AD 53-09-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Continental | W-670-9A | CONTINENTAL Model W-670-9A Engines |
Unsafe Condition
Propeller blade fatigue failures due to lack of suitable propeller vibration stress data.
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Required Actions
Disassemble and inspect blades for cracks via shank area etching under hub clamp rings. Cut propeller diameter between 102 inches maximum and 100 inches minimum. Set blade angle for static r.p.m. between 1,500 and 1,975. Install propeller in zero degree position. Placard aircraft with rpm restriction. Remove tip region nicks/gouges and maintain per CAM 18.
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Compliance Time
not later than May 15, 1953
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Affected Aircraft
All aircraft with Continental W-670-9A engines and ground adjustable propellers with blades 11C1 (Hamilton Standard) or 4350, 4350F, 4350F1 (Navy model designations).
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Federal Register Abstract
Propeller Blades
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_53-09-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 53-09-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: CONTINENTAL Model W-670-9A Engines Subject: Propeller Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Continental Model: W-670-9A Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 53-09-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 53-09-04 SUBJECT HEADING: CONTINENTAL Model W-670-9A Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 53-09-04 CONTINENTAL: Applies to All Aircraft Equipped With Continental W-670-9A (Ordnance-Tank) Engines and Ground Adjustable Propellers Having Blades 11C1 (Hamilton Standard Model Designation) or 4350, 4350F, or 4350F1 (Navy Model Designation.) Compliance required not later than May 15, 1953. In the absence of suitable propeller vibration stress data, the following precautionary measures should be taken to minimize the possibility of propeller blade fatigue failures: (1) Disassemble propeller and inspect for cracks by etching the shank areas of the blades under the hub clamp rings. (2) Cut propellers to between 102 inches maximum and 100 inches minimum diameter. (3) Set blade angle so that static r.p.m. is between 1,500 and 1,975. (4) Install propeller on engine in the zero degree position (blades in line with crankthrow). (5) Placard airplane, "Do not exceed 1,900 r.p.m. for all operations except takeoff." (6) Remove all nicks and gouges from tip region and maintain propeller blades as outlined in Civil Aeronautics Manual 18. FOOTER:
Document Text
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AD Final Rules - DRS_53-09-04.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 53-09-04 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: CONTINENTAL Model W-670-9A Engines Subject: Propeller Blades Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Continental Model: W-670-9A Product Type: Engine Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 53-09-04 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 53-09-04 SUBJECT HEADING: CONTINENTAL Model W-670-9A Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 53-09-04 CONTINENTAL: Applies to All Aircraft Equipped With Continental W-670-9A (Ordnance-Tank) Engines and Ground Adjustable Propellers Having Blades 11C1 (Hamilton Standard Model Designation) or 4350, 4350F, or 4350F1 (Navy Model Designation.) Compliance required not later than May 15, 1953. In the absence of suitable propeller vibration stress data, the following precautionary measures should be taken to minimize the possibility of propeller blade fatigue failures: (1) Disassemble propeller and inspect for cracks by etching the shank areas of the blades under the hub clamp rings. (2) Cut propellers to between 102 inches maximum and 100 inches minimum diameter. (3) Set blade angle so that static r.p.m. is between 1,500 and 1,975. (4) Install propeller on engine in the zero degree position (blades in line with crankthrow). (5) Placard airplane, "Do not exceed 1,900 r.p.m. for all operations except takeoff." (6) Remove all nicks and gouges from tip region and maintain propeller blades as outlined in Civil Aeronautics Manual 18. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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