

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

Affected Aircraft

Beech Models D18C, D18S, and D18C-T Airplanes with serial numbers AA-1 to AA-21, inclusive, and AA-23 to AA-26, inclusive.

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

Federal Register Abstract

Stabilizer Spar Replacement

Applicability Source Text

Show captured applicability text from the source AD
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AD Number:
47-33-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes
Subject:
Stabilizer Spar Replacement
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Textron Aviation Inc.
Model:
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: 47-33-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   47-33-06

SUBJECT HEADING:   Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
47-33-06 BEECH: (Was Mandatory Note 1 of AD-770-1 and Mandatory Note 1 of AD- 765-1.) Applies to D18C, D18S and D18C-T Aircraft Serial Numbers AA-1 to AA-21, Inclusive, and AA-23 to AA-26, Inclusive.

Compliance required prior to November 1, 1947.

To eliminate the possibility of cracks developing in the stabilizer main spar and subspar, the center section of the main spar must be replaced with one having the lower flange-web radius cutout approximately 2 inches from either end. Two 0.064-inch dural channels (404-186053) should be installed between the new attachment fittings (437-186095 and 6) and the main spar web. At the main spar attachment fittings, an 0.032-inch dural doubler (404-186052) should be riveted to the lower skin, the main spar, and the center nose rib flanges.

The forward part of the upper flanges of each stabilizer-fuselage attaching angle should be cut off as far back as the sixth screw hole. The corresponding 12 holes in the stabilizer should be plugged. A three-screw outboard section of the gang nut on each side of the stabilizer subspar should be removed and the corresponding holes in the No. 13 bulkhead angle plugged. The revision of the stabilizer attachment eliminates the necessity for further inspection for cracks except as made during the normal periodic inspection.

(Beech Service Bulletin No. D18C-3 covers this same subject.)

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_47-33-06.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
47-33-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes
Subject:
Stabilizer Spar Replacement
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Textron Aviation Inc.
Model:
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: 47-33-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   47-33-06

SUBJECT HEADING:   Airworthiness Directives; Beech Models D18C, D18S and D18C-T Airplanes

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
47-33-06 BEECH: (Was Mandatory Note 1 of AD-770-1 and Mandatory Note 1 of AD- 765-1.) Applies to D18C, D18S and D18C-T Aircraft Serial Numbers AA-1 to AA-21, Inclusive, and AA-23 to AA-26, Inclusive.

Compliance required prior to November 1, 1947.

To eliminate the possibility of cracks developing in the stabilizer main spar and subspar, the center section of the main spar must be replaced with one having the lower flange-web radius cutout approximately 2 inches from either end. Two 0.064-inch dural channels (404-186053) should be installed between the new attachment fittings (437-186095 and 6) and the main spar web. At the main spar attachment fittings, an 0.032-inch dural doubler (404-186052) should be riveted to the lower skin, the main spar, and the center nose rib flanges.

The forward part of the upper flanges of each stabilizer-fuselage attaching angle should be cut off as far back as the sixth screw hole. The corresponding 12 holes in the stabilizer should be plugged. A three-screw outboard section of the gang nut on each side of the stabilizer subspar should be removed and the corresponding holes in the No. 13 bulkhead angle plugged. The revision of the stabilizer attachment eliminates the necessity for further inspection for cracks except as made during the normal periodic inspection.

(Beech Service Bulletin No. D18C-3 covers this same subject.)

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.